VB.Net by API/System.Drawing.Drawing2D/CompositingMode

CompositingMode.SourceOver

  

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.rupositingMode = CompositingMode.SourceOver
        tempGraphics.rupositingQuality = CompositingQuality.GammaCorrected
        tempGraphics.FillRectangle(redBrush, rect1)
        rect1.X += 30
        rect1.Y += 30
        tempGraphics.FillEllipse(greenBrush, rect1)
        g.rupositingQuality = 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