android 属性动画入门

前面关于tween动画写了2篇博客,如果那2篇博客都看懂了,估计Tween动画理解使用起来问题就不大,之前也说了Tween动画的缺点就是在交互上有bug,今天就讲下属性动画,属性动画就能解决Tween动画交互上的问题,由于下周工作上很忙,估计要花一周时间把这篇博客写完,一些常见的动画demo,都在写出来,希望每个人都能看的懂,切入正题,

属性动画英文叫Property Animator,它包括ValueAnimator和ObjectAnimator,我们先看ValueAnimator这个类,从类名字直观的就是叫值动画,对吧,那么这和Tween动画不同的是Tween动画是叫view
animation,作用于控件上的,如果看过ValueAnimator类的源码就知道它是继承了Animator这个类,现在看下Animator类的源码,看看它给我们提供了什么方法让我们去调用,这个类的源码是我把注释删除了,代码量很少,才200多行

package android.animation;

import android.content.res.ConstantState;

import java.util.ArrayList;

public abstract class Animator implements Cloneable {

    /**

     * The set of listeners to be sent events through the life of an animation.

     */

    ArrayList<AnimatorListener> mListeners = null;

    /**

     * The set of listeners to be sent pause/resume events through the life

     * of an animation.

     */

    ArrayList<AnimatorPauseListener> mPauseListeners = null;

    /**

     * Whether this animator is currently in a paused state.

     */

    boolean mPaused = false;

  

    int mChangingConfigurations = 0;

    private AnimatorConstantState mConstantState;

    public void start() {

    }

    public void cancel() {

    }

    public void end() {

    }

    public void pause() {

        if (isStarted() && !mPaused) {

            mPaused = true;

            if (mPauseListeners != null) {

                ArrayList<AnimatorPauseListener> tmpListeners =

                        (ArrayList<AnimatorPauseListener>) mPauseListeners.clone();

                int numListeners = tmpListeners.size();

                for (int i = 0; i < numListeners; ++i) {

                    tmpListeners.get(i).onAnimationPause(this);

                }

            }

        }

    }

    public void resume() {

        if (mPaused) {

            mPaused = false;

            if (mPauseListeners != null) {

                ArrayList<AnimatorPauseListener> tmpListeners =

                        (ArrayList<AnimatorPauseListener>) mPauseListeners.clone();

                int numListeners = tmpListeners.size();

                for (int i = 0; i < numListeners; ++i) {

                    tmpListeners.get(i).onAnimationResume(this);

                }

            }

        }

    }

    public boolean isPaused() {

        return mPaused;

    }

    public abstract long getStartDelay();

    public abstract void setStartDelay(long startDelay);

    public abstract Animator setDuration(long duration);

    public abstract long getDuration();

    public abstract void setInterpolator(TimeInterpolator value);

    public TimeInterpolator getInterpolator() {

        return null;

    }

    public abstract boolean isRunning();

    public boolean isStarted() {

        // Default method returns value for isRunning(). Subclasses should override to return a

        // real value.

        return isRunning();

    }

    public void addListener(AnimatorListener listener) {

        if (mListeners == null) {

            mListeners = new ArrayList<AnimatorListener>();

        }

        mListeners.add(listener);

    }

    public void removeListener(AnimatorListener listener) {

        if (mListeners == null) {

            return;

        }

        mListeners.remove(listener);

        if (mListeners.size() == 0) {

            mListeners = null;

        }

    } 

    public ArrayList<AnimatorListener> getListeners() {

        return mListeners;

    }

    public void addPauseListener(AnimatorPauseListener listener) {

        if (mPauseListeners == null) {

            mPauseListeners = new ArrayList<AnimatorPauseListener>();

        }

        mPauseListeners.add(listener);

    } 

    public void removePauseListener(AnimatorPauseListener listener) {

        if (mPauseListeners == null) {

            return;

        }

        mPauseListeners.remove(listener);

        if (mPauseListeners.size() == 0) {

            mPauseListeners = null;

        }

    }

    public void removeAllListeners() {

        if (mListeners != null) {

            mListeners.clear();

            mListeners = null;

        }

        if (mPauseListeners != null) {

            mPauseListeners.clear();

            mPauseListeners = null;

        }

    }

    public int getChangingConfigurations() {

        return mChangingConfigurations;

    }

    public void setChangingConfigurations(int configs) {

        mChangingConfigurations = configs;

    } 

    public void appendChangingConfigurations(int configs) {

        mChangingConfigurations |= configs;

    }

    public ConstantState<Animator> createConstantState() {

        return new AnimatorConstantState(this);

    }

    @Override

    public Animator clone() {

        try {

            final Animator anim = (Animator) super.clone();

            if (mListeners != null) {

                anim.mListeners = new ArrayList<AnimatorListener>(mListeners);

            }

            if (mPauseListeners != null) {

                anim.mPauseListeners = new ArrayList<AnimatorPauseListener>(mPauseListeners);

            }

            return anim;

        } catch (CloneNotSupportedException e) {

           throw new AssertionError();

        }

    }

    public void setupStartValues() {

    }

    public void setupEndValues() {

    }

    public void setTarget(Object target) {

    }

  

    public boolean canReverse() {

        return false;

    }

    /**

     * @hide

     */

    public void reverse() {

        throw new IllegalStateException("Reverse is not supported");

    }

    public static interface AnimatorListener { 

        void onAnimationStart(Animator animation);

        void onAnimationEnd(Animator animation);

        void onAnimationCancel(Animator animation);

        void onAnimationRepeat(Animator animation);

    }

    public static interface AnimatorPauseListener {

        void onAnimationPause(Animator animation);

        void onAnimationResume(Animator animation);

    }

    public void setAllowRunningAsynchronously(boolean mayRunAsync) {

        // It is up to subclasses to support this, if they can.

