Drawable、Bitmap、byte[]之间的转换 (android转)

android在处理一写图片资源的时候，会进行一些类型的转换，现在有空整理一下：

1、Drawable → Bitmap 的简单方法
((BitmapDrawable)res.getDrawable(R.drawable.youricon)).getBitmap();

2、Drawable → Bitmap
Java代码
public static Bitmap drawableToBitmap(Drawable drawable) {

Bitmap bitmap = Bitmap
.createBitmap(
drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight(),
drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
//canvas.setBitmap(bitmap);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;
}

3.Bitmap→Drawable 的简单方法
BitmapDrawable bitmapDrawable = (BitmapDrawable)bitmap;
Drawable drawable = (Drawable)bitmapDrawable;

Bitmap bitmap = new Bitmap (...);
Drawable drawable = new BitmapDrawable(bitmap);

3、从资源中获取Bitmap
Java代码
Resources res=getResources();

Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.pic);

4、Bitmap → byte[]
Java代码
private byte[] Bitmap2Bytes(Bitmap bm){
ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
bm.compress(Bitmap.CompressFormat.PNG, 100, baos); 
return baos.toByteArray();
}

5、 byte[] → Bitmap
Java代码
private Bitmap Bytes2Bimap(byte[] b){
if(b.length!=0){
return BitmapFactory.decodeByteArray(b, 0, b.length);
}
else {
return null;
}
}