Android Drawable、Bitmap、byte[]之间的转换

1、Drawable --> Bitmap

Bitmap drawable2Bitmap(Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
return ((BitmapDrawable) drawable).getBitmap();
} else if (drawable instanceof NinePatchDrawable) {
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);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;
} else {
return null;
}
}

2、从资源中获取的Drawable --> Bitmap

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

3、Bitmap --> Drawable

Drawable bitmap2Drawable(Bitmap bitmap) {
return new BitmapDrawable(bitmap);
}

4、Bitmap --> byte[]

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

5、 byte[] --> Bitmap

Bitmap Bytes2Bimap(byte[] b) {
if (b.length != 0) {
return BitmapFactory.decodeByteArray(b, 0, b.length);
} else {
return null;
}
}