Android 带有位图的画布中的默认黑色边框

Android 带有位图的画布中的默认黑色边框,android,android-canvas,android-bitmap,Android,Android Canvas,Android Bitmap,我想使用Bitmap,使用Canvas取整,但默认情况下使用黑色边框。 如何删除此边框 代码 public Bitmap transform(final Bitmap source) { Drawable drawable = context.getResources().getDrawable(R.drawable.dummy_image); float scale = Math.min(((float)drawable.getIntrinsicHeight() / so

我想使用
Bitmap
,使用
Canvas
取整,但默认情况下使用黑色边框。 如何删除此边框

代码

public Bitmap transform(final Bitmap source)
{
      Drawable drawable = context.getResources().getDrawable(R.drawable.dummy_image);

    float scale = Math.min(((float)drawable.getIntrinsicHeight() / source.getWidth()), ((float) drawable.getIntrinsicWidth() / source.getHeight()));

    Matrix matrix = new Matrix();
    matrix.postScale(scale, scale);

    Bitmap newBitmap = Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix, true);


    final Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(new BitmapShader(newBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));

    Bitmap output = Bitmap.createBitmap(drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(output);
    canvas.drawCircle((drawable.getIntrinsicWidth())/2,(drawable.getIntrinsicHeight())/2, getDrawableSize()-24, paint);

    if (source != output)
    {
        source.recycle();
    }
    return output;
}

这两行代码没有生成那个圆圈。@MikeM。请参见编辑的一行