    }

    private static class AnimatorConstantState extends ConstantState<Animator> {

        final Animator mAnimator;

        int mChangingConf;

        public AnimatorConstantState(Animator animator) {

            mAnimator = animator;

            // ensure a reference back to here so that constante state is not gc'ed.

            mAnimator.mConstantState = this;

            mChangingConf = mAnimator.getChangingConfigurations();

        }

        @Override

        public int getChangingConfigurations() {

            return mChangingConf;

        }

        @Override

        public Animator newInstance() {

            final Animator clone = mAnimator.clone();

            clone.mConstantState = this;

            return clone;

        }

    }

}

通过看它的源码发现Animator是一个抽象类,既然它是抽象类,那么一定存在抽象的方法,现在就把几个抽象方法提出来

public abstract void setStartDelay(long startDelay); 这是延迟几秒开始执行动画

public abstract long getStartDelay();获取动画延迟执行的时间,单位为毫秒

 public abstract Animator setDuration(long duration); 设置动画执行的时间 单位为毫秒

 public abstract long getDuration();获取动画执行的时间

public abstract void setInterpolator(TimeInterpolator value);设置动画插值器

 public abstract boolean isRunning();动画是否在执行

下面是非抽象函数并且是空实现的

 public void start() {} 动画开始

  public void cancel() {}取消执行动画

public void end() {}结束动画执行

 public void setTarget(Object target) {}设置动画的标记

下面是非空实现方法：

public void pause() {}动画暂停的方法

public void resume() {}动画重新执行

public boolean isPaused() {}动画是否暂停了,默认返回值为false

public TimeInterpolator getInterpolator() {}  返回动画插值器对象,默认返回为null

public boolean isStarted() {} 动画是否执行了,默认返回值是调用了isRunning()方法,而这个方法又是抽象的,需要子类去实现,

public void addListener(AnimatorListener listener) {
if (mListeners == null) {
mListeners = new ArrayList<AnimatorListener>();
}
mListeners.add(listener);
}

这是添加动画监听的方法,它是用一个List集合去维护了所添加的监听器,而AnimatorListener是一个接口,如下：

public static interface AnimatorListener {
/**
* <p>Notifies the start of the animation.</p>
*
* @param animation The started animation.
*/
void onAnimationStart(Animator animation);

/**
* <p>Notifies the end of the animation. This callback is not invoked
* for animations with repeat count set to INFINITE.</p>
*
* @param animation The animation which reached its end.
*/
void onAnimationEnd(Animator animation);

/**
* <p>Notifies the cancellation of the animation. This callback is not invoked
* for animations with repeat count set to INFINITE.</p>
*
* @param animation The animation which was canceled.
*/
void onAnimationCancel(Animator animation);

/**
* <p>Notifies the repetition of the animation.</p>
*
* @param animation The animation which was repeated.
*/
void onAnimationRepeat(Animator animation);
}

这个接口分别定义了四个方法依次是动画开始,结束,取消,重复等回调接口,

public void removeListener(AnimatorListener listener) {
if (mListeners == null) {
return;
}
mListeners.remove(listener);
if (mListeners.size() == 0) {
mListeners = null;
}
}

这个是移除一个动画监听,

public ArrayList<AnimatorListener> getListeners() {
return mListeners;
}

这是获取所有监听动画

public void addPauseListener(AnimatorPauseListener listener) {
if (mPauseListeners == null) {
mPauseListeners = new ArrayList<AnimatorPauseListener>();
}
mPauseListeners.add(listener);
}

这是添加一个暂停动画监听的方法,而AnimatorPauseListener是一个接口

public static interface AnimatorPauseListener {
/**
* <p>Notifies that the animation was paused.</p>
*
* @param animation The animaton being paused.
* @see #pause()
*/
void onAnimationPause(Animator animation);

/**
* <p>Notifies that the animation was resumed, after being
* previously paused.</p>
*
* @param animation The animation being resumed.
* @see #resume()
*/
void onAnimationResume(Animator animation);
}

分别定义了动画暂停和重新执行的回调方法

public void removePauseListener(AnimatorPauseListener listener) {
if (mPauseListeners == null) {
return;
}
mPauseListeners.remove(listener);
if (mPauseListeners.size() == 0) {
mPauseListeners = null;
}
}

这是移除一个暂停动画的监听

public void removeAllListeners() {
if (mListeners != null) {
mListeners.clear();
mListeners = null;
}
if (mPauseListeners != null) {
mPauseListeners.clear();
mPauseListeners = null;
}
}

