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;
}

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;
}

android-ktx有Drawable。toBitmap方法:https://android.github.io/android-ktx/core-ktx/androidx.graphics.drawable/android.graphics.drawable.-drawable/to-bitmap.html

从芬兰湾的科特林

val bitmap = myDrawable.toBitmap()

 // get image path from gallery
protected void onActivityResult(int requestCode, int resultcode, Intent intent) {
    super.onActivityResult(requestCode, resultcode, intent);

    if (requestCode == 1) {
        if (intent != null && resultcode == RESULT_OK) {             
            Uri selectedImage = intent.getData();

            String[] filePathColumn = {MediaStore.Images.Media.DATA};
            Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            filePath = cursor.getString(columnIndex);

            //display image using BitmapFactory

            cursor.close(); bmp = BitmapFactory.decodeFile(filepath); 
            iv.setBackgroundResource(0);
            iv.setImageBitmap(bmp);
        }
    }
}

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

最新的androidx核心库(androidx.core:core-ktx:1.2.0)现在有一个扩展函数:Drawable. tobitmap(…)来将Drawable转换为Bitmap。