无法从Android中的ImageView将图像保存到图库

Drawable drawable = imageView.getDrawable();

Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();

String displayName = "image_" + System.currentTimeMillis() + ".jpg";
String mimeType = "image/jpeg";

ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.DISPLAY_NAME, displayName);
values.put(MediaStore.Images.Media.MIME_TYPE, mimeType);

ContentResolver resolver = getContentResolver();
Uri imageUri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

OutputStream outputStream;
try {
    outputStream = resolver.openOutputStream(imageUri);
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
    outputStream.close();
} catch (IOException e) {
    e.printStackTrace();
}

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />