vbAccelerator - Show and Hide a Form's Titlebar at run-time:

This tip shows you how to show and hide the title bar of a window at run-time. To make a window's title bar disappear, you have to remove the control box, the maximise box and the minimise box as well as set the caption of the form to blank. Unfortunately, VB's ControlBox, MinButton and MaxButton properties of a form are read-only so you can normally only do this at design time. However, by manipulating the style of the window using API calls, you can get the same thing to happen at run-time.

Start a new project in VB. Add the following code to the project's form:

Private Declare Function SetWindowLong Lib "user32" _
Alias "SetWindowLongA" _
(ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function GetWindowLong Lib "user32" _
Alias "GetWindowLongA" _
(ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Const GWL_STYLE = (-16)
Private Const WS_CAPTION = &HC00000 ' WS_BORDER Or WS_DLGFRAME
Private Const WS_MAXIMIZEBOX = &H10000
Private Const WS_MINIMIZEBOX = &H20000
Private Const WS_SYSMENU = &H80000

Private Declare Function SetWindowPos Lib "user32" _
(ByVal hwnd As Long, ByVal hWndInsertAfter As Long, _
ByVal x As Long, ByVal y As Long, _
ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long
Private Enum ESetWindowPosStyles
SWP_SHOWWINDOW = &H40
SWP_HIDEWINDOW = &H80
SWP_FRAMECHANGED = &H20 ' The frame changed: send WM_NCCALCSIZE
SWP_NOACTIVATE = &H10
SWP_NOCOPYBITS = &H100
SWP_NOMOVE = &H2
SWP_NOOWNERZORDER = &H200 ' Don't do owner Z ordering
SWP_NOREDRAW = &H8
SWP_NOREPOSITION = SWP_NOOWNERZORDER
SWP_NOSIZE = &H1
SWP_NOZORDER = &H4
SWP_DRAWFRAME = SWP_FRAMECHANGED
HWND_NOTOPMOST = -2
End Enum

Private Declare Function GetWindowRect Lib "user32" ( _
ByVal hwnd As Long, lpRect As RECT) As Long
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type

Private Function ShowTitleBar(ByVal bState As Boolean)
Dim lStyle As Long
Dim tR As RECT

' Get the window's position:
GetWindowRect Me.hwnd, tR

' Modify whether title bar will be visible:
lStyle = GetWindowLong(Me.hwnd, GWL_STYLE)
If (not bState) Then
Me.Caption = Me.Tag
If Me.ControlBox Then
lStyle = lStyle Or WS_SYSMENU
End If
If Me.MaxButton Then
lStyle = lStyle Or WS_MAXIMIZEBOX
End If
If Me.MinButton Then
lStyle = lStyle Or WS_MINIMIZEBOX
End If
If Me.Caption <> "" Then
lStyle = lStyle Or WS_CAPTION
End If
Else
Me.Tag = Me.Caption
Me.Caption = ""
lStyle = lStyle And Not WS_SYSMENU
lStyle = lStyle And Not WS_MAXIMIZEBOX
lStyle = lStyle And Not WS_MINIMIZEBOX
lStyle = lStyle And Not WS_CAPTION
End If
SetWindowLong Me.hwnd, GWL_STYLE, lStyle

' Ensure the style takes and make the window the
' same size, regardless that the title bar etc
' is now a different size:
SetWindowPos Me.hwnd, _
0, tR.Left, tR.Top, _
tR.Right - tR.Left, tR.Bottom - tR.Top, _
SWP_NOREPOSITION Or SWP_NOZORDER Or SWP_FRAMECHANGED

Me.Refresh

' Ensure that your resize code is fired, as the client area
' has changed:
Form_Resize

End Function

To try out the hiding and showing the title bar, add a CheckBox to the project's form. Set the check box's Value property to 1 (Checked). Then put the following code under the Check box's click event:

Private Sub Check1_Click()
If (Check1.Value = Checked) Then
ShowTitleBar True
Else
ShowTitleBar False
End If
End Sub

When you click on the check box, the form's titlebar will be alternately hidden and shown.