Android 设置图片倒影效果

首先，贴出效果图：

1.布局文件main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

    <ImageView
        android:id="@+id/picture_qian"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:src="@drawable/horse" />

</LinearLayout>

2.MainActivity界面java代码：

 1 package com.easymorse.picture;
 2 
 3 import android.app.Activity;
 4 import android.graphics.Bitmap;
 5 import android.graphics.Bitmap.Config;
 6 import android.graphics.Canvas;
 7 import android.graphics.LinearGradient;
 8 import android.graphics.Matrix;
 9 import android.graphics.Paint;
10 import android.graphics.PorterDuff.Mode;
11 import android.graphics.PorterDuffXfermode;
12 import android.graphics.Shader.TileMode;
13 import android.graphics.drawable.BitmapDrawable;
14 import android.os.Bundle;
15 import android.widget.ImageView;
16 
17 public class MainActivity extends Activity {
18     /** Called when the activity is first created. */
19     @Override
20     public void onCreate(Bundle savedInstanceState) {
21         super.onCreate(savedInstanceState);
22         setContentView(R.layout.main);
23         ImageView imageView2 = (ImageView) findViewById(R.id.picture_qian);
24 
25         Bitmap bmp = ((BitmapDrawable) getResources().getDrawable(
26                 R.drawable.horse)).getBitmap();
27 
28         imageView2.setImageBitmap(createReflectedImage(bmp));
29     }
30 
31     public static Bitmap createReflectedImage(Bitmap originalImage) {
32 
33         final int reflectionGap = 4;
34 
35         int width = originalImage.getWidth();
36         int height = originalImage.getHeight();
37 
38         Matrix matrix = new Matrix();
39         matrix.preScale(1, -1);
40 
41         Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
42                 height / 2, width, height / 2, matrix, false);
43 
44         Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
45                 (height + height / 2), Config.ARGB_8888);
46 
47         Canvas canvas = new Canvas(bitmapWithReflection);
48 
49         canvas.drawBitmap(originalImage, 0, 0, null);
50 
51         Paint defaultPaint = new Paint();
52         canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);
53 
54         canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
55 
56         Paint paint = new Paint();
57         LinearGradient shader = new LinearGradient(0,
58                 originalImage.getHeight(), 0, bitmapWithReflection.getHeight()
59                         + reflectionGap, 0x70ffffff, 0x00ffffff,
60                 TileMode.MIRROR);
61 
62         paint.setShader(shader);
63 
64         paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
65 
66         canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
67                 + reflectionGap, paint);
68 
69         return bitmapWithReflection;
70     }
71 }