使用Region属性。
先创建GraphicsPath对像,在其中实现一个圆,然后应用于控件的region属性.下面是MSDN中关于创建圆形按钮的示例:
private void roundButton_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
System.Drawing.Drawing2D.GraphicsPath buttonPath =
new System.Drawing.Drawing2D.GraphicsPath();
System.Drawing.Rectangle newRectangle = roundButton.ClientRectangle;
newRectangle.Inflate(-10, -10);
e.Graphics.DrawEllipse(System.Drawing.Pens.Black, newRectangle);
newRectangle.Inflate( 1,
1);
buttonPath.AddEllipse(newRectangle);.
roundButton.Region = new System.Drawing.Region(buttonPath);
}