Access Cookbook - Ken Getz [165]
Set the form's AutoCenter property to Yes.
Add the following code to the declarations section at the top of the form's module (replacing the values with the actual names for your table and splash form, if you've used different names):
Private Const acbPreloadTable = "zstblPreloadForms"
Private Const acbSplashForm = "frmSplash"
Create a new event procedure for the form's Open event. (If you're unsure of how to do this, see How Do I Create an Event Procedure? in the Preface of this book.)
Add the following code to the event procedure:
Private Sub Form_Open(Cancel As Integer)
' Preload forms.
Dim db As DAO.Database
Dim rst As DAO.Recordset
Dim varFormName As Variant
On Error GoTo HandleErr
DoCmd.OpenForm acbSplashForm
Set db = CurrentDb( )
' Preload the forms listed in zstblPreloadForms.
Set rst = db.OpenRecordset(acbPreloadTable, dbOpenSnapshot)
Do While Not rst.EOF
varFormName = rst("FormName")
If Not IsNull(varFormName) Then
DoCmd.OpenForm FormName:=varFormName, _
WindowMode:=acHidden, OpenArgs:="StayLoaded"
End If
rst.MoveNext
Loop
ExitHere:
DoCmd.Close acForm, acbSplashForm
If Not rst Is Nothing Then
rst.Close
End If
Set rst = Nothing
Exit Sub
HandleErr:
MsgBox "Error " & Err.Number & ": " & Err.Description, , "Form Open"
Resume ExitHere
End Sub
You can also copy this code from the frmSwitchboard1 form (not the frmSwitchboard form) in 08-01.MDB. (The frmSwitchboard1 version of the form always preloads forms, thus eliminating all the code associated with the "Preload and keep loaded forms" checkbox.)
Create an event procedure for the switchboard form's Close event. Add this code to the event procedure:
Private Sub Form_Close( )
' Unload preloaded forms
Dim db As DAO.Database
Dim rst As DAO.Recordset
Dim varFormName As Variant
On Error GoTo HandleErr
Set db = CurrentDb( )
' Unload the forms listed in zstblPreloadForms
Set rst = db.OpenRecordset(acbPreloadTable, dbOpenSnapshot)
Do Until rst.EOF
varFormName = rst("FormName")
If Not IsNull(varFormName) Then
DoCmd.Close acForm, varFormName
End If
rst.MoveNext
Loop
ExitHere:
If Not rst Is Nothing Then
rst.Close
End If
Set rst = Nothing
Exit Sub
HandleErr:
MsgBox "Error " & Err.Number & ": " & Err.Description, , "Form Open"
Resume ExitHere
End Sub
Create the following functions in a global module (or import the basStayLoaded module from 08-01.MDB):
Public Function acbOpenForm(strFormName As String, _
fStayLoaded As Boolean) As Boolean
' Open specified form and pass it the
' StayLoaded argument.
On Error GoTo acbOpenFormErr
If fStayLoaded Then
DoCmd.OpenForm strFormName, OpenArgs:="StayLoaded"
Else
DoCmd.OpenForm strFormName
End If
acbOpenFormExit:
Exit Function
acbOpenFormErr:
MsgBox "Error " & Err.Number & ": " & Err.Description, _
vbOKOnly + vbCritical, "acbOpenForm"
Resume acbOpenFormExit
End Function
Public Function acbCloseForm(frmToClose As Form)
' If StayLoaded is True, hide the form instead of closing it.
On Error GoTo acbCloseFormErr
If InStr(frmToClose.OpenArgs, "StayLoaded") > 0 Then
frmToClose.Visible = False
Else
DoCmd.Close acForm, frmToClose.Name
End If
acbCloseFormExit:
Exit Function
acbCloseFormErr:
MsgBox "Error " & Err.Number & ": " & Err.Description, _
vbOKOnly + vbCritical, "acbCloseForm"
Resume acbCloseFormExit
End Function
Throughout your application, when you create code that opens a form and you wish to load that form only once, call the acbOpenForm function from Step 8. If you wish to open a form from code, you can use this syntax:
Call acbOpenForm("formname", True)
You can also call the function directly from an event property. In this case, enter the following in the event property:
=acbOpenForm("formname", True)
For those forms that you don't wish to keep loaded, change the second parameter of acbOpenForm to False.
For each form you are preloading or loading with the acbOpenForm function, add a command button with the caption "Close". Enter the following