android 中viewpager+fragment仿微信底部TAG完美渐变

viewpager+fragment仿微信底部TAG完美渐变，在图片渐变的同时字的颜色也在变，注意，是渐变哦！

效果图：

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:zhy="http://schemas.android.com/apk/res/com.Sing.weixin"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<android.support.v4.view.ViewPager
android:id="@+id/id_viewpager"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
</android.support.v4.view.ViewPager>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="60dp"
android:background="@drawable/tabbg"
android:orientation="horizontal" >
<com.Sing.weixin.ChangeColorIconWithTextView
android:id="@+id/id_indicator_one"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:padding="5dp"
zhy:icon="@drawable/ic_menu_start_conversation"
zhy:text="@string/tab_one"
zhy:text_size="12sp" />
<com.Sing.weixin.ChangeColorIconWithTextView
android:id="@+id/id_indicator_two"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:padding="5dp"
zhy:icon="@drawable/ic_menu_friendslist"
zhy:text="@string/tab_two"
zhy:text_size="12sp" />
</LinearLayout>
</LinearLayout>

MainActivity.java

package com.Sing.weixin;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewConfiguration;
@SuppressLint("NewApi")
public class MainActivity extends FragmentActivity implements
OnPageChangeListener, OnClickListener {
private ViewPager mViewPager;
// 选项卡一Fragment
private FrgReturnVisit returnVisit;
// 选项卡一Fragment
private FrgMicroVisit microVisit;
private List<ChangeColorIconWithTextView> mTabIndicator = new ArrayList<ChangeColorIconWithTextView>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setOverflowShowingAlways();
mViewPager = (ViewPager) findViewById(R.id.id_viewpager);
mViewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
initTabIndicator();
mViewPager.setOnPageChangeListener(this);
}
private void initTabIndicator() {
ChangeColorIconWithTextView one = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_one);
ChangeColorIconWithTextView two = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_two);
mTabIndicator.add(one);
mTabIndicator.add(two);
one.setOnClickListener(this);
two.setOnClickListener(this);
one.setIconAlpha(1.0f);
}
@Override
public void onPageSelected(int arg0) {
}
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
if (positionOffset > 0) {
ChangeColorIconWithTextView left = mTabIndicator.get(position);
ChangeColorIconWithTextView right = mTabIndicator.get(position + 1);
left.setIconAlpha(1 - positionOffset);
right.setIconAlpha(positionOffset);
}
}
@Override
public void onPageScrollStateChanged(int state) {
}
@Override
public void onClick(View v) {
resetOtherTabs();
switch (v.getId()) {
case R.id.id_indicator_one:
mTabIndicator.get(0).setIconAlpha(1.0f);
mViewPager.setCurrentItem(0, false);
break;
case R.id.id_indicator_two:
mTabIndicator.get(1).setIconAlpha(1.0f);
mViewPager.setCurrentItem(1, false);
break;
}
}
/**
* 重置其他的Tab
*/
private void resetOtherTabs() {
for (int i = 0; i < mTabIndicator.size(); i++) {
mTabIndicator.get(i).setIconAlpha(0);
}
}
private void setOverflowShowingAlways() {
try {
// true if a permanent menu key is present, false otherwise.
ViewConfiguration config = ViewConfiguration.get(this);
Field menuKeyField = ViewConfiguration.class.getDeclaredField("sHasPermanentMenuKey");
menuKeyField.setAccessible(true);
menuKeyField.setBoolean(config, false);
} catch (Exception e) {
e.printStackTrace();
}
}
public class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
private final String[] titles = { "选项一", "选项二"};
@Override
public CharSequence getPageTitle(int position) {
return titles[position];
}
@Override
public int getCount() {
return titles.length;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
if (returnVisit == null) {
returnVisit = new FrgReturnVisit();
}
return returnVisit;
case 1:
if (microVisit == null) {
microVisit = new FrgMicroVisit();
}
return microVisit;
default:
return null;
}
}
}
}

