Public Declare Function GetDesktopWindow Lib "user32" Alias "GetDesktopWindow" () As IntPtr

Public Declare Function GetDCEx Lib "user32" Alias "GetDCEx" (ByVal hwnd As IntPtr, ByVal hrgnclip As IntPtr, ByVal fdwOptions As Integer) As IntPtr

'下面是画模块

Dim WithEvents TestGroupBox As New GroupBox

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

e.Graphics.Clear(TestGroupBox.BackColor)

e.Graphics.DrawString(TestGroupBox.Text, TestGroupBox.Font, Brushes.Red, 10, 1)

Dim a, b, c, d As Integer

a = TextBox2.Left

b = TextBox2.Top

c = TextBox2.Width

d = TextBox2.Height

TextBox2.Text = a & "-" & b & "-" & c & "-" & d

e.Graphics.DrawLine(Pens.Blue, a, b, a + c, b)

e.Graphics.DrawLine(Pens.Blue, a, b, a, b + d)

e.Graphics.DrawLine(Pens.Blue, a + c, b, a + c, b + d)

e.Graphics.DrawLine(Pens.Blue, a, b + d, a + c, b + d)

End Sub

'画图代码

Dim desk As Integer = GetDesktopWindow()

Dim deskDC As Integer = GetDCEx(desk, IntPtr.Zero, &H403)

Dim g As Graphics = Graphics.FromHdc(deskDC)

g.FillEllipse(SystemBrushes.ControlText, 0, 0, 100, 100)

g.Dispose()