Windows窗体删除绘制椭圆

Question

我已经创造了一些椭圆Windows窗体上

我想要的选择，而鼠标，如果我选择任何椭圆它将从窗口

这里删除了一些代码，在创建椭圆C＃

public void DrawCircle_Paint(object sender, PaintEventArgs e) 
{ 
    Pen pen = new Pen(Color.Black, 3); Graphics gr = this.CreateGraphics(); gr.DrawEllipse(pen, 40, 45, 20, 20); 
    Pen pen2 = new Pen(Color.Black, 3); Graphics gr1 = this.CreateGraphics(); gr.DrawEllipse(pen2, 30, 25, 38, 20); 
    Pen pen3 = new Pen(Color.Black, 3); Graphics gr2 = this.CreateGraphics(); gr.DrawEllipse(pen3, 35, 36, 68, 15); 
    Pen pen4 = new Pen(Color.Black, 3); Graphics gr3 = this.CreateGraphics(); gr.DrawEllipse(pen4, 50, 60, 67, 35); 
} 

Answer 1

你可以使用

this.Invalidate(); 

应该CLEA [R他们....

要么，

Graphics.Clear(); 

编辑：

其实，另一种方法是让你的鼠标悬停内一个布尔值，并用它来决定何时绘制椭圆/不是。作为一般说明，您应该将椭圆图绘制为onpaint的重写。目前，如果您要使屏幕失效（无论是由您还是由Windows），您的形状将会消失。一个使用油漆的例子。

bool paint = false; 
protected override void OnPaint(object sender, PaintEventArgs e) 
{ 
    if (paint) 
    { 
      Pen pen = new Pen(Color.Black, 3); Graphics gr = this.CreateGraphics(); gr.DrawEllipse(pen, 40, 45, 20, 20); 
      Pen pen2 = new Pen(Color.Black, 3); Graphics gr1 = this.CreateGraphics(); gr.DrawEllipse(pen2, 30, 25, 38, 20); 
      Pen pen3 = new Pen(Color.Black, 3); Graphics gr2 = this.CreateGraphics(); gr.DrawEllipse(pen3, 35, 36, 68, 15); 
      Pen pen4 = new Pen(Color.Black, 3); Graphics gr3 = this.CreateGraphics(); gr.DrawEllipse(pen4, 50, 60, 67, 35); 
    } 
} 

我不记得具体paramters它，但在你的OnMouseHover（要关闭elipse）

OnMouseHover(){ 
    ... 
    paint = false; 
    this.Invalidate(); 
}