Drawable和Bitmap转换

一、Bitmap转Drawable
Bitmap bm=xxx; //xxx依据你的情况获取
BitmapDrawable bd=new BitmapDrawable(bm);
由于BtimapDrawable是Drawable的子类，终于直接使用bd对象就可以。

二、 Drawable转Bitmap
转成Bitmap对象后，能够将Drawable对象通过Android的SK库存成一个字节输出流，终于还能够保存成为jpg和png的文件。
Drawable d=xxx; //xxx依据自己的情况获取drawable

BitmapDrawable bd = (BitmapDrawable) d;

Bitmap bm = bd.getBitmap();
终于bm就是我们须要的Bitmap对象了。

// 从资源中获取Bitmap
public static Bitmap getBitmapFromResources(Activity act, int resId) {
Resources res = act.getResources();
return BitmapFactory.decodeResource(res, resId);
}
// byte[] → Bitmap
public static Bitmap convertBytes2Bimap(byte[] b) {
if (b.length == 0) {
return null;
}
return BitmapFactory.decodeByteArray(b, 0, b.length);
}

// Bitmap → byte[]
public static byte[] convertBitmap2Bytes(Bitmap bm) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
return baos.toByteArray();
}
// 1)Drawable → Bitmap
public static Bitmap convertDrawable2BitmapByCanvas(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;
}
// 2)Drawable → Bitmap
public static Bitmap convertDrawable2BitmapSimple(Drawable drawable){
BitmapDrawable bd = (BitmapDrawable) drawable;
return bd.getBitmap();
}
// Bitmap → Drawable
public static Drawable convertBitmap2Drawable(Bitmap bitmap) {
BitmapDrawable bd = new BitmapDrawable(bitmap);
// 由于BtimapDrawable是Drawable的子类，终于直接使用bd对象就可以。
return bd;
}