您需要返回一个有效的位图.对于VectorDrawable,有必要做更多的事情.您可以使用以下方法：
private static Bitmap bitmapFromDrawable(Context context, int drawableId) {
Drawable drawable = ContextCompat.getDrawable(context, drawableId);
if (drawable instanceof VectorDrawable) {
return bitmapFromVectorDrawable((VectorDrawable) drawable);
}
return ((BitmapDrawable) drawable).getBitmap();
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static Bitmap bitmapFromVectorDrawable(VectorDrawable vectorDrawable) {
Bitmap bitmap = Bitmap.createBitmap(vectorDrawable.getIntrinsicWidth(), vectorDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
vectorDrawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
vectorDrawable.draw(canvas);
return bitmap;
}
然后您可以像这样使用它：
builder.setCloseButtonIcon(bitmapFromDrawable(this, R.drawable. ic_arrow_back_white_24dp));
