Android gallery 3D效果

在看了iOS上面的CoverFlow后，感觉效果真的不错，就想在android上面实现一个，这个程序在网上参考了一此核心的代码，当然我添加了一些其他的东西，废话不多话，先看效果，不然就是无图无真相了。

其实实现这个效果很简单，下面作一个简单的介绍

这个基本思路是：

1，创建一个源图一样的图，利用martrix将图片旋转180度。这个倒影图的高是源图的一半。

package com.lee.gallery3d.utils;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.Canvas;import android.graphics.LinearGradient;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.PixelFormat;import android.graphics.PorterDuffXfermode;import android.graphics.Shader.TileMode;import android.graphics.drawable.Drawable;public class BitmapUtil{    public static Bitmap createReflectedBitmap(Bitmap srcBitmap)    {        if (null == srcBitmap)        {            return null;        }                // The gap between the reflection bitmap and original bitmap.         final int REFLECTION_GAP = 4;                int srcWidth  = srcBitmap.getWidth();        int srcHeight = srcBitmap.getHeight();        int reflectionWidth  = srcBitmap.getWidth();        int reflectionHeight = srcBitmap.getHeight() / 2;                if (0 == srcWidth || srcHeight == 0)        {            return null;        }                // The matrix        Matrix matrix = new Matrix();        matrix.preScale(1, -1);                try        {            // The reflection bitmap, width is same with original's, height is half of original's.            Bitmap reflectionBitmap = Bitmap.createBitmap(                    srcBitmap,                    0,                     srcHeight / 2,                    srcWidth,                     srcHeight / 2,                    matrix,                    false);                        if (null == reflectionBitmap)            {                return null;            }                        // Create the bitmap which contains original and reflection bitmap.            Bitmap bitmapWithReflection = Bitmap.createBitmap(                    reflectionWidth,                    srcHeight + reflectionHeight + REFLECTION_GAP,                     Config.ARGB_8888);                        if (null == bitmapWithReflection)            {                return null;            }                        // Prepare the canvas to draw stuff.            Canvas canvas = new Canvas(bitmapWithReflection);                        // Draw the original bitmap.            canvas.drawBitmap(srcBitmap, 0, 0, null);                        // Draw the reflection bitmap.            canvas.drawBitmap(reflectionBitmap, 0, srcHeight + REFLECTION_GAP, null);                        Paint paint = new Paint();            paint.setAntiAlias(true);            LinearGradient shader = new LinearGradient(                    0,                     srcHeight,                     0,                     bitmapWithReflection.getHeight() + REFLECTION_GAP,                     0x70FFFFFF,                     0x00FFFFFF,                    TileMode.MIRROR);            paint.setShader(shader);            paint.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.DST_IN));                        // Draw the linear shader.            canvas.drawRect(                    0,                     srcHeight,                     srcWidth,                     bitmapWithReflection.getHeight() + REFLECTION_GAP,                     paint);                        return bitmapWithReflection;        }        catch (Exception e)        {            e.printStackTrace();        }                return null;    }}