这是移除所有动画的监听,包括动画开始和结束的监听和暂停的监听

下面就开始讲ValueAnimator类的一些使用了,

public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ValueAnimator animator = ValueAnimator.ofInt(0,100);
animator.setDuration(1000);
animator.start();
}
}

这是一个平移动画,但我并没有把这个动画作用于某一个控件上,那这个动画到底有没有执行呢?我们知道动画都有监听的方法,

animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int curValue = (int)animation.getAnimatedValue();
Log.d(TAG,"curValue:"+curValue);
}
});

animation.getAnimatedValue()方法是返回动画的属性值,默认返回值是Object,但是我们传入的是int值,所以就可以强转成int值了,通过打印的log分析：

07-10 05:05:24.945 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:0

07-10 05:05:25.098 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:5

07-10 05:05:25.285 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:24

07-10 05:05:25.325 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:29

07-10 05:05:25.355 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:34

07-10 05:05:25.365 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:36

07-10 05:05:25.385 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:39

07-10 05:05:25.405 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:42

07-10 05:05:25.415 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:44

07-10 05:05:25.435 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:47

07-10 05:05:25.445 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:50

07-10 05:05:25.465 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:52

07-10 05:05:25.475 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:55

07-10 05:05:25.495 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:57

07-10 05:05:25.515 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:60

07-10 05:05:25.525 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:62

07-10 05:05:25.548 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:65

07-10 05:05:25.565 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:67

07-10 05:05:25.582 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:70

07-10 05:05:25.598 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:72

07-10 05:05:25.615 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:74

07-10 05:05:25.627 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:77

07-10 05:05:25.648 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:79

07-10 05:05:25.665 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:81

07-10 05:05:25.676 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:83

07-10 05:05:25.698 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:85

07-10 05:05:25.715 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:87

07-10 05:05:25.732 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:88

07-10 05:05:25.748 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:90

07-10 05:05:25.765 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:91

07-10 05:05:25.777 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:93

07-10 05:05:25.798 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:94

07-10 05:05:25.815 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:95

07-10 05:05:25.825 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:96

07-10 05:05:25.848 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:97

07-10 05:05:25.865 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:98

07-10 05:05:25.882 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:98

07-10 05:05:25.898 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:99

07-10 05:05:25.915 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:99

07-10 05:05:25.927 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:99

07-10 05:05:25.948 1178-1178/com.example.valueanimatordemo D/MainActivity: curValue:100

通过上面的log知道,上面是打印的在1秒时间内所改变的值,从这个log就证明动画是执行了的,但是并没有作用于某一个控件上,从这就明显看出来和Tween动画的区别,现在就根据这些值做一个平移的动画,你会发现view类并没有什么方法设置可以执行属性动画的方法,那我们只能根据view提供的并外一个方法layout动态改变他在父view上的位置了,这个方法大家很熟悉了,

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<Button
android:id="@+id/btn_start_anim"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开始动画"
android:layout_alignParentRight="true"
/>
<ImageView
android:id="@+id/iv_show_grid"
android:layout_width="100px"
android:layout_height="100px"
android:src="@mipmap/grid"
/>
</RelativeLayout>

这个imageview显示的图片是胡歌的前女友,只能说明星真会玩,玩了就不玩了,

public class MainActivity extends Activity {
private static final String TAG = "MainActivity";
private Button btn_start_anim;
private ImageView iv_show_grid;
private int left,top;
private boolean isFirst;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_start_anim = (Button) findViewById(R.id.btn_start_anim);
iv_show_grid = (ImageView) findViewById(R.id.iv_show_grid);
btn_start_anim.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
execAnimator();
}
});
iv_show_grid.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(),"客官点我",Toast.LENGTH_SHORT).show();
}
});
}
private int tempValue = 0;
public void execAnimator(){
ValueAnimator animator = ValueAnimator.ofInt(0,100);
animator.setDuration(1000);
animator.start();
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int curValue = (int)animation.getAnimatedValue();
left = iv_show_grid.getLeft();
top = iv_show_grid.getTop();
iv_show_grid.layout(left+curValue-tempValue,top+curValue-tempValue,left+iv_show_grid.getWidth()+curValue-tempValue,iv_show_grid.getHeight()+curValue+top-tempValue);
tempValue = curValue;
}
});
}
}

效果：



ok,现在发现属性动画是不是能解决Tween动画的交互上的bug,imageview平移后点击是ok,

上面使用了ValueAnimator类的一个ofInt()方法,上面我们ofInt()方法传入了0,100表示从0变化到100,别以为ofInt()方法只接受2个参数,其实它是可变参数的,

public static ValueAnimator ofInt(int... values) {
ValueAnimator anim = new ValueAnimator();
anim.setIntValues(values);
return anim;
}

那我们可以利用方法实现类似上下移动的效果,

private int tempValue = 0;
public void execAnimator(){
ValueAnimator animator = ValueAnimator.ofInt(0,200,200,0,0,200,200,0,0,200,200,0);
animator.setDuration(1000);
animator.start();
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int curValue = (int)animation.getAnimatedValue();
left = iv_show_grid.getLeft();
top = iv_show_grid.getTop();
iv_show_grid.layout(left,top+curValue-tempValue,left+iv_show_grid.getWidth(),iv_show_grid.getHeight()+curValue+top-tempValue);
tempValue = curValue;
}
});
}

