Changing the "Working Area" of a screen.

I am trying to develop an application that will act a bit like a second taskbar, in that it will resize the working area of a screen so that maximised applications do not cover over it, or simply get hidden behind it. Examples of applications that use this would be things such as Desktop Sidebar or JetToolbar. I am trying to develop the application in Visual Basic 2005 Express Edition (using the .NET Framework 2.0). I have found how to get the current working area, but despite extensive searching I have not found a way to change it. Is this possible in Visual Basic

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Changing the "Working Area" of a screen.

Paul Raj
Oi, my brain just isn't with me today... VB.NET code you say... try the code midway down this page.
Rania
Thank you very much for your tip, but I was referring to the working area of the screen, not my form. The working area of the screen is the are not taken up by the taskbar etc., and seems to dictate the size of maximised programs. Some applications seem able to change it though, so that windows does not try and use the parts of the screen that they display in when a program is maximised. Also, allow me to clarify: when I said "or simply get hidden behind it" in my original question, I was stating that I did not want this to happen, on reading it again it seems ambiguos to me.
Darren Tao
Well done, Brendan. I haven't tested it yet, but It seems to match all the C# etc. code I've seen, well done, and thanks.
ChupaChupa
I'll guess that that has the right code, although I can't say that I can see it, on account of not having either A: an account there or B: a credit card to buy an account with
keithster

Let me paste the post in question:

Imports System
Imports System.Drawing
Imports System.Collections
Imports System.ComponentModel
Imports System.Windows.Forms
Imports System.Data
Imports System.Runtime.InteropServices

Public Class Form1
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.
Friend WithEvents Button1 As System.Windows.Forms.Button
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.Button1 = New System.Windows.Forms.Button()
Me.SuspendLayout()
'
'Button1
'
Me.Button1.Location = New System.Drawing.Point(72, 80)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(80, 40)
Me.Button1.TabIndex = 0
Me.Button1.Text = "Close"
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(292, 266)
Me.Controls.Add(Me.Button1)
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)

End Sub

#End Region

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
RegisterBar()
End Sub

Structure RECT
Public left As Integer
Public top As Integer
Public right As Integer
Public bottom As Integer
End Structure 'RECT

Structure APPBARDATA
Public cbSize As Integer
Public hWnd As IntPtr
Public uCallbackMessage As Integer
Public uEdge As Integer
Public rc As RECT
Public lParam As IntPtr
End Structure 'APPBARDATA
Enum ABMsg

ABM_NEW = 0
ABM_REMOVE = 1
ABM_QUERYPOS = 2
ABM_SETPOS = 3
ABM_GETSTATE = 4
ABM_GETTASKBARPOS = 5
ABM_ACTIVATE = 6
ABM_GETAUTOHIDEBAR = 7
ABM_SETAUTOHIDEBAR = 8
ABM_WINDOWPOSCHANGED = 9
ABM_SETSTATE=10

End Enum
Enum ABNotify

ABN_STATECHANGE = 0
ABN_POSCHANGED
ABN_FULLSCREENAPP
ABN_WINDOWARRANGE

End Enum
Enum ABEdge

ABE_LEFT = 0
ABE_TOP
ABE_RIGHT
ABE_BOTTOM
End Enum

Private fBarRegistered As Boolean = False

Public Declare Function SHAppBarMessage Lib "shell32.dll" Alias "SHAppBarMessage" (ByVal dwMessage As Integer, ByRef pData As APPBARDATA) As System.UInt32
Public Declare Function GetSystemMetrics Lib "User32.dll" Alias "GetSystemMetrics" (ByVal index As Integer) As Integer
Public Declare Function MoveWindow Lib "User32.dll" Alias "MoveWindow" (ByVal hWnd As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal cx As Integer, ByVal cy As Integer, ByVal repaint As Boolean) As Boolean
Private Declare Auto Function RegisterWindowMessage Lib "User32.dll" (ByVal msg As String) As Integer
Private uCallBack As Integer

Private Sub RegisterBar()
Dim abd As New APPBARDATA()
abd.cbSize = Marshal.SizeOf(abd)
abd.hWnd = Me.Handle
If Not fBarRegistered Then
uCallBack = RegisterWindowMessage("AppBarMessage")
abd.uCallbackMessage = uCallBack

