Android Drawable、Bitmap、byte[]之间的转换

1、Drawable --> Bitmap

[java]

1.     Bitmap drawable2Bitmap(Drawable drawable) {  
2.         if (drawable instanceof BitmapDrawable) {  
3.             return ((BitmapDrawable) drawable).getBitmap();  
4.         } else if (drawable instanceof NinePatchDrawable) {  
5.             Bitmap bitmap = Bitmap  
6.                     .createBitmap(  
7.                             drawable.getIntrinsicWidth(),  
8.                             drawable.getIntrinsicHeight(),  
9.                             drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888  
10.                                     : Bitmap.Config.RGB_565);  
11.             Canvas canvas = new Canvas(bitmap);  
12.             drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),  
13.                     drawable.getIntrinsicHeight());  
14.             drawable.draw(canvas);  
15.             return bitmap;  
16.         } else {  
17.             return null;  
18.         }  
19.     }  

2、从资源中获取的Drawable --> Bitmap

[java]

1.     Resources res = getResources();  
2.     Bitmap bmp = BitmapFactory.decodeResource(res, R.drawable.pic);  

3、Bitmap --> Drawable

[java]

1.     Drawable bitmap2Drawable(Bitmap bitmap) {  
2.         return new BitmapDrawable(bitmap);  
3.     }  

4、Bitmap --> byte[]

[java]

1.     byte[] Bitmap2Bytes(Bitmap bm) {  
2.         ByteArrayOutputStream baos = new ByteArrayOutputStream();  
3.         bm.compress(Bitmap.CompressFormat.PNG, 100, baos);  
4.         return baos.toByteArray();  
5.     }  

5、 byte[] --> Bitmap

[java]

1.     Bitmap Bytes2Bimap(byte[] b) {  
2.         if (b.length != 0) {  
3.             return BitmapFactory.decodeByteArray(b, 0, b.length);  
4.         } else {  
5.             return null;  
6.         }  
7.     }