WPF矩形-圆角

Question

如何才能让WPF矩形的顶角变圆？

我创建了一个边框并设置了CornerRadius属性，并且在边框中添加了我的矩形，但它不起作用，矩形不是圆角的。

<Border BorderThickness="1" CornerRadius="50,50,0,0" BorderBrush="Black">
    <Rectangle Fill="#FF5A9AE0" Stretch="UniformToFill" ClipToBounds="True"/>
</Border>

Answer 1

你得到的问题是矩形“溢出”了你边框的圆角。

矩形不能有单独的圆角，所以如果您只是将背景颜色放在边框上并删除矩形：

<Border BorderThickness="1" Grid.Row="0" Grid.ColumnSpan="2"
        CornerRadius="50,50,0,0" BorderBrush="Black" Background="#FF5A9AE0">
</Border>

你会得到你想要的效果。

Answer 2

在矩形上设置RadiusX和RadiusY属性，这将为其提供圆角

Answer 3

一个很好的例子是如何用DrawingContext来做OnRender：

​

​

   /// <summary>
    /// Draws a rounded rectangle with four individual corner radius
    /// </summary>
    public static void DrawRoundedRectangle(this DrawingContext dc, Brush brush,
        Pen pen, Rect rect, CornerRadius cornerRadius)
    {
        var geometry = new StreamGeometry();
        using (var context = geometry.Open())
        {
            bool isStroked = pen != null;
            const bool isSmoothJoin = true;

            context.BeginFigure(rect.TopLeft + new Vector(0, cornerRadius.TopLeft), brush != null, true);
            context.ArcTo(new Point(rect.TopLeft.X + cornerRadius.TopLeft, rect.TopLeft.Y), 
                new Size(cornerRadius.TopLeft, cornerRadius.TopLeft),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);
            context.LineTo(rect.TopRight - new Vector(cornerRadius.TopRight, 0), isStroked, isSmoothJoin);
            context.ArcTo(new Point(rect.TopRight.X, rect.TopRight.Y + cornerRadius.TopRight), 
                new Size(cornerRadius.TopRight, cornerRadius.TopRight),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);
            context.LineTo(rect.BottomRight - new Vector(0, cornerRadius.BottomRight), isStroked, isSmoothJoin);
            context.ArcTo(new Point(rect.BottomRight.X - cornerRadius.BottomRight, rect.BottomRight.Y), 
                new Size(cornerRadius.BottomRight, cornerRadius.BottomRight),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);
            context.LineTo(rect.BottomLeft + new Vector(cornerRadius.BottomLeft, 0), isStroked, isSmoothJoin);
            context.ArcTo(new Point(rect.BottomLeft.X, rect.BottomLeft.Y - cornerRadius.BottomLeft), 
                new Size(cornerRadius.BottomLeft, cornerRadius.BottomLeft),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);

            context.Close();
        }
        dc.DrawGeometry(brush, pen, geometry);
    }

信息来源：http://wpftutorial.net/DrawRoundedRectangle.html