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

public class AlphaBCompGammaCorr
   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 g As Graphics = Me.CreateGraphics()
        g.Clear(Me.BackColor)
        Dim rect1 As New Rectangle(20, 20, 100, 100)
        Dim rect2 As New Rectangle(200, 20, 100, 100)
        Dim redBrush As New SolidBrush(Color.FromArgb(150, 255, 0, 0))
        Dim greenBrush As New SolidBrush(Color.FromArgb(180, 0, 255, 0))

        Dim tempBmp As New Bitmap(200, 150)
        Dim tempGraphics As Graphics = Graphics.FromImage(tempBmp)
        tempGraphics.CompositingMode = CompositingMode.SourceOver
        tempGraphics.CompositingQuality = CompositingQuality.GammaCorrected
        tempGraphics.FillRectangle(redBrush, rect1)
        rect1.X += 30
        rect1.Y += 30
        tempGraphics.FillEllipse(greenBrush, rect1)
        g.CompositingQuality = CompositingQuality.GammaCorrected
        g.DrawImage(tempBmp, 0, 0)

        g.FillRectangle(Brushes.Red, rect2)
        rect2.X += 30
        rect2.Y += 30
        g.FillEllipse(Brushes.Green, rect2)

        tempBmp.Dispose()
        g.Dispose()
  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