带有倒影的Gallery

带有倒影的图片滑动效果，注释非常详细。 部分代码如下： for (int imageId : mImageIds) { Bitmap originalImage = BitmapFactory.decodeResource(mContext .getResources(), imageId); int width = originalImage.getWidth(); int height = originalImage.getHeight(); //设置图片反转 Matrix matrix = new Matrix(); // matrix.setRotate(30); //缩放图片的动作。矩阵前乘 // 1表示放大比例，不放大也不缩小。 // -1表示在y轴上相反，即旋转180度。 matrix.preScale(1, -1); //reflectionImage就是下面那个透明的倒影，宽为图片本来的宽度，高是图片高度的一半 //从height/2的高度开始到高度为（height/2）+（height/4) Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height / 2, width, height / 4, matrix, false); //创建一个新的Bitmap高度为原来的1.5倍 Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 2), Config.ARGB_8888); //先画原始的图片 Canvas canvas = new Canvas(bitmapWithReflection); canvas.drawBitmap(originalImage, 0, 0, null); Paint deafaultPaint = new Paint(); // 抗锯齿的方法 // deafaultPaint.setAntiAlias(true); //画图片与倒影之间的间距 canvas.drawRect(0, height, width, height + reflectionGap, deafaultPaint); //画倒影 canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null); Paint paint = new Paint(); // 抗锯齿的方法 // paint.setAntiAlias(true); //创建一个渐变的模板放在下面被反转的图片上面 LinearGradient shader = new LinearGradient(0, originalImage.getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP); paint.setShader(shader); paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint); ImageView imageView = new ImageView(mContext); imageView.setImageBitmap(bitmapWithReflection); imageView.setLayoutParams(new GalleryFlow.LayoutParams(180, 240)); // imageView.setScaleType(ScaleType.MATRIX); mImages[index++] = imageView; } return true; }