' 导入命名空间
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Math

public class PathGradientBrushesCenterColorSurroundColors
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class

public class Form1
  Inherits System.Windows.Forms.Form

  Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        Dim x As Integer = 10
        Dim y As Integer = 10
        Dim wid As Integer = 100
        Dim hgt As Integer = 50

        Dim rect_pts() As Point = { _
            New Point(x, y), _
            New Point(x + wid, y), _
            New Point(x + wid, y + hgt), _
            New Point(x, y + hgt) _
        }
        Dim path_brush As New PathGradientBrush(rect_pts)

        Dim ellipse_path As New GraphicsPath
        ellipse_path.AddEllipse(x, y, wid, hgt)
        path_brush = New PathGradientBrush(ellipse_path)
        path_brush.CenterColor = Color.White
        path_brush.SurroundColors = New Color() {Color.Black}
        e.Graphics.FillEllipse(path_brush, x, y, wid, hgt)

    End Sub


  Public Sub New()
   
    MyBase.New()
    Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
    Me.ClientSize = New System.Drawing.Size(292, 273)
    Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen

  End Sub

End Class