This code shows how to set a MDI child forma as classical form
And vice-versa
Sample project attached
And vice-versa
Code:
' #VBIDEUtils#************************************************************
' * Author :
' * Web Site :
' * E-Mail :
' * Date : 11/01/2021
' * Time : 12:45
' * Module Name : Module1
' * Module Filename : Module1.bas
' * Purpose :
' * Purpose :
' **********************************************************************
' * Comments :
' *
' *
' * Example :
' *
' * See Also :
' *
' * History :
' *
' *
' **********************************************************************
Option Explicit
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWndParent&, ByVal hWndChildAfter&, ByVal lpClassName$, ByVal lpWindowName$) As Long
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long
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 IsWindow Lib "user32.dll" (ByVal hWnd As Long) As Long
Public Declare Function SetParent Lib "user32" (ByVal hWndChild As Long, ByVal hWndNewParent As Long) As Long
Private Const GWL_STYLE = (-16)
Private Const WS_MAXIMIZEBOX = &H10000
Private Const WS_MINIMIZEBOX = &H20000
Private Sub DisableEnableMinMax(oForm As Form, bDisable As Boolean)
' #VBIDEUtils#***********************************************************
' * Author :
' * Web Site : http://www.syndicassist.com
' * E-Mail : info@syndicassist.com
' * Date : 06/26/2008
' * Time : 18:05
' * Module Name : Module1
' * Module Filename : Module1.bas
' * Procedure Name : DisableEnableMinMax
' * Purpose :
' * Parameters :
' * oForm As Form
' * bDisable As Boolean
' * Purpose :
' **********************************************************************
' * Comments :
' *
' *
' * Example :
' *
' * See Also :
' *
' * History :
' *
' *
' **********************************************************************
' #VBIDEUtilsERROR#
On Error GoTo ERROR_DisableEnableMinMax
Dim nRet As Long
' *** The following code strips out the minimize and maximize buttons from the main MDI Frame.
' *** There is no other way to do this that I can find. Note that if you want to set the form caption dynamically, you must do this first, because
' *** the caption sets the window style when set dynamically, and undoes all the work.
' *** Get current window style value
nRet = GetWindowLong(oForm.hWnd, GWL_STYLE)
If bDisable Then
' *** Remove style settings for the buttons
nRet = nRet Xor WS_MINIMIZEBOX
nRet = nRet Xor WS_MAXIMIZEBOX
Else
nRet = nRet Or WS_MINIMIZEBOX
nRet = nRet Or WS_MAXIMIZEBOX
End If
' *** Put the style back
nRet = SetWindowLong(oForm.hWnd, GWL_STYLE, nRet)
EXIT_DisableEnableMinMax:
On Error Resume Next
Exit Sub
' #VBIDEUtilsERROR#
ERROR_DisableEnableMinMax:
Resume EXIT_DisableEnableMinMax
End Sub
Private Function LoadChildForm(frmChild As VB.Form, hWndParent As Long, Optional bDesktop As Boolean = False) As Long
' #VBIDEUtils#************************************************************
' * Author :
' * Web Site :
' * E-Mail :
' * Date : 11/01/2021
' * Time : 12:45
' * Module Name : Module1
' * Module Filename : Module1.bas
' * Procedure Name : LoadChildForm
' * Purpose :
' * Parameters :
' * frmChild As VB.Form
' * hWndParent As Long
' * Optional bDesktop As Boolean = False
' * Purpose :
' **********************************************************************
' * Comments :
' *
' *
' * Example :
' *
' * See Also :
' *
' * History :
' *
' *
' **********************************************************************
' #VBIDEUtilsERROR#
On Error GoTo ERROR_LoadChildForm
If Not bDesktop And (hWndParent = 0) Then
Err.Raise vbObjectError + 1, "LoadChildForm", "bDesktop flag must be True if you wish to set " & "this form to be a child of desktop."
Exit Function
End If
If (Not CBool(IsWindow(hWndParent))) And (hWndParent <> 0) Then
Err.Raise vbObjectError + 1, "LoadChildForm", "Invalid parent window handle."
Exit Function
End If
Load frmChild
LoadChildForm = SetParent(frmChild.hWnd, hWndParent)
EXIT_LoadChildForm:
On Error Resume Next
Exit Function
' #VBIDEUtilsERROR#
ERROR_LoadChildForm:
Resume EXIT_LoadChildForm
End Function
Public Sub MDI_Not_Child(frmChild As Form)
' #VBIDEUtils#************************************************************
' * Author :
' * Web Site :
' * E-Mail :
' * Date : 10/26/2019
' * Time : 11:06
' * Module Name : Module1
' * Module Filename : Module1.bas
' * Procedure Name : MDI_Not_Child
' * Purpose :
' * Parameters :
' * frmChild As Form
' * Purpose :
' **********************************************************************
' * Comments :
' *
' *
' * Example :
' *
' * See Also :
' *
' * History :
' *
' *
' **********************************************************************
' #VBIDEUtilsERROR#
On Error GoTo ERROR_MDI_Not_Child
Call DisableEnableMinMax(frmChild, False)
Call LoadChildForm(frmChild, 0, True)
EXIT_MDI_Not_Child:
On Error Resume Next
Exit Sub
' #VBIDEUtilsERROR#
ERROR_MDI_Not_Child:
Resume EXIT_MDI_Not_Child
End Sub
Public Sub MDI_To_Child(frmParent As Form, frmChild As Form)
' #VBIDEUtils#************************************************************
' * Author :
' * Web Site :
' * E-Mail :
' * Date : 10/06/2019
' * Time : 08:49
' * Module Name : Module1
' * Module Filename : Module1.bas
' * Procedure Name : MDI_To_Child
' * Purpose :
' * Parameters :
' * frmParent As Form
' * frmChild As Form
' * Purpose :
' **********************************************************************
' * Comments :
' *
' *
' * Example :
' *
' * See Also :
' *
' * History :
' *
' *
' **********************************************************************
' #VBIDEUtilsERROR#
On Error GoTo ERROR_MDI_To_Child
Dim hClientArea As Long
hClientArea = FindWindowEx(frmParent.hWnd, 0&, "MDIClient", vbNullChar)
Call DisableEnableMinMax(frmChild, True)
Call LoadChildForm(frmChild, hClientArea)
frmChild.Move 0, 0
EXIT_MDI_To_Child:
On Error Resume Next
Exit Sub
' #VBIDEUtilsERROR#
ERROR_MDI_To_Child:
Resume EXIT_MDI_To_Child
End SubCode:
Private Sub Command1_Click()
If Command1.Tag = vbNullString Then
Call MDI_Not_Child(Me)
Command1.Tag = "MDI"
Else
Call MDI_To_Child(frmMain, Me)
Command1.Tag = vbNullString
End If
End Sub