Paint the form. 

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)

    {

      if(OuterPath==null)

        return;

      Pen p=new Pen(Color.DarkGray,4);

      p.Alignment=PenAlignment.Inset;

      e.Graphics.DrawPath(p,OuterPath);

 

      p.Color=Color.LightGray;

      p.Width=2;

 

      e.Graphics.SmoothingMode=SmoothingMode.AntiAlias;

      e.Graphics.DrawPath(p,OuterPath);

 

      if(closerPos!=0)

      {

        GraphicsPath gp=new GraphicsPath();

        gp.AddArc(this.Size.Width-90,0,90,90,270,90);

        gp.AddLine(this.Size.Width,45,this.Size.Width,0);

        gp.CloseFigure();

 

        e.Graphics.Clip=new Region(gp);

 

        e.Graphics.DrawImage(closeBitmap,new Rectangle(this.Size.Width-45,45-closerPos,closerPos,closerPos),0,0,closeBitmap.Width,closeBitmap.Height,GraphicsUnit.Pixel);

      }

 

      p.Dispose();

    }

    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint

      If OuterPath Is Nothing Then

        Return

      End If

      Dim p As New Pen(Color.DarkGray, 4)

      p.Alignment = PenAlignment.Inset

      e.Graphics.DrawPath(p, OuterPath)

 

      p.Color = Color.LightGray

      p.Width = 2

 

      e.Graphics.SmoothingMode = SmoothingMode.AntiAlias

      e.Graphics.DrawPath(p, OuterPath)

 

      If closerPos <> 0 Then

        Dim gp As New GraphicsPath

        gp.AddArc(Me.Size.Width - 90, 0, 90, 90, 270, 90)

        gp.AddLine(Me.Size.Width, 45, Me.Size.Width, 0)

        gp.CloseFigure()

 

        e.Graphics.Clip = New [Region](gp)

 

        e.Graphics.DrawImage(closeBitmap, New Rectangle(Me.Size.Width - 45, 45 - closerPos, closerPos, closerPos), 0, 0, closeBitmap.Width, closeBitmap.Height, GraphicsUnit.Pixel)

      End If

 

      p.Dispose()

    End Sub 'Form1_Paint