带圆角的 UIView:如何正确剪辑子视图?

发布于 2024-12-13 19:45:15 字数 3105 浏览 0 评论 0原文

我创建了 UIView 的子类,它重写 drawRect: 并使用 AddArcToPoint() 绘制圆角。 (我不想使用图层的圆角半径属性,因为我需要定义哪些角必须是圆角的。) 然而我无法克服的问题是:如果我在 (0|0) 添加一个子视图,它会隐藏我的圆角。知道我该如何解决这个问题吗?我希望它剪辑得很好。

这是绘制圆角矩形的代码。它是 Monotouch,但任何开发人员都应该可读。

(您可以在这里找到完整的代码:https://github.com/Krumelur/RoundedRectView

public override void Draw (RectangleF rect)
        {
            using (var oContext = UIGraphics.GetCurrentContext())
            {
                oContext.SetLineWidth (this.StrokeWidth);
                oContext.SetStrokeColor (this.oStrokeColor.CGColor);
                oContext.SetFillColor (this.oRectColor.CGColor);

                RectangleF oRect = this.Bounds;

                float fRadius = this.CornerRadius;
                float fWidth = oRect.Width;
                float fHeight = oRect.Height;

                // Make sure corner radius isn't larger than half the shorter side.
                if (fRadius > fWidth / 2.0f)
                {
                    fRadius = fWidth / 2.0f;
                }
                if (fRadius > fHeight / 2.0f)
                {
                    fRadius = fHeight / 2.0f;    
                }

                float fMinX = oRect.GetMinX ();
                float fMidX = oRect.GetMidX ();
                float fMaxX = oRect.GetMaxX ();
                float fMinY = oRect.GetMinY ();
                float fMidY = oRect.GetMidY ();
                float fMaxY = oRect.GetMaxY ();

                // Move to left middle.
                oContext.MoveTo (fMinX, fMidY);

                // Arc to top middle.
                oContext.AddArcToPoint (fMinX, fMinY, fMidX, fMinY, (this.RoundCorners & ROUND_CORNERS.TopLeft) == ROUND_CORNERS.TopLeft ? fRadius : 0);
                // Arc to right middle.
                oContext.AddArcToPoint (fMaxX, fMinY, fMaxX, fMidY, (this.RoundCorners & ROUND_CORNERS.TopRight) == ROUND_CORNERS.TopRight ? fRadius : 0);
                // Arc to bottom middle.
                oContext.AddArcToPoint (fMaxX, fMaxY, fMidX, fMaxY, (this.RoundCorners & ROUND_CORNERS.BottomRight) == ROUND_CORNERS.BottomRight ? fRadius : 0);
                // Arc to left middle.
                oContext.AddArcToPoint (fMinX, fMaxY, fMinX, fMidY, (this.RoundCorners & ROUND_CORNERS.BottomLeft) == ROUND_CORNERS.BottomLeft ? fRadius : 0);

                // Draw the path.
                oContext.ClosePath ();
                oContext.DrawPath (CGPathDrawingMode.FillStroke);
            }
        }

编辑:

有一段代码演示了如何使用CALayer来解决它。

private void UpdateMask()
        {
            UIBezierPath oMaskPath = UIBezierPath.FromRoundedRect (this.Bounds, this.eRoundedCorners, new SizeF (this.fCornerRadius, this.fCornerRadius));

            CAShapeLayer oMaskLayer = new CAShapeLayer ();
            oMaskLayer.Frame = this.Bounds;
            oMaskLayer.Path = oMaskPath.CGPath;
            this.Layer.Mask = oMaskLayer;
        }

I created a subclass of UIView that overrides drawRect: and uses AddArcToPoint() to draw rounded corners. (I don't want to use the layer's corner radius property because I need to define which corners have to be rounded.)
The problem I cannot get over however: if I add a subview at (0|0), it hides my round corners. Any idea how I can fix this? I would like it to clip nicely.

Here's the code that draws the round cornered rectangle. It's Monotouch but should be readably by any developer.

(you can find the full code here: https://github.com/Krumelur/RoundedRectView)

public override void Draw (RectangleF rect)
        {
            using (var oContext = UIGraphics.GetCurrentContext())
            {
                oContext.SetLineWidth (this.StrokeWidth);
                oContext.SetStrokeColor (this.oStrokeColor.CGColor);
                oContext.SetFillColor (this.oRectColor.CGColor);

                RectangleF oRect = this.Bounds;

                float fRadius = this.CornerRadius;
                float fWidth = oRect.Width;
                float fHeight = oRect.Height;

                // Make sure corner radius isn't larger than half the shorter side.
                if (fRadius > fWidth / 2.0f)
                {
                    fRadius = fWidth / 2.0f;
                }
                if (fRadius > fHeight / 2.0f)
                {
                    fRadius = fHeight / 2.0f;    
                }

                float fMinX = oRect.GetMinX ();
                float fMidX = oRect.GetMidX ();
                float fMaxX = oRect.GetMaxX ();
                float fMinY = oRect.GetMinY ();
                float fMidY = oRect.GetMidY ();
                float fMaxY = oRect.GetMaxY ();

                // Move to left middle.
                oContext.MoveTo (fMinX, fMidY);

                // Arc to top middle.
                oContext.AddArcToPoint (fMinX, fMinY, fMidX, fMinY, (this.RoundCorners & ROUND_CORNERS.TopLeft) == ROUND_CORNERS.TopLeft ? fRadius : 0);
                // Arc to right middle.
                oContext.AddArcToPoint (fMaxX, fMinY, fMaxX, fMidY, (this.RoundCorners & ROUND_CORNERS.TopRight) == ROUND_CORNERS.TopRight ? fRadius : 0);
                // Arc to bottom middle.
                oContext.AddArcToPoint (fMaxX, fMaxY, fMidX, fMaxY, (this.RoundCorners & ROUND_CORNERS.BottomRight) == ROUND_CORNERS.BottomRight ? fRadius : 0);
                // Arc to left middle.
                oContext.AddArcToPoint (fMinX, fMaxY, fMinX, fMidY, (this.RoundCorners & ROUND_CORNERS.BottomLeft) == ROUND_CORNERS.BottomLeft ? fRadius : 0);

                // Draw the path.
                oContext.ClosePath ();
                oContext.DrawPath (CGPathDrawingMode.FillStroke);
            }
        }

EDIT:

Here's a piece of code that demonstrates how to solve it using CALayer.

private void UpdateMask()
        {
            UIBezierPath oMaskPath = UIBezierPath.FromRoundedRect (this.Bounds, this.eRoundedCorners, new SizeF (this.fCornerRadius, this.fCornerRadius));

            CAShapeLayer oMaskLayer = new CAShapeLayer ();
            oMaskLayer.Frame = this.Bounds;
            oMaskLayer.Path = oMaskPath.CGPath;
            this.Layer.Mask = oMaskLayer;
        }

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评论(2

感性不性感 2024-12-20 19:45:15

我还没有尝试过,但我认为你可以使用 CALayer 的 mask 属性来做到这一点。您必须将圆角矩形绘制到一个设置为视图图层蒙版的图层中。

I haven't tried it, but I think you could use CALayer's mask property to do this. You'd have to draw your rounded rectangle into a layer that was set as the mask to your view layer.

小兔几 2024-12-20 19:45:15

可以(事实上,非常容易)指定特定的圆角,而无需借助 drawRect: 或手动将部分圆角的矩形绘制到图层中。请参阅我对类似问题的回答

It is possible (and, in fact, very easy) to specify particular rounded corners without resorting to drawRect:, or manually drawing a partially rounded rect into a layer. See my answer on a similar question.

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