Proper Validation of xtpControlEdit (VB6) : Excellent post - thanks Milkman,...

Sun, 07 May 2006 10:52:57 +0000

Author: apuhjee
Subject: 2909
Posted: 07 May 2006 at 10:52am

Excellent post - thanks Milkman, you saved a few hairs on my head!

Cheers ~ jp

Proper Validation of xtpControlEdit (VB6) : Most of my applications...

Fri, 16 Sep 2005 23:06:14 +0000

Author: Milkman
Subject: 2909
Posted: 16 September 2005 at 11:06pm

Most of my applications require that any text entered into an edit boxbe checked for consistency. For instance, if the user enters xyzin an ID# edit box, you wouldn't want your program to use a lettervalue when it should use a number value. The typical desiredresult would be to discard the incorrectly entered value and restorethe previous contents of the edit box.

Unfortunately, the method in which to do this isn't exactly spelled outin the substandard documentation. Adding insult to injury, thereisn't even an editbox worked into ANY of the command bar samples. Below is the required code to implement proper validation of anxtpControlEdit within a command bar. It uses the Tag (they callit the "Paramater") property of the edit control to store the previouscontents of the edit box.

You'll first need to create an ID number for the editbox. Createthis global value in a seperate module where you store your constants.

Public Const ID_EDIT = 205

You then need to construct your command bar.

Private Sub cbToolbar()

'Declare Temporary Variables
Dim Control As CommandBarControl
Dim Toolbar As CommandBar
Dim EditControl As CommandBarEdit

'Set Toolbar properties
Set Toolbar = CommandBars.Add("Test Command Bar", xtpBarBottom)

'Create Toolbar
With Toolbar.Controls
     Set EditControl = .Add(xtpControlEdit, ID_EDIT, "")
            EditControl.Text = "Test"
            EditControl.Parameter = EditControl.Text
End With

End Sub

After the control exists you'll needto put some additional code in the "ControlSelected" (catchs when youpress the Enter key) and "Update" (catch the case where you change thetext and then just leave the text box without pressing the enter key)Events.

Private Sub CommandBars_ControlSelected(ByVal Control As XtremeCommandBars.ICommandBarControl)

'Process Selected Events
If Control Is Nothing Then Exit Sub
Select Case Control.Id
    Case ID_EDIT:
        If Control.Parameter <> Control.Text Then EditBox_Validate Control
End Select

End Sub

Private Sub CommandBars_Update(ByVal Control As XtremeCommandBars.ICommandBarControl)

'Process Update Requests
If Control Is Nothing Then Exit Sub
Select Case Control.Id
    Case ID_EDIT:
       If (Control.HasFocus = False) And (Control.Text <>Control.Parameter) Then EditBox_Validate Control
End Select

End Sub

You're probably wondering why the "If Control Is Nothing Then Exit Sub"line at the beginning of each event handler. Well it would appearthat these event handlers are sometimes called without a controlvariable passed to it. Very strange. The example programschoose to use the "On Error Resume Next" command to juse ignore anyerrors. I don't like this approach because it turns off errorchecking for the rest of the code in the event handler. A badthing when you're trying to debug your program.

Finally you'll need to add the validation routine. Use something like this.

Private Sub EditBox_Validate(ByRef EditBox As CommandBarEdit)
'This sub will validate the edit box text

'Check the text in the EditBox.Text property

'If bad then replace replace .Text with .Parameter
'Maybe you want to raise an error

'If text is good then let it be and update the .Parameter for the next time the 
'validate routine is called

'Validation Successful
EditBox.Parameter = EditBox.Text
End Sub

If you want your program to programmatically update the text in theeditbox; make sure to change BOTH the .Text and the .Parameterproperties to avoid having the validate routine execute needlessly.

Now if I can only figure out how to centre text in the thing, I'll be set.

Edited by Milkman

Codejock Developer Community : Proper Validation of xtpControlEdit (VB6)

Proper Validation of xtpControlEdit (VB6) : Excellent post - thanks Milkman,...

Proper Validation of xtpControlEdit (VB6) : Most of my applications...