BitmapFactory.decodeResource()自动缩放位图，因此您的位图可能会变得模糊。为了防止结垢，请这样做:

BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false;
Bitmap source = BitmapFactory.decodeResource(context.getResources(),
                                             R.drawable.resource_name, options);

or

InputStream is = context.getResources().openRawResource(R.drawable.resource_name)
bitmap = BitmapFactory.decodeStream(is);

Android提供了一个非直接的解决方案:BitmapDrawable。为了获得位图，我们必须提供资源id R.drawable。flower_pic到BitmapDrawable，然后将其转换为Bitmap。

Bitmap bm = ((BitmapDrawable) getResources().getDrawable(R.drawable.flower_pic)).getBitmap();

一个可绘制对象可以被绘制到画布上，一个画布可以被位图支持:

(更新到处理BitmapDrawables的快速转换，并确保创建的位图具有有效的大小)

public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    int width = drawable.getIntrinsicWidth();
    width = width > 0 ? width : 1;
    int height = drawable.getIntrinsicHeight();
    height = height > 0 ? height : 1;

    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

我在这个帖子上使用了一些答案，但其中一些并没有像预期的那样工作(也许他们在旧版本中工作)，但我想在尝试了几次和错误后分享我的答案，使用扩展函数:

val markerOption = MarkerOptions().apply {
    position(LatLng(driver.lat, driver.lng))
    icon(R.drawabel.your_drawable.toBitmapDescriptor(context))
    snippet(driver.driverId.toString())
}
mMap.addMarker(markerOption)

这是扩展函数:

fun Int.toBitmapDescriptor(context: Context): BitmapDescriptor {
    val vectorDrawable = ResourcesCompat.getDrawable(context.resources, this, context.theme)
    val bitmap = vectorDrawable?.toBitmap(
        vectorDrawable.intrinsicWidth,
        vectorDrawable.intrinsicHeight,
        Bitmap.Config.ARGB_8888
    )
    return BitmapDescriptorFactory.fromBitmap(bitmap!!)
}

1)可绘制位图:

Bitmap mIcon = BitmapFactory.decodeResource(context.getResources(),R.drawable.icon);
// mImageView.setImageBitmap(mIcon);

2)位图到可绘制:

Drawable mDrawable = new BitmapDrawable(getResources(), bitmap);
// mImageView.setDrawable(mDrawable);

使用这段代码。它将帮助你实现你的目标。

 Bitmap bmp=BitmapFactory.decodeResource(getResources(), R.drawable.profileimage);
    if (bmp!=null) {
        Bitmap bitmap_round=getRoundedShape(bmp);
        if (bitmap_round!=null) {
            profileimage.setImageBitmap(bitmap_round);
        }
    }

  public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
    int targetWidth = 100;
    int targetHeight = 100;
    Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, 
            targetHeight,Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(targetBitmap);
    Path path = new Path();
    path.addCircle(((float) targetWidth - 1) / 2,
            ((float) targetHeight - 1) / 2,
            (Math.min(((float) targetWidth), 
                    ((float) targetHeight)) / 2),
                    Path.Direction.CCW);

    canvas.clipPath(path);
    Bitmap sourceBitmap = scaleBitmapImage;
    canvas.drawBitmap(sourceBitmap, 
            new Rect(0, 0, sourceBitmap.getWidth(),
                    sourceBitmap.getHeight()), 
                    new Rect(0, 0, targetWidth, targetHeight), new Paint(Paint.FILTER_BITMAP_FLAG));
    return targetBitmap;
}