效果：



是不是感觉设置了动画的重复方法,其实并没有,

还有一个ofFloat方法其实和ofInt()方法功能是一样的,只是精度不一样而已,现在再玩一个方法,就是关于颜色变化的，

public static ValueAnimator ofArgb(int... values) {
ValueAnimator anim = new ValueAnimator();
anim.setIntValues(values);
anim.setEvaluator(ArgbEvaluator.getInstance());
return anim;
}

突然这个api是要到21才能用,关键是我现在最低版本是15,算了不改了,讲下另外一个方法,也是很重要的,就是插值器,

public void setInterpolator(TimeInterpolator value) {
if (value != null) {
mInterpolator = value;
} else {
mInterpolator = new LinearInterpolator();
}
}

发现我们没有设置的时候,默认是使用LinearInterpolator,先看下TimeInterpolator这个类,

public interface TimeInterpolator {

/**
* Maps a value representing the elapsed fraction of an animation to a value that represents
* the interpolated fraction. This interpolated value is then multiplied by the change in
* value of an animation to derive the animated value at the current elapsed animation time.
*
* @param input A value between 0 and 1.0 indicating our current point
*        in the animation where 0 represents the start and 1.0 represents
*        the end
* @return The interpolation value. This value can be more than 1.0 for
*         interpolators which overshoot their targets, or less than 0 for
*         interpolators that undershoot their targets.
*/
float getInterpolation(float input);
}

就一个方法getInterpolation()该方法一个形参input,从方法的注释上看到这个input的取值范围为[0,1],它有如下子类



我们现在可以自定义一个LinearInterpolator,通过log打印出input的值

class MyLinearInterpolator extends LinearInterpolator{
@Override
public float getInterpolation(float input) {
Log.e(TAG,"input="+input);
return super.getInterpolation(input);
}
}

设置插值器

animator.setInterpolator(new MyLinearInterpolator());

log:

07-10 09:12:10.701 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.0

07-10 09:12:10.710 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.0

07-10 09:12:10.730 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.017

07-10 09:12:10.760 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.05

07-10 09:12:10.781 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.067

07-10 09:12:10.792 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.083

07-10 09:12:10.820 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.1

07-10 09:12:10.831 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.117

07-10 09:12:10.851 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.133

07-10 09:12:10.881 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.167

07-10 09:12:10.901 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.183

07-10 09:12:10.921 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.2

07-10 09:12:10.941 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.233

07-10 09:12:10.970 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.25

07-10 09:12:10.981 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.267

07-10 09:12:11.010 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.3

07-10 09:12:11.030 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.317

07-10 09:12:11.050 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.333

07-10 09:12:11.071 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.35

07-10 09:12:11.092 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.367

07-10 09:12:11.111 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.4

07-10 09:12:11.131 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.417

07-10 09:12:11.141 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.433

07-10 09:12:11.160 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.45

07-10 09:12:11.190 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.467

07-10 09:12:11.200 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.483

07-10 09:12:11.220 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.5

07-10 09:12:11.230 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.517

07-10 09:12:11.251 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.533

07-10 09:12:11.260 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.55

07-10 09:12:11.271 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.567

07-10 09:12:11.301 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.583

07-10 09:12:11.310 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.6

07-10 09:12:11.330 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.617

07-10 09:12:11.340 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.633

07-10 09:12:11.370 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.667

07-10 09:12:11.410 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.7

07-10 09:12:11.450 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.733

07-10 09:12:11.480 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.767

07-10 09:12:11.490 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.783

07-10 09:12:11.520 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.8

07-10 09:12:11.531 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.817

07-10 09:12:11.551 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.833

07-10 09:12:11.560 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.85

07-10 09:12:11.580 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.867

07-10 09:12:11.620 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.9

07-10 09:12:11.650 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.933

07-10 09:12:11.690 3672-3672/com.example.valueanimatordemo E/MainActivity: input=0.967

07-10 09:12:11.710 3672-3672/com.example.valueanimatordemo E/MainActivity: input=1.0

通过上面的log也验证了input的取值范围是[0,1]

各个插值器的意思如下：

意义如下：
AccelerateDecelerateInterpolator   在动画开始与结束的地方速率改变比较慢，在中间的时候加速
AccelerateInterpolator                     在动画开始的地方速率改变比较慢，然后开始加速
AnticipateInterpolator                      开始的时候向后然后向前甩
AnticipateOvershootInterpolator     开始的时候向后然后向前甩一定值后返回最后的
BounceInterpolator                          动画结束的时候弹起
CycleInterpolator                             动画循环播放特定的次数，速率改变沿着正弦曲线
DecelerateInterpolator                    在动画开始的地方快然后慢
LinearInterpolator                            以常量速率改变
OvershootInterpolator                      向前甩一定值后再回到原来位置

