Bitmap Bitmap = BitmapFactory.decodeResource(context.getResources()， R.drawable.icon);

这将不会每次工作，例如，如果你的可绘制层列表可绘制，然后它给出一个空响应，所以作为一个替代方案，你需要绘制你的可绘制到画布，然后保存为位图，请参考下面的一杯代码。

public void drawableToBitMap(Context context, int drawable, int widthPixels, int heightPixels) {
    try {
        File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/", "drawable.png");
        FileOutputStream fOut = new FileOutputStream(file);
        Drawable drw = ResourcesCompat.getDrawable(context.getResources(), drawable, null);
        if (drw != null) {
            convertToBitmap(drw, widthPixels, heightPixels).compress(Bitmap.CompressFormat.PNG, 100, fOut);
        }
        fOut.flush();
        fOut.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private Bitmap convertToBitmap(Drawable drawable, int widthPixels, int heightPixels) {
    Bitmap bitmap = Bitmap.createBitmap(widthPixels, heightPixels, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, widthPixels, heightPixels);
    drawable.draw(canvas);
    return bitmap;
}

以上代码保存为drawable.png在下载目录

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;
}

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);

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!!)
}

public static Bitmap drawableToBitmap (Drawable drawable) {
    Bitmap bitmap = null;

    if (drawable instanceof BitmapDrawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        if(bitmapDrawable.getBitmap() != null) {
            return bitmapDrawable.getBitmap();
        }
    }

    if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
        bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
    } else {
        bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
    }

    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);
    return bitmap;
}

这是更好的分辨率

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

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

    return bitmap;
}

public static InputStream bitmapToInputStream(Bitmap bitmap) {
    int size = bitmap.getHeight() * bitmap.getRowBytes();
    ByteBuffer buffer = ByteBuffer.allocate(size);
    bitmap.copyPixelsToBuffer(buffer);
    return new ByteArrayInputStream(buffer.array());
}

如何将可绘制的位读取为输入流的代码