Dim ret As System.UInt32 = SHAppBarMessage(CInt(ABMsg.ABM_NEW), abd) 'ToDo: Unsigned Integers not supported
fBarRegistered = True

ABSetPos()

Else
SHAppBarMessage(CInt(ABMsg.ABM_REMOVE), abd)
fBarRegistered = False
End If
End Sub 'RegisterBar

Private Sub ABSetPos()
Dim abd As New APPBARDATA()
abd.cbSize = Marshal.SizeOf(abd)
abd.hWnd = Me.Handle
abd.uEdge = CInt(ABEdge.ABE_TOP)

If abd.uEdge = CInt(ABEdge.ABE_LEFT) Or abd.uEdge = CInt(ABEdge.ABE_RIGHT) Then
abd.rc.top = 0
abd.rc.bottom = SystemInformation.PrimaryMonitorSize.Height
If abd.uEdge = CInt(ABEdge.ABE_LEFT) Then
abd.rc.left = 0
abd.rc.right = Size.Width
Else
abd.rc.right = SystemInformation.PrimaryMonitorSize.Width
abd.rc.left = abd.rc.right - Size.Width
End If

Else
abd.rc.left = 0
abd.rc.right = SystemInformation.PrimaryMonitorSize.Width
If abd.uEdge = CInt(ABEdge.ABE_TOP) Then
abd.rc.top = 0
abd.rc.bottom = Size.Height
Else
abd.rc.bottom = SystemInformation.PrimaryMonitorSize.Height
abd.rc.top = abd.rc.bottom - Size.Height
End If
End If

' Query the system for an approved size and position.
SHAppBarMessage(CInt(ABMsg.ABM_QUERYPOS), abd)

' Adjust the rectangle, depending on the edge to which the
' appbar is anchored.
Select Case abd.uEdge
Case CInt(ABEdge.ABE_LEFT)
abd.rc.right = abd.rc.left + Size.Width
Case CInt(ABEdge.ABE_RIGHT)
abd.rc.left = abd.rc.right - Size.Width
Case CInt(ABEdge.ABE_TOP)
abd.rc.bottom = abd.rc.top + Size.Height
Case CInt(ABEdge.ABE_BOTTOM)
abd.rc.top = abd.rc.bottom - Size.Height
End Select

' Pass the final bounding rectangle to the system.
SHAppBarMessage(CInt(ABMsg.ABM_SETPOS), abd)

' Move and size the appbar so that it conforms to the
' bounding rectangle passed to the system.
MoveWindow(abd.hWnd, abd.rc.left, abd.rc.top, abd.rc.right - abd.rc.left, abd.rc.bottom - abd.rc.top, True)
End Sub 'ABSetPos

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
If m.Msg = uCallBack Then
Select Case m.WParam.ToInt32()
Case CInt(ABNotify.ABN_POSCHANGED)
ABSetPos()
End Select
End If

MyBase.WndProc(m)
End Sub 'WndProc

Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
Get
Dim cp As CreateParams = MyBase.CreateParams
cp.Style = cp.Style And Not &HC00000 ' WS_CAPTION
cp.Style = cp.Style And Not &H800000 ' WS_BORDER
cp.ExStyle = &H80 Or &H8 ' WS_EX_TOOLWINDOW | WS_EX_TOPMOST
Return cp
End Get
End Property

Private Sub End_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
RegisterBar()
End
End Sub
End Class
ashish1482

Your form’s WorkingArea property is directly related to the form’s Size property, the primary difference being the Working area is the Size minus the form borders, title bars and what not.

If you increase your form’s Size (or just it’s Length or Width), the WorkingArea will increase as well.
landre3567
Thanks again for the help, and this looks to hit the nail on the head, although it is only in C++ and C# which I have never tried using before, and so I am now looking again for help, but am probably nearer as I now know I should be registering as an appbar instead of tring to resize the workingarea.
dwebb

Oopsie. I had suspected that... but didn’t persue it...

When it comes to doing this sort of thing for the entire screen... instead of changing the working area directly, I believe that you would register your window/app as an appbar. Try this tutorial for information on that.
Changing the "Working Area" of a screen.

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