' Quote from
'Windows Forms Programming in VB
'by Chris Sells (Author), Justin Gehtland (Author)
'Publisher: Addison-Wesley Professional; 1st edition (October 24, 2003)
'Language: English
'ISBN-10: 0321125193
'ISBN-13: 978-0321125194
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
public class TransparentFormDemo
public Shared Sub Main
Application.Run(New TransparentForm)
End Sub
End class
Public Class TransparentForm
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
Me.SetStyle(ControlStyles.ResizeRedraw, True)
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()
'
'TransparentForm
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(208, 68)
Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
Me.Name = "TransparentForm"
Me.Text = "Transparency Test"
End Sub
#End Region
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
MyBase.WndProc(m)
Dim WM_NCHITTEST As Integer = &H84
If m.Msg <> WM_NCHITTEST Then Exit Sub
Dim HTCLIENT As Integer = 1
Dim HTCAPTION As Integer = 2
If m.Result.ToInt32() = HTCLIENT Then m.Result = New IntPtr(HTCAPTION)
Dim HTLEFT As Integer = 10
Dim HTRIGHT As Integer = 11
Dim HTTOP As Integer = 12
Dim HTTOPLEFT As Integer = 13
Dim HTTOPRIGHT As Integer = 14
Dim HTBOTTOM As Integer = 15
Dim HTBOTTOMLEFT As Integer = 16
Dim HTBOTTOMRIGHT As Integer = 17
Dim clientLocation As Point = Me.PointToClient(New Point(m.LParam.ToInt32))
Dim x As Integer = clientLocation.X
Dim y As Integer = clientLocation.Y
If x = 0 And y = 0 Then
m.Result = New IntPtr(HTCAPTION)
Exit Sub
ElseIf x = 0 And y >= 0 Then
m.Result = New IntPtr(HTRIGHT)
Exit Sub
ElseIf x = 0 Then
m.Result = New IntPtr(HTLEFT)
Exit Sub
ElseIf y = 0 And x >= 0 Then
m.Result = New IntPtr(HTTOP)
Exit Sub
ElseIf y = 0 Then
m.Result = New IntPtr(HTBOTTOM)
Exit Sub
End If
Dim slopeAbs As Double = Math.Abs(CDbl(y) / CDbl(x))
If x > 0 And y > 0 Then
' Q1
If slopeAbs > 2 Then
m.Result = New IntPtr(HTTOP)
ElseIf slopeAbs < 0.5 Then
m.Result = New IntPtr(HTRIGHT)
Else
m.Result = New IntPtr(HTTOPRIGHT)
End If
ElseIf x > 0 And y < 0 Then
' Q2
If slopeAbs > 2 Then
m.Result = New IntPtr(HTBOTTOM)
ElseIf slopeAbs < 0.5 Then
m.Result = New IntPtr(HTRIGHT)
Else
m.Result = New IntPtr(HTBOTTOMRIGHT)
End If
ElseIf x < 0 And y < 0 Then
' Q3
If slopeAbs > 2 Then
m.Result = New IntPtr(HTBOTTOM)
ElseIf slopeAbs < 0.5 Then
m.Result = New IntPtr(HTLEFT)
Else
m.Result = New IntPtr(HTBOTTOMLEFT)
End If
Else
' Q4
If slopeAbs > 2 Then
m.Result = New IntPtr(HTTOP)
ElseIf slopeAbs < 0.5 Then
m.Result = New IntPtr(HTLEFT)
Else
m.Result = New IntPtr(HTTOPLEFT)
End If
End If
End Sub
End Class