在C＃win中创建维恩图表格

Question

我需要以C＃格式创建维恩图表。我一直在尝试使用Graphics.DrawEllipse和FillElipse。但我不确定我如何填写常见部分。

我要做到这一点，

这里是我的这段代码，

private void panelControlVennDiagram_Paint(object sender, PaintEventArgs e) 
{ 
    Brush brushLeft = new SolidBrush(Color.Blue); 
    Brush brushRight = new SolidBrush(Color.LightPink); 
    Brush brushCommon = new SolidBrush(Color.Purple); 

    Pen pen = new Pen(brushLeft, 10); 

    Rectangle leftVenn = new Rectangle(20, 50,100,100); 
    Rectangle rightVenn = new Rectangle(90, 50, 100, 100); 
    Rectangle commonVenn = new Rectangle(100, 120, 100, 100); 

    Font stringFont = new Font("Times New Roman", 9); 

    e.Graphics.DrawString("Left:" + leftValue, stringFont, brushLeft, 10,70); 
    e.Graphics.DrawString("Right:" + rightValue, stringFont, brushRight, 90,70); 
    e.Graphics.DrawString("Common:" + commonValue,stringFont, brushCommon, 100,70); 

    // Fill ellipse on screen. 
    e.Graphics.FillEllipse(brushLeft, leftVenn); 
    e.Graphics.FillEllipse(brushRight, rightVenn); 

    e.Graphics.DrawEllipse(Pens.White, leftVenn); 
    e.Graphics.DrawEllipse(Pens.White, rightVenn); 

}

我绘制两个椭圆，需要有不同的颜色为通用部分。我无法使用任何图书馆。请帮忙。

Answer 1

您可以添加System.Drawing.Drawing2D;命名空间使用GraphicPath。创建一个图形路径并获取相交区域。

试试这个代码：（我曾评论DrawString用于测试目的）

private void panelControlVennDiagram_Paint(object sender, PaintEventArgs e) 
{ 
    Rectangle leftVenn = new Rectangle(20, 50, 100, 100); 
    Rectangle rightVenn = new Rectangle(90, 50, 100, 100);   
    Region region1 = new Region(); 

    //Font stringFont = new Font("Times New Roman", 9); 
    //e.Graphics.DrawString("Left:" , stringFont, brushLeft, 10, 70); 
    //e.Graphics.DrawString("Right:" , stringFont, brushRight, 90, 70); 
    //e.Graphics.DrawString("Common:", stringFont, brushCommon, 100, 70); 

    // Fill ellipse on screen. 
    using(Brush brushLeft = new SolidBrush(Color.Blue)) 
    {  
     e.Graphics.FillEllipse(brushLeft, leftVenn); 
     e.Graphics.DrawEllipse(Pens.White, leftVenn); 
    } 

    using(Brush brushRight = new SolidBrush(Color.LightPink)) 
    { 
     e.Graphics.FillEllipse(brushRight, rightVenn);   
     e.Graphics.DrawEllipse(Pens.White, rightVenn); 
    } 

    using (GraphicsPath circle_path = new GraphicsPath()) 
    { 
     circle_path.AddEllipse(leftVenn); 
     region1.Intersect(circle_path); 
    } 

    using (GraphicsPath circle_path = new GraphicsPath()) 
    { 
     circle_path.AddEllipse(rightVenn); 
     region1.Intersect(circle_path); 
    } 

    using(Brush brushCommon = new SolidBrush(Color.Purple)) 
    { 
     e.Graphics.FillRegion(brushCommon, region1); 
    } 

} 

输出：

Answer 2

你可以使用一个半透明的颜色，这样的颜色重叠部分是两个圆圈的实际复合颜色

Brush brushLeft = new SolidBrush(Color.FromArgb(50, Color.Blue)); 
Brush brushRight = new SolidBrush(Color.FromArgb(50, Color.Red));