/*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;

}

}