现在每个插值器都玩下,看看效果：

共同的代码如下就是设置插值器代码不同而且

AccelerateDecelerateInterpolator   



AccelerateInterpolator 



AnticipateInterpolator 



AnticipateOvershootInterpolator  



BounceInterpolator 



CycleInterpolator 



DecelerateInterpolator 



OvershootInterpolator



LinearInterpolator



现在所有的动画插值器都演示了一边,可能有的不够明显,现在讲ValueAnimator类的

public void setEvaluator(TypeEvaluator value) {} 这个函数接受的形参是TypteEvaluator,

public interface TypeEvaluator<T> {

/**
* This function returns the result of linearly interpolating the start and end values, with
* <code>fraction</code> representing the proportion between the start and end values. The
* calculation is a simple parametric calculation: <code>result = x0 + t * (x1 - x0)</code>,
* where <code>x0</code> is <code>startValue</code>, <code>x1</code> is <code>endValue</code>,
* and <code>t</code> is <code>fraction</code>.
*
* @param fraction   The fraction from the starting to the ending values
* @param startValue The start value.
* @param endValue   The end value.
* @return A linear interpolation between the start and end values, given the
*         <code>fraction</code> parameter.
*/
public T evaluate(float fraction, T startValue, T endValue);

}

形参说明

fraction:从开始值startValue到endValue之间的值

startValue:开始值

endValue:结束值

现在看下TypeEvalator的一些实现类



从子类的名字就可以看出假如传入的是int值,那么就对应IntEvaluator类,

现在自定义一个IntEvaluator,看看evaluator方法中的三个参数：

/**
* 设置动画执行
*/
public void execAnimator(){
ValueAnimator animator = ValueAnimator.ofInt(0,200);
animator.setDuration(1000);
animator.setEvaluator(new MyIntEvaluator());
animator.start();
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int curValue = (int)animation.getAnimatedValue();
left = iv_show_grid.getLeft();
top = iv_show_grid.getTop();
iv_show_grid.layout(left,top+curValue-tempValue,left+iv_show_grid.getWidth(),iv_show_grid.getHeight()+curValue+top-tempValue);
tempValue = curValue;
}
});
}
class MyIntEvaluator extends IntEvaluator{
@Override
public Integer evaluate(float fraction, Integer startValue, Integer endValue) {
Log.e(TAG,"fraction="+fraction);
Log.e(TAG,"startValue="+fraction);
Log.e(TAG,"endValue="+endValue);
Log.e(TAG,"结果值="+super.evaluate(fraction, startValue, endValue));
return super.evaluate(fraction, startValue, endValue);
}
}

log:

07-10 14:06:53.232 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.0

07-10 14:06:53.232 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.0

07-10 14:06:53.242 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.242 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=0

07-10 14:06:53.255 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.0

07-10 14:06:53.255 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.0

07-10 14:06:53.255 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.255 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=0

07-10 14:06:53.272 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=7.1290135E-4

07-10 14:06:53.272 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=7.1290135E-4

07-10 14:06:53.272 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.282 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=0

07-10 14:06:53.305 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.0061558187

07-10 14:06:53.305 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.0061558187

07-10 14:06:53.305 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.305 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=1

07-10 14:06:53.342 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.017309189

07-10 14:06:53.342 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.017309189

07-10 14:06:53.342 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.342 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=3

07-10 14:06:53.362 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.02447176

07-10 14:06:53.362 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.02447176

07-10 14:06:53.372 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.372 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=4

07-10 14:06:53.402 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.043654233

07-10 14:06:53.402 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.043654233

07-10 14:06:53.402 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.412 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=8

07-10 14:06:53.442 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.06724939

07-10 14:06:53.442 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.06724939

07-10 14:06:53.442 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.442 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=13

07-10 14:06:53.462 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.09549156

07-10 14:06:53.462 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.09549156

07-10 14:06:53.482 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.482 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=19

07-10 14:06:53.533 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.16582394

07-10 14:06:53.533 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.16582394

07-10 14:06:53.533 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.533 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=33

07-10 14:06:53.562 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.20610732

07-10 14:06:53.562 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.20610732

07-10 14:06:53.562 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.562 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=41

07-10 14:06:53.602 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.27300477

07-10 14:06:53.602 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.27300477

07-10 14:06:53.612 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.622 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=54

07-10 14:06:53.631 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.32179415

07-10 14:06:53.631 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.32179415

07-10 14:06:53.642 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.642 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=64

07-10 14:06:53.662 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.34549147

07-10 14:06:53.662 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.34549147

07-10 14:06:53.693 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.693 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=69

07-10 14:06:53.772 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.5

07-10 14:06:53.772 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.5

07-10 14:06:53.793 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.802 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=100

07-10 14:06:53.822 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.6044678

07-10 14:06:53.832 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.6044678

07-10 14:06:53.832 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.832 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=120

07-10 14:06:53.862 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.65450853

07-10 14:06:53.862 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.65450853

07-10 14:06:53.862 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.872 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=130

07-10 14:06:53.902 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.7269952

07-10 14:06:53.932 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.7269952

07-10 14:06:53.932 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.932 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=145

