Private Sub ShowRectangleUnion(ByVal e As PaintEventArgs)

    ' Declare two rectangles and draw them.
    Dim rectangle1 As New Rectangle(30, 40, 50, 100)
    Dim rectangle2 As New Rectangle(50, 60, 100, 60)
    e.Graphics.DrawRectangle(Pens.Sienna, rectangle1)
    e.Graphics.DrawRectangle(Pens.BlueViolet, rectangle2)

    ' Declare a third rectangle as a union of the first two.
    Dim rectangle3 As Rectangle = Rectangle.Union(rectangle1, _
        rectangle2)

    ' Fill in the third rectangle in a semi-transparent color.
    Dim transparentColor As Color = Color.FromArgb(40, 135, 135, 255)
    e.Graphics.FillRectangle(New SolidBrush(transparentColor), _
        rectangle3)
End Sub

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

public class RectangleUnion
   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)
        ' Create a Graphics object
        Dim g As Graphics = Me.CreateGraphics()
        ' Create PointF, SizeF and RectangleF
        Dim pt As New PointF(30.8F, 20.7F)
        Dim sz As New SizeF(60.0F, 40.0F)
        Dim rect2 As New RectangleF(40.2F, 40.6F, 100.5F, 100.0F)
        Dim rect1 As New RectangleF(pt, sz)
        Dim rect3 As Rectangle = Rectangle.Ceiling(rect1)
        Dim rect4 As Rectangle = Rectangle.Truncate(rect1)
        Dim rect5 As Rectangle = Rectangle.Round(rect2)
        ' Draw rectangles
        g.DrawRectangle(Pens.Black, rect3)
        g.DrawRectangle(Pens.Red, rect5)

        Dim unionRect As Rectangle = Rectangle.Union(rect4, rect5)
        ' Draw new rectangle
        g.DrawRectangle(Pens.Green, unionRect)


  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