Private Sub SetAndFillClip(ByVal e As PaintEventArgs)

    ' Set the Clip property to a new region.
    e.Graphics.Clip = New Region(New Rectangle(10, 10, 100, 200))

    ' Fill the region.
    e.Graphics.FillRegion(Brushes.LightSalmon, e.Graphics.Clip)

    ' Demonstrate the clip region by drawing a string
    ' at the outer edge of the region.
    e.Graphics.DrawString("Outside of Clip", _
        New Font("Arial", 12.0F, FontStyle.Regular), _
        Brushes.Black, 0.0F, 0.0F)

End Sub

' 导入命名空间
Imports System
Imports System.ComponentModel
Imports System.Windows.Forms
Imports System.Data
Imports System.Configuration
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Text
Imports System.Globalization
Imports System.Text
Imports System.Collections

Public Class MainClass
    
    Shared Sub Main()
        
        Dim myform As Form = New ClippingRegionForm()
        Application.Run(myform)
    End Sub
End Class



Public Class ClippingRegionForm
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        components = New System.ComponentModel.Container()
        Me.Text = "ClippingRegionForm"
    End Sub

#End Region

    Private Sub ClippingRegionForm_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Dim g As Graphics = e.Graphics

        Dim path As GraphicsPath = New GraphicsPath()
        path.AddEllipse(Me.ClientRectangle)
        Dim region As Region = New Region(path)
        g.DrawPath(Pens.Red, path)
        g.Clip = region

        Dim rect As Rectangle = Me.ClientRectangle
        rect.Offset(20, 20)
        rect.Width = rect.Width - 40
        rect.Height = rect.Height - 40
        g.FillRectangle(Brushes.Black, rect)

    End Sub
End Class