07-10 14:06:53.962 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.7938927

07-10 14:06:53.972 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.7938927

07-10 14:06:53.982 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:53.992 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=158

07-10 14:06:54.022 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.8719225

07-10 14:06:54.033 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.8719225

07-10 14:06:54.033 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.033 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=174

07-10 14:06:54.062 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.9045085

07-10 14:06:54.062 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.9045085

07-10 14:06:54.062 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.062 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=180

07-10 14:06:54.072 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.91962016

07-10 14:06:54.082 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.91962016

07-10 14:06:54.082 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.093 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=183

07-10 14:06:54.134 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.9671645

07-10 14:06:54.134 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.9671645

07-10 14:06:54.142 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.142 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=193

07-10 14:06:54.175 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.98309815

07-10 14:06:54.182 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.98309815

07-10 14:06:54.192 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.212 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=196

07-10 14:06:54.222 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.9973154

07-10 14:06:54.222 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.9973154

07-10 14:06:54.232 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.232 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=199

07-10 14:06:54.252 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.9993685

07-10 14:06:54.262 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.9993685

07-10 14:06:54.262 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.272 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=199

07-10 14:06:54.292 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=1.0

07-10 14:06:54.292 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=1.0

07-10 14:06:54.292 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:06:54.322 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=200

从上面的log可以看出,endValue的值是不变的，也就是我们这行代码传入的第二个参数：

ValueAnimator animator = ValueAnimator.ofInt(0,200);

startValue的值是从0到1,fraction的值也是从0到1,这二个值其实相等的,只是fraction是float值,startValue值是int值,而结果值的计算公式为：

public Integer evaluate(float fraction, Integer startValue, Integer endValue) {
int startInt = startValue;
return (int)(startInt + fraction * (endValue - startInt));
}

这是源码中已有的,我们就拿log中的一个值来计算

07-10 14:16:04.042 2128-2128/com.example.valueanimatordemo E/MainActivity: fraction=0.11175674

07-10 14:16:04.052 2128-2128/com.example.valueanimatordemo E/MainActivity: startValue=0.11175674

07-10 14:16:04.052 2128-2128/com.example.valueanimatordemo E/MainActivity: endValue=200

07-10 14:16:04.052 2128-2128/com.example.valueanimatordemo E/MainActivity: 结果值=22

0.11175674+0.11175674*(200-0.11175674)=0.11175674*(1+200-0.11175674)=22.450613055062455
但是结果是Integer，所以结果就是22了

在这补充一个知识点：

ValueAnimator
animator = ValueAnimator.ofInt(100,200); 这个100是要执行动画的起始坐标,200是动画结束时的坐标,这个是以父view的左上角为参考点，

下面我们重写evaluate()方法的返回值看看结果是什么样的：

class MyIntEvaluator extends IntEvaluator{
@Override
public Integer evaluate(float fraction, Integer startValue, Integer endValue) {
int temp=(int)fraction;
int startInt= startValue;
return (int)(100+startInt + fraction * (endValue - startInt));
}
}

效果：



其实这个不看效果,也知道肯定比传入的200(最终坐标)要大,现在看一个以后会经常使用的一个类就是ArgbEvaluator，

/**
* 设置动画执行
*/
public void execAnimator(){
ValueAnimator animator = ValueAnimator.ofInt(0xffffff00,0xffffff99);
animator.setEvaluator(new ArgbEvaluator());
animator.setDuration(5000);

animator.setEvaluator(new ArgbEvaluator());
animator.start();
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int curValue = (int)animation.getAnimatedValue();
btn_argb.setBackgroundColor(curValue);
}
});
}

效果：



ValueAnimator类还有一个可以自定义对象的方法就是ofObject()，看源码：

public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) {
ValueAnimator anim = new ValueAnimator();
anim.setObjectValues(values);
anim.setEvaluator(evaluator);
return anim;
}

参数说明：

evaluator:这个是你自定义的TypeEvaluator

values:是你对这个自定义对象的值的变化

之前的博客记得写过什么水波纹类似的效果,其实就是在时间很短的情况下改变圆的半径实现的,今天也用这个也实现下这个效果

public class CustomView extends View {
private static final String TAG ="CustomView" ;
private Paint mPaint;
private MyPoint myPoint;
public CustomView(Context context) {
super(context);
}

public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mPaint.setStrokeWidth(5);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setColor(Color.WHITE);
}

public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(myPoint!=null){
Log.e(TAG,"第一次他的半径是==="+myPoint.getRaduis());
canvas.drawCircle(200, 200, myPoint.getRaduis(), mPaint);
}
}
public void execAnimator() {
ValueAnimator animator = ValueAnimator.ofObject(new RadiusEvaluator(), new MyPoint(10), new MyPoint(200));
animator.setDuration(100);
animator.setRepeatCount(10);
animator.start();
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
myPoint = (MyPoint)animation.getAnimatedValue();
invalidate();
}
});
}
}

自定义半径类：

public class MyPoint {

private int raduis;

public MyPoint(int raduis) {
this.raduis = raduis;
}

public int getRaduis() {
return raduis;
}
public void setRaduis(int raduis) {
this.raduis = raduis;
}
}

