效果如下：

主要代码如下：

public static Bitmap createReflectedImage(Bitmap originalImage) {

final int reflectionGap = 4;

int width = originalImage.getWidth();

int height = originalImage.getHeight();

Matrix matrix = new Matrix();

matrix.preScale(1, -1);

Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,

height / 2, width, height / 2, matrix, false);

Bitmap bitmapWithReflection = Bitmap.createBitmap(width,

(height + height / 2), Config.ARGB_8888);

Canvas canvas = new Canvas(bitmapWithReflection);

canvas.drawBitmap(originalImage, 0, 0, null);

Paint defaultPaint = new Paint();

canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);

canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

Paint paint = new Paint();

LinearGradient shader = new LinearGradient(0,

originalImage.getHeight(), 0, bitmapWithReflection.getHeight()

+ reflectionGap, 0×70ffffff, 0×00ffffff,

TileMode.MIRROR);

paint.setShader(shader);

paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));

canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()

+ reflectionGap, paint);

return bitmapWithReflection;

}

解释一下：

Matrix matrix = new Matrix();

matrix.preScale(1, -1);

Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,

height / 2, width, height / 2, matrix, false);

创建反转后的图片Bitmap对象，图片高是原图的一半。

Bitmap bitmapWithReflection = Bitmap.createBitmap(width,

(height + height / 2), Config.ARGB_8888);

创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍。

Canvas canvas = new Canvas(bitmapWithReflection);

canvas.drawBitmap(originalImage, 0, 0, null);

创建画布对象，将原图画于画布，起点是原点位置。

Paint defaultPaint = new Paint();

canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);

canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

将反转后的图片画到画布中。

LinearGradient shader = new LinearGradient(0,

originalImage.getHeight(), 0, bitmapWithReflection.getHeight()

+ reflectionGap, 0×70ffffff, 0×00ffffff,

创建线性渐变LinearGradient 对象。

canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()

+ reflectionGap, paint);

画布画出反转图片大小区域，然后把渐变效果加到其中，就出现了图片的倒影效果。