/*实现图片倒影(tested)*/  public class ButtonImageActivity extends Activity {      /** Called when the activity is first created. */      private ImageView image_btn;      @Override      public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.main);          image_btn=(ImageView)findViewById(R.id.image_btn);          Bitmap bitmap =((BitmapDrawable)getResources().getDrawable(R.drawable.image_btn)).getBitmap();          image_btn.setImageBitmap(createReflectedImage(bitmap));          image_btn.setOnClickListener(new OnClickListener() {                              public void onClick(View v) {                  // TODO Auto-generated method stub                                  }          });      }      private Bitmap createReflectedImage(Bitmap originalBitmap) {           // 图片与倒影间隔距离           final int reflectionGap = 4;                         // 图片的宽度           int width = originalBitmap.getWidth();           // 图片的高度           int height = originalBitmap.getHeight();                         Matrix matrix = new Matrix();           // 图片缩放，x轴变为原来的1倍，y轴为-1倍,实现图片的反转           matrix.preScale(1, -1);           // 创建反转后的图片Bitmap对象，图片高是原图的一半。           Bitmap reflectionBitmap = Bitmap.createBitmap(originalBitmap, 0,                   height / 2, width, height / 2, matrix, false);           // 创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍。           Bitmap withReflectionBitmap = Bitmap.createBitmap(width, (height                   + height / 2 + reflectionGap), Config.ARGB_8888);                 // 构造函数传入Bitmap对象，为了在图片上画图           Canvas canvas = new Canvas(withReflectionBitmap);           // 画原始图片           canvas.drawBitmap(originalBitmap, 0, 0, null);                 // 画间隔矩形           Paint defaultPaint = new Paint();           canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);                 // 画倒影图片           canvas.drawBitmap(reflectionBitmap, 0, height + reflectionGap, null);                 // 实现倒影效果           Paint paint = new Paint();           LinearGradient shader = new LinearGradient(0, originalBitmap.getHeight(),                    0, withReflectionBitmap.getHeight(), 0x70ffffff, 0x00ffffff,                   TileMode.MIRROR);           paint.setShader(shader);           paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));                 // 覆盖效果           canvas.drawRect(0, height, width, withReflectionBitmap.getHeight(), paint);                 return withReflectionBitmap;       }   }