自定义TypeEaluator

public class RadiusEvaluator implements TypeEvaluator<MyPoint> {
@Override
public MyPoint evaluate(float fraction, MyPoint startValue, MyPoint endValue) {
int startRaduis = startValue.getRaduis();
int endRaduis  = endValue.getRaduis();
int curValue = (int)(startRaduis + fraction * (endRaduis - startRaduis));
return new MyPoint(curValue);
}
}

最后就是按钮点击执行动画了

btn_start_anim.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
customview.execAnimator();
}
});

效果：



现在我向动画中添加一个插值器BounceInterpolator,这个表示动画结束的时候弹起,而且要把动画时间放长点才好看出来效果：

public void execAnimator() {
ValueAnimator animator = ValueAnimator.ofObject(new RadiusEvaluator(), new MyPoint(10), new MyPoint(100));
animator.setDuration(1000);
animator.setInterpolator(new BounceInterpolator());
animator.start();
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
myPoint = (MyPoint)animation.getAnimatedValue();
invalidate();
}
});
}

效果：



ValueAnimator类基本的使用都讲完了,你发现使用ValueAnimator做view平移的时候是用view的layout()方法实现的,而ValueAnimator类并没有给我们直接提供方法让我们自己调用,那么就引人了ObjectAnimator这个类了,

ObjectAnimator是继承自ValueAnimator,所以ObjectAnimator类中的方法很多是继承了ValueAnimator中的方法,但是也对一些方法做了重写,比如ofInt()方法:

ValueAnimator类的ofInt()方法源码：

public static ValueAnimator ofInt(int... values) {
ValueAnimator anim = new ValueAnimator();
anim.setIntValues(values);
return anim;
}

ObjectAnimator中的ofInt()方法

public static ObjectAnimator ofInt(Object target, String propertyName, int... values) {
ObjectAnimator anim = new ObjectAnimator(target, propertyName);
anim.setIntValues(values);
return anim;
}

从源码就明显看的出来ofInt()方法不同,现在解释下ObjectAnimator类的ofInt()方法

public static ObjectAnimator ofInt(Object target, String propertyName, int... values) {}

参数说明：

Object target:作用于那个view,这个target就是那个view对象

String propertyName：作用于view上那个属性，

int...values:可变参数,也就是要对第二个参数(view属性)进行动画时传递的值

这三个参数中第一个和第三个参数都好理解,那么第二个参数是view的属性名是指啥,进入到View的源码中找出这几个函数：

public void setAlpha(@FloatRange(from=0.0, to=1.0) float alpha) {}

public void setRotation(float rotation) {}

public void setRotationX(float rotationX) {}

public void setRotationY(float rotationY) {}

public void setTranslationX(float translationX) {}

public void setTranslationY(float translationY) {}

public void setTranslationZ(float translationZ) {}

public void setScaleX(float scaleX) {}

public void setScaleY(float scaleY) {}

上面是View中的关于动画的几个set方法,我们看出来set函数都有一个形参,而ObjectAnimator中的ofInt()方法中第二个参数propertyName就是上面几个set函数中的形参,比如rotationX,translationX,scaleX,alpha,现在每个函数做一个简单的演示：

setAlpha():

public class MainActivity extends AppCompatActivity {
private Button btn_start_anim;
private TextView tv_show_anim;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv_show_anim = (TextView) findViewById(R.id.tv_show_anim);
btn_start_anim = (Button) findViewById(R.id.btn_start_anim);
btn_start_anim.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
execAnimator();
}
});
}
public void execAnimator(){
ObjectAnimator objectAnimator =  ObjectAnimator.ofFloat(tv_show_anim,"alpha",0,1,1,0,0,1,1,0);
objectAnimator.setDuration(2000);
objectAnimator.start();
}
}

效果：



setScaleX()

public void execAnimator(){
ObjectAnimator objectAnimator =  ObjectAnimator.ofFloat(tv_show_anim,"scaleX",1,3);
objectAnimator.setDuration(200);
objectAnimator.start();
}

效果：



setTranslationY()

public void execAnimator(){
ObjectAnimator objectAnimator =  ObjectAnimator.ofFloat(tv_show_anim,"translationY",0,300);
objectAnimator.setDuration(200);
objectAnimator.start();
}

效果：



setRotationX()

public void execAnimator(){

ObjectAnimator objectAnimator =  ObjectAnimator.ofFloat(tv_show_anim,"rotationX",0,180,180,0,0,180);

objectAnimator.setDuration(2000); objectAnimator.start();}
效果：



在这要讲一个可能会被忽略的问题就是我们每个view都有的一个方法就是设置背景

public void setBackgroundColor(@ColorInt int color){} 发现它接受的是一个int形参,如果要对这个属性进行动画的话,是不是属性名字就为color呢?答案是错的,属性名是：BackgroundColor

public void execAnimator(){

ObjectAnimator objectAnimator = ObjectAnimator.ofInt(tv_show_anim, "BackgroundColor", 0xffffffff, 0xffffff00, 0xff00ffff);

objectAnimator.setDuration(5000); objectAnimator.setRepeatCount(5); objectAnimator.setEvaluator(new ArgbEvaluator()); objectAnimator.start();}
效果：



