xml-------布局-----------------------------------

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:id="@+id/plus"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="增大透明度"
            />
        <Button
            android:id="@+id/minus"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="降低透明度"
            />
        <Button
            android:id="@+id/next"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="下一张"
            />
    </LinearLayout>

<ImageView
    android:id="@+id/image1"
    android:layout_width="wrap_content"
    android:layout_height="280dp"
    android:src="http://www.mamicode.com/@drawable/img3"
    android:scaleType="fitCenter"/>
<ImageView
    android:id="@+id/image2"
    android:layout_width="120dp"
    android:layout_height="120dp"
    android:background="#00f"
    android:layout_margin="10dp"/>
</LinearLayout>




MainActivity.java-----------------Java调用----------------------------------

  int[] images=new int[]{
          R.drawable.img1,
          R.drawable.img2,
          R.drawable.img3,
          R.drawable.img4,
          R.drawable.img5,

  };
  int currentIMG=2;
  private int alpha=255;
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.imageviewer);
      final Button plus=(Button) findViewById(R.id.plus);
      final Button minus=(Button) findViewById(R.id.minus);
      final ImageView image1=(ImageView) findViewById(R.id.image1);
      final ImageView image2=(ImageView) findViewById(R.id.image2);
      final Button next=(Button) findViewById(R.id.next);
      next.setOnClickListener(new View.OnClickListener(){
          @Override
          public void onClick(View v) {
              image1.setImageResource(images[++currentIMG%images.length]);
          }
      });
     View.OnClickListener listener=new View.OnClickListener(){
         @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
         @Override
         public void onClick(View v){
             if(v==plus){
                 alpha+=20;
             }
             if(v==minus){
                 alpha-=20;
             }
             if(alpha>=255){
                 alpha=255;
             }
             if(alpha<=0){
                 alpha=0;
             }
             image1.setImageAlpha(alpha);
         }
     };

      plus.setOnClickListener(listener);
      minus.setOnClickListener(listener);
image1.setOnTouchListener(new View.OnTouchListener() {
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        BitmapDrawable bitmapDrawable=(BitmapDrawable) image1.getDrawable();
        Bitmap bitmap=bitmapDrawable.getBitmap();
        double scale=1.0*bitmap.getHeight()/image1.getHeight();
        int x=(int)  (event.getX()*scale);
        int y=(int) (event.getY()*scale);
        if(x+120>bitmap.getWidth()){
            x=bitmap.getWidth()-120;
        }
        if(y+120>bitmap.getHeight()){
            y=bitmap.getHeight()-120;
        }
        image2.setImageBitmap(Bitmap.createBitmap(bitmap,x,y,120,120));
        image2.setImageAlpha(alpha);
        return false;
    }
});
  }

强大的图片浏览器---------增强、降低透明度、切换下一张