仅显示bezierpath

Question

我想绘制消息单元格（见附图）。它应该有颜色填充和外部边界概述。问题在于它显示了我不需要的内部边界。 代码：

    public static UIBezierPath CreateMessageBubble (CGRect frame, float cornerRaduis, float quoteBubbleLength, bool leftSide)
            {   
                //var shape = CreateMessageBubbleWithQuote (frame, cornerRaduis, quoteBubbleLength, leftSide);
                //return shape;
                bool left = leftSide;

                UIBezierPath roundedPath = UIBezierPath.FromRoundedRect (
                    new CGRect (frame.X + (left ? quoteBubbleLength : 0), frame.Y, frame.Width - quoteBubbleLength, frame.Height), 
                    UIRectCorner.AllCorners, 
                    new CGSize (cornerRaduis, cornerRaduis)
                );

                roundedPath.UsesEvenOddFillRule = false;

                if (left) {
                    roundedPath.MoveTo (new CGPoint (quoteBubbleLength + cornerRaduis, frame.Height - cornerRaduis));
                    roundedPath.AddCurveToPoint (
                        new CGPoint (0, frame.Height), 
                        new CGPoint (quoteBubbleLength + cornerRaduis * 0.25f, frame.Height),
                        new CGPoint (0, frame.Height)
                    );
                    roundedPath.AddCurveToPoint (
                        new CGPoint (quoteBubbleLength, frame.Height - cornerRaduis), 
                        new CGPoint (0, frame.Height),
                        new CGPoint (quoteBubbleLength, frame.Height - cornerRaduis * 0.5f)
                    );
                } else {
                    roundedPath.MoveTo (new CGPoint (frame.Width - quoteBubbleLength, frame.Height - cornerRaduis));
                    roundedPath.AddCurveToPoint (
                        new CGPoint (frame.Width, frame.Height), 
                        new CGPoint (frame.Width - quoteBubbleLength, frame.Height - cornerRaduis * 0.5f),
                        new CGPoint (frame.Width, frame.Height)
                    );
                    roundedPath.AddCurveToPoint (
                        new CGPoint (frame.Width - (quoteBubbleLength + cornerRaduis), frame.Height - cornerRaduis), 
                        new CGPoint (frame.Width, frame.Height),
                        new CGPoint (frame.Width - (quoteBubbleLength + cornerRaduis * 0.25f), frame.Height)
                    );
                }

                roundedPath.ClosePath ();
                roundedPath.AddClip ();

                return roundedPath;
}

填写和设置笔划的代码：

using (CGContext gctx = UIGraphics.GetCurrentContext ()) {
                var shape =  BlrtiOS.Util.BlrtUtilities.CreateMessageBubble (Bounds, CornerRadius, AligmentPadding, _alignmentLeft);
                gctx.SetFillColor (_bubbleColor.CGColor);
                gctx.SetStrokeColor (BlrtStyles.iOS.Green.CGColor);
                gctx.SetLineWidth (1);

                gctx.AddPath (shape.CGPath);
                gctx.DrawPath (CGPathDrawingMode.FillStroke);   
            }

所需：

当前：