Android中几种图像特效处理

大家好,这一节给大家分享的是Android中几种图像特效处理的小技巧,比如圆角,倒影,还有就是图片缩放,Drawable转化为Bitmap,Bitmap转化为Drawable等等.

废话少说了,直接讲解今天的实例,本例主要是先获取壁纸(getWallpaper()),然后对当前壁纸的一些特效处理.大家按步骤一步一步来:

第一步:新建一个Android工程命名为ImageDemo,工程结构如下:

第二步:新建一个.java文件,命名为ImageUtil.java,在里面定义一些图片处理方法,代码如下:

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1. package com.android.tutor; 
2. import android.graphics.Bitmap; 
3. import android.graphics.Canvas; 
4. import android.graphics.LinearGradient; 
5. import android.graphics.Matrix; 
6. import android.graphics.Paint; 
7. import android.graphics.PixelFormat; 
8. import android.graphics.PorterDuffXfermode; 
9. import android.graphics.Rect; 
10. import android.graphics.RectF; 
11. import android.graphics.Bitmap.Config; 
12. import android.graphics.PorterDuff.Mode; 
13. import android.graphics.Shader.TileMode; 
14. import android.graphics.drawable.Drawable; 
15. public class ImageUtil { 
17. //放大缩小图片
18. public static Bitmap zoomBitmap(Bitmap bitmap,int w,int h){ 
19. int width = bitmap.getWidth(); 
20. int height = bitmap.getHeight(); 
21.         Matrix matrix = new Matrix(); 
22. float scaleWidht = ((float)w / width); 
23. float scaleHeight = ((float)h / height); 
24.         matrix.postScale(scaleWidht, scaleHeight); 
25.         Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); 
26. return newbmp; 
27.     } 
28. //将Drawable转化为Bitmap
29. public static Bitmap drawableToBitmap(Drawable drawable){ 
30. int width = drawable.getIntrinsicWidth(); 
31. int height = drawable.getIntrinsicHeight(); 
32.             Bitmap bitmap = Bitmap.createBitmap(width, height, 
33.                     drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 
34.                             : Bitmap.Config.RGB_565); 
35.             Canvas canvas = new Canvas(bitmap); 
36.             drawable.setBounds(0,0,width,height); 
37.             drawable.draw(canvas); 
38. return bitmap; 
40.         } 
42. //获得圆角图片的方法
43. public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx){ 
45.         Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap 
46.                 .getHeight(), Config.ARGB_8888); 
47.         Canvas canvas = new Canvas(output); 
49. final int color = 0xff424242; 
50. final Paint paint = new Paint(); 
51. final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
52. final RectF rectF = new RectF(rect); 
54.         paint.setAntiAlias(true); 
55.         canvas.drawARGB(0, 0, 0, 0); 
56.         paint.setColor(color); 
57.         canvas.drawRoundRect(rectF, roundPx, roundPx, paint); 
59.         paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 
60.         canvas.drawBitmap(bitmap, rect, rect, paint); 
62. return output; 
63.     } 
64. //获得带倒影的图片方法
65. public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){ 
66. final int reflectionGap = 4; 
67. int width = bitmap.getWidth(); 
68. int height = bitmap.getHeight(); 
70.         Matrix matrix = new Matrix(); 
71.         matrix.preScale(1, -1); 
73.         Bitmap reflectionImage = Bitmap.createBitmap(bitmap,  
74. 0, height/2, width, height/2, matrix, false); 
76.         Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888); 
78.         Canvas canvas = new Canvas(bitmapWithReflection); 
79.         canvas.drawBitmap(bitmap, 0, 0, null); 
80.         Paint deafalutPaint = new Paint(); 
81.         canvas.drawRect(0, height,width,height + reflectionGap, 
82.                 deafalutPaint); 
84.         canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null); 
86.         Paint paint = new Paint(); 
87.         LinearGradient shader = new LinearGradient(0, 
88.                 bitmap.getHeight(), 0, bitmapWithReflection.getHeight() 
89.                 + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP); 
90.         paint.setShader(shader); 
91. // Set the Transfer mode to be porter duff and destination in
92.         paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); 
93. // Draw a rectangle using the paint with our linear gradient
94.         canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() 
95.                 + reflectionGap, paint); 
97. return bitmapWithReflection; 
98.     } 
100. } 

第三步:修改main.xml布局文件,主要放了两个ImageView控件,代码如下:

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1. <?xml version="1.0" encoding="utf-8"?> 
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3.     android:orientation="vertical"
4.     android:layout_width="fill_parent"
5.     android:layout_height="fill_parent"
6.     > 
7.     <ImageView  
8.         android:id="@+id/image01"
9.         android:layout_width="wrap_content"
10.         android:layout_height="wrap_content"
11.         android:padding="10px"
12.         /> 
13.     <ImageView 
14.         android:id="@+id/image02"
15.         android:layout_width="wrap_content"
16.         android:layout_height="wrap_content"
17.         android:padding="10px"
18.     /> 
19. </LinearLayout> 

第四步:修改主核心程序,ImageDemo.java,代码如下:

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1. package com.android.tutor; 
2. import android.app.Activity; 
3. import android.graphics.Bitmap; 
4. import android.graphics.drawable.Drawable; 
5. import android.os.Bundle; 
6. import android.widget.ImageView; 
7. public class Imagedemo extends Activity { 
8. private ImageView mImageView01,mImageView02; 
10. public void onCreate(Bundle savedInstanceState) { 
11. super.onCreate(savedInstanceState); 
12.         setContentView(R.layout.main); 
13.         setupViews(); 
14.     } 
16. private void setupViews(){ 
17.         mImageView01 = (ImageView)findViewById(R.id.image01); 
18.         mImageView02 = (ImageView)findViewById(R.id.image02); 
20. //获取壁纸返回值是Drawable
21.         Drawable drawable = getWallpaper(); 
22. //将Drawable转化为Bitmap
23.         Bitmap bitmap = ImageUtil.drawableToBitmap(drawable); 
24. //缩放图片
25.         Bitmap zoomBitmap = ImageUtil.zoomBitmap(bitmap, 100, 100); 
26. //获取圆角图片
27.         Bitmap roundBitmap = ImageUtil.getRoundedCornerBitmap(zoomBitmap, 10.0f); 
28. //获取倒影图片
29.         Bitmap reflectBitmap = ImageUtil.createReflectionImageWithOrigin(zoomBitmap); 
30. //这里可以让Bitmap再转化为Drawable
31. //      Drawable roundDrawable = new BitmapDrawable(roundBitmap);      
32. //      Drawable reflectDrawable = new BitmapDrawable(reflectBitmap);      
33. //      mImageView01.setBackgroundDrawable(roundDrawable);
34. //      mImageView02.setBackgroundDrawable(reflectDrawable);
36.         mImageView01.setImageBitmap(roundBitmap); 
37.         mImageView02.setImageBitmap(reflectBitmap); 
38.     } 
41. } 

第五步:运行上述工程,查看效果如下:

OK大功告成了!!

作者：Android_Tutor

出处：http://blog.csdn.net/Android_Tutor/archive/2010/11/02/5981753.aspx