前面都是单独的一个动画，如果我想实现一个放大并且同时有透明度的动画,ObjectValueAnimator和ValueAnimator都没办法实现我这需求,针对这个问题google一些大神们已经帮我们想办法解决了,Google帮我们提供了AnimatorSet,这个类有2个重要的函数：

public void playTogether(Animator... items) {}

public void playSequentially(Animator... items) {}

上面二个方法可以从后一个单词中可以看的出来,together是一起的意思,sequence是顺序的意思,Sequentially是副词吧,表示按顺序
所以这二个方法意思就出来了

playTogether中的形参是一个可变参数,传递的是动画的父类,这就是所谓的多态,当然AnimatorSet还给我们提供了重载的方法就是传入的是动画集合,




现在写个例子

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<Button
android:id="@+id/btn_start_anim"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="执行动画"
/>
<Button
android:id="@+id/button1"
android:layout_width="70dp"
android:layout_height="35dp"
android:text="按钮1"
android:layout_marginTop="40dp"
android:background="#FFBBFF"
/>
<Button
android:id="@+id/button2"
android:layout_width="70dp"
android:layout_height="35dp"
android:text="按钮2"
android:layout_marginTop="40dp"
android:layout_toRightOf="@id/button1"
android:layout_marginLeft="10dp"
android:layout_alignParentBottom="true"
android:background="#FF8247"
/>
<Button
android:id="@+id/button3"
android:layout_width="70dp"
android:layout_height="35dp"
android:text="按钮3"
android:layout_marginTop="40dp"
android:layout_toRightOf="@id/button2"
android:layout_marginLeft="10dp"
android:background="#CD2990"
/>
</RelativeLayout>

MainActivity类

public class MainActivity extends AppCompatActivity {
private Button btn_start_anim,button1,button2,button3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

btn_start_anim = (Button) findViewById(R.id.btn_start_anim);
button1 = (Button) findViewById(R.id.button1);
button2 = (Button) findViewById(R.id.button2);
button3 = (Button) findViewById(R.id.button3);

btn_start_anim.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
execAnimator();
}
});

}
private void execAnimator() {
ObjectAnimator objectAnimator1 = ObjectAnimator.ofFloat(button1, "translationY",60,400);
ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(button2, "translationY", 0, -400);
ObjectAnimator objectAnimator3 = ObjectAnimator.ofFloat(button3, "translationY", 60, 400);

AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playSequentially(objectAnimator1,objectAnimator2,objectAnimator3);
animatorSet.setDuration(2000);
animatorSet.start();
}
}

效果：






从这效果中可以看出来AnimatorSet中的playSequentially()方法是按顺序(往AnimatorSet中添加的顺序)执行动画的,前一个动画执行完后,才播放下一个动画,现在我把playSequentially()改成playTogether()方法,看看效果：






很明显这三个动画是同时执行的,现在我需要实现一个可以循环执行的动画需求,但是你发现AnimatorSet中并没有给我们提供这种方法,那么自己能不能实现呢?
YES

private void execAnimator() {
ObjectAnimator objectAnimator1 = ObjectAnimator.ofFloat(button1, "translationY",60,400);
objectAnimator1.setRepeatCount(ValueAnimator.INFINITE);
ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(button2, "translationY", 0, -400);
objectAnimator2.setRepeatCount(ValueAnimator.INFINITE);
ObjectAnimator objectAnimator3 = ObjectAnimator.ofFloat(button3, "translationY", 60, 400);
objectAnimator3.setRepeatCount(ValueAnimator.INFINITE);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playTogether(objectAnimator1,objectAnimator2,objectAnimator3);
animatorSet.setDuration(2000);
animatorSet.start();
}

效果：



再来玩一个动画就下班

private void execAnimator() {
ObjectAnimator objectAnimator1 = ObjectAnimator.ofFloat(iv_ball, "translationY",0,590);
ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(iv_ball, "translationX", 0, 380);
ObjectAnimator objectAnimator3 = ObjectAnimator.ofFloat(iv_ball, "translationY", 590, 0);
ObjectAnimator objectAnimator4 = ObjectAnimator.ofFloat(iv_ball, "translationX", 380, 0);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playSequentially(objectAnimator1,objectAnimator2,objectAnimator3,objectAnimator4);
animatorSet.setDuration(2000);
animatorSet.start();
}

这个x,y轴的值是我估测的,没有通过计算,懒的写!效果



现在有个问题就是AnimatorSet中有setDuration()方法,而单独的ObjectAnimator也有setDuration()设置动画执行的方法,那么最后以那个为标准呢?我写了例子演示下就知道了

public void execAnimator() {

ObjectAnimator objectAnimator1 = ObjectAnimator.ofFloat(button1, "translationY",0,600);
ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(button2, "translationY", 0, 600);
objectAnimator1.setDuration(1000);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playTogether(objectAnimator1,objectAnimator2);
animatorSet.setDuration(10000);
animatorSet.start();

}
效果：



从效果上看就知道最后是以AnimatorSet设置的时间为准,

总结：在设置多个动画一起执行的时候,最后以AnimatorSet设置的时间为标准