效果如下：
<ignore_js_op>
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;
- }
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解释一下：
- Matrix matrix = new Matrix();
- matrix.preScale(1, -1);
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实现图片的反转，见Android利用Matrix简单处理图片。
- Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
- height / 2, width,
height / 2, matrix, false);
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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);
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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);
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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);
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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,
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创建线性渐变LinearGradient
对象。
- canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
- + reflectionGap,
paint);
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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。
Android开发：轻松实现图片倒影效果
原文：http://www.cnblogs.com/xiaochao1234/p/3530824.html
