Android中Bitmap和Drawable相互转换

1.Drawable转换成Bitmap

Resources res=getResources();
Bitmap bmp =BitmapFactory.decodeResource(res, R.drawable.simple);

2.Bitmap转换成Drawable

Drawable drawable =new BitmapDrawable(bmp);

3、Drawable转换成固定大小的Bitmap

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;