Problem with change form's pixel color in vb.net

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VB

Hi I'm trying to change the color of pixels for my form but nothing changed.

       private sub mybtn_click()  
       Dim MyPixel As System.Drawing.Bitmap
       Dim myColor As System.Drawing.Color
        myColor = System.Drawing.Color.FromArgb(0, 0, 0)
        MyPixel = New Bitmap(Me.Width, Me.Height)
        For i As Integer = 0 To 100
            For j As Integer = 0 To 100
                MyPixel.SetPixel(i, j, myColor)
                
            Next j
        Next 
end sub

after run when i click on my btn my pixels color changed but i can't see the new color. why?