android 手势检测

android提供了手势检测，并为手势检测提供了相应的监听器

手势检测的类GestureDetector

那么现在我们使用手势检测实现一个小demo ，相当于简单的一个图片浏览器

其实非常简单，首先是XML布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.zking.g150715_android21_gesture.MainActivity">
<ViewFlipper
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/vf_main_image"
>
</ViewFlipper>
</LinearLayout>

那么接下来就是java文件

其中相应的方法我在代码中打了注释，一共有6个方法，然后我添加了简单的动画效果，最后我会把动画文件发上来，借鉴就好

package com.zking.g150715_android21_gesture;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ImageView;
import android.widget.Toast;
import android.widget.ViewFlipper;

public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener{

private ViewFlipper vf_main_image;
private int images[]={R.drawable.s1,R.drawable.s2,R.drawable.s3};
private GestureDetector gesture;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
vf_main_image = (ViewFlipper) findViewById(R.id.vf_main_image);

//给ViewFilpper设置适配器(不能)
for (int i = 0; i < images.length; i++) {
ImageView iv=new ImageView(this);
iv.setImageResource(images[i]);
vf_main_image.addView(iv);
}
//实例化一个手势检测器的类
gesture = new GestureDetector(this,this);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
return gesture.onTouchEvent(event);
}

@Override
public boolean onDown(MotionEvent motionEvent) {
Log.i("test","按下");
return false;
}

@Override
public void onShowPress(MotionEvent motionEvent) {
Log.i("test","按下，按下但是还没有开始移动");
}

@Override
public boolean onSingleTapUp(MotionEvent motionEvent) {
Log.i("test","按一下");
return false;
}

@Override
public boolean onScroll(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {
Log.i("test","滑动");
return false;
}

@Override
public void onLongPress(MotionEvent motionEvent) {
Log.i("test","长按");
}

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float v, float v1) {
if(e1.getX()-e2.getX()>=200){
Toast.makeText(MainActivity.this, "←←←←←", Toast.LENGTH_SHORT).show();
vf_main_image.showNext();//下一张

//左出左进
vf_main_image.setOutAnimation(this,R.anim.left_out);
vf_main_image.setInAnimation(this,R.anim.left_in);

}else if(e2.getX()-e1.getX()>=200){
Toast.makeText(MainActivity.this, "→→→→→", Toast.LENGTH_SHORT).show();
vf_main_image.showPrevious();//上一张
//右出右进
vf_main_image.setOutAnimation(this,R.anim.right_out);
vf_main_image.setInAnimation(this,R.anim.right_in);
}
return false;
}
}

那么，到现在就实现了，右滑上一张的功能和左滑下一张的功能，最后是动画文件

左进动画

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:fillAfter="true"
>
<!--左进-->
<translate
android:fromXDelta="-100%p"
android:toXDelta="0"
>
</translate>
<rotate
android:fromDegrees="0"
android:toDegrees="360"
android:pivotY="50%"
android:pivotX="50%"
></rotate>

</set>

左出动画

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:fillAfter="true"
>
<!--左出-->
<translate
android:fromXDelta="0"
android:toXDelta="-100%p"
>
</translate>
<rotate
android:fromDegrees="0"
android:toDegrees="360"
android:pivotY="50%"
android:pivotX="50%"
></rotate>

</set>

右进动画

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:fillAfter="true"
>
<!--左出-->
<translate
android:fromXDelta="100%p"
android:toXDelta="0"
>
</translate>
<rotate
android:fromDegrees="0"
android:toDegrees="360"
android:pivotY="50%"
android:pivotX="50%"
></rotate>

</set>

右出动画

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:fillAfter="true"
>
<!--右出-->
<translate
android:fromXDelta="0"
android:toXDelta="100%p"
>
</translate>
<rotate
android:fromDegrees="0"
android:toDegrees="360"
android:pivotY="50%"
android:pivotX="50%"
></rotate>

</set>