ChangeColorIconWithTextView.java

package com.Sing.weixin;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Looper;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
public class ChangeColorIconWithTextView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mPaint;
/**
* 颜色
*/
private int mColor = 0xFF45C01A;
/**
* 透明度 0.0-1.0
*/
private float mAlpha = 0f;
/**
* 图标
*/
private Bitmap mIconBitmap;
/**
* 限制绘制icon的范围
*/
private Rect mIconRect;
/**
* icon底部文本
*/
private String mText = "demo";
private int mTextSize = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 10, getResources().getDisplayMetrics());
private Paint mTextPaint;
private Rect mTextBound = new Rect();
public ChangeColorIconWithTextView(Context context) {
super(context);
}
/**
* 初始化自定义属性值
*
* @param context
* @param attrs
*/
public ChangeColorIconWithTextView(Context context, AttributeSet attrs) {
super(context, attrs);
// 获取设置的图标
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.ChangeColorIconView);
int n = a.getIndexCount();
for (int i = 0; i < n; i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.ChangeColorIconView_icon:
BitmapDrawable drawable = (BitmapDrawable) a.getDrawable(attr);
mIconBitmap = drawable.getBitmap();
break;
case R.styleable.ChangeColorIconView_color:
mColor = a.getColor(attr, 0x45C01A);
break;
case R.styleable.ChangeColorIconView_text:
mText = a.getString(attr);
break;
case R.styleable.ChangeColorIconView_text_size:
mTextSize = (int) a.getDimension(attr, TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_SP, 10,
getResources().getDisplayMetrics()));
break;
}
}
a.recycle();
mTextPaint = new Paint();
mTextPaint.setTextSize(mTextSize);
mTextPaint.setColor(0xff555555);
// 得到text绘制范围
mTextPaint.getTextBounds(mText, 0, mText.length(), mTextBound);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// 得到绘制icon的宽
int bitmapWidth = Math.min(getMeasuredWidth() - getPaddingLeft()
- getPaddingRight(), getMeasuredHeight() - getPaddingTop()
- getPaddingBottom() - mTextBound.height());
int left = getMeasuredWidth() / 2 - bitmapWidth / 2;
int top = (getMeasuredHeight() - mTextBound.height()) / 2 - bitmapWidth
/ 2;
// 设置icon的绘制范围
mIconRect = new Rect(left, top, left + bitmapWidth, top + bitmapWidth);
}
@Override
protected void onDraw(Canvas canvas) {
int alpha = (int) Math.ceil((255 * mAlpha));
canvas.drawBitmap(mIconBitmap, null, mIconRect, null);
setupTargetBitmap(alpha);
drawSourceText(canvas, alpha);
drawTargetText(canvas, alpha);
canvas.drawBitmap(mBitmap, 0, 0, null);
}
private void setupTargetBitmap(int alpha) {
mBitmap = Bitmap.createBitmap(getMeasuredWidth(), getMeasuredHeight(),
Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPaint = new Paint();
mPaint.setColor(mColor);
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setAlpha(alpha);
mCanvas.drawRect(mIconRect, mPaint);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setAlpha(255);
mCanvas.drawBitmap(mIconBitmap, null, mIconRect, mPaint);
}
private void drawSourceText(Canvas canvas, int alpha) {
mTextPaint.setTextSize(mTextSize);
mTextPaint.setColor(0xff333333);
mTextPaint.setAlpha(255 - alpha);
canvas.drawText(mText, mIconRect.left + mIconRect.width() / 2
- mTextBound.width() / 2,
mIconRect.bottom + mTextBound.height(), mTextPaint);
}
private void drawTargetText(Canvas canvas, int alpha) {
mTextPaint.setColor(mColor);
mTextPaint.setAlpha(alpha);
canvas.drawText(mText, mIconRect.left + mIconRect.width() / 2
- mTextBound.width() / 2,
mIconRect.bottom + mTextBound.height(), mTextPaint);
}
public void setIconAlpha(float alpha) {
this.mAlpha = alpha;
invalidateView();
}
private void invalidateView() {
if (Looper.getMainLooper() == Looper.myLooper()) {
invalidate();
} else {
postInvalidate();
}
}
public void setIconColor(int color) {
mColor = color;
}
public void setIcon(int resId) {
this.mIconBitmap = BitmapFactory.decodeResource(getResources(), resId);
if (mIconRect != null)
invalidateView();
}
public void setIcon(Bitmap iconBitmap) {
this.mIconBitmap = iconBitmap;
if (mIconRect != null)
invalidateView();
}
private static final String INSTANCE_STATE = "instance_state";
private static final String STATE_ALPHA = "state_alpha";
@Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(INSTANCE_STATE, super.onSaveInstanceState());
bundle.putFloat(STATE_ALPHA, mAlpha);
return bundle;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
mAlpha = bundle.getFloat(STATE_ALPHA);
super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_STATE));
} else {
super.onRestoreInstanceState(state);
}
}
}

github:https://github.com/ganchuanpu/Demo_Sing_weixin

以上所述是小编给大家介绍的android 中viewpager+fragment仿微信底部TAG完美渐变效果，希望对大家有所帮助！

您可能感兴趣的文章:

• Android中Activity和Fragment传递数据的两种方式
• Android中Fragment相互切换间不被回收的实现方法
• Android开发中如何解决Fragment +Viewpager滑动页面重复加载的问题
• Android使用TabLayout+Fragment实现顶部选项卡
• Android使用TabLayou+fragment+viewpager实现滑动切换页面效果
• Android 中ActionBar+fragment实现页面导航的实例