android 创建一个图片的倒影

算是一个比较实用的东西喽，直接上函数。。：）

public static Bitmap createReflectionImage(Bitmap bitmap) {

        int width = bitmap.getWidth();
        int height = bitmap.getHeight();

        Matrix matrix = new Matrix();
        matrix.preScale(1, -1);

        Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, false);
        Bitmap newBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);

        Canvas canvas = new Canvas(newBitmap);
        canvas.drawBitmap(reflectionImage, 0, 0, null);

        Paint paint = new Paint();
        LinearGradient shader = new LinearGradient(0, 0, 0, height, 0xacffffff, 0x00ffffff,
                TileMode.CLAMP);
        paint.setShader(shader);
        // Set the Transfer mode to be porter duff and destination in
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        // Draw a rectangle using the paint with our linear gradient
        canvas.drawRect(0, 0, width, height, paint);

        return newBitmap;
    }

（整一篇先充充数，嘿嘿。）