How to validate several userform textboxes? - excel

Question

I have a workbook with userforms to write to several numeric and date fields. I need to validate the textbox control for proper numbers and dates.
Rather than replicate the validation for each textbox, I thought I would call a common subprocedure within the BeforeUpdae event of each textbox.
I have two problems.
If I execute the form and test using text in tbAmount box, it seems the ContolValidate procedure is not called.
If I run it in break mode with a breakpoint on Call ContolValidate(What, CurrentControl), it will step through that procedure.
Even though it steps through the procedure, the Cancel = True does not seem to work.
If I paste the ContolValidate code directly in the BeforeUpdate, the Cancel = True does work.
This code is all on the userform.
Private Sub tbAmount1_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)
Dim What As String
Dim CurrentControl As Control
What = "NumericField"
Set CurrentControl = Me.ActiveControl
Call ContolValidate(What, CurrentControl)
End Sub
Private Sub ContolValidate(What, CurrentControl)
If Not IsNumeric(CurrentControl.Value) Then
ErrorLabel.Caption = "Please correct this entry to be numeric."
Cancel = True
CurrentControl.BackColor = rgbPink
CurrentControl.SelStart = 0
CurrentControl.SelLength = Len(CurrentControl.Value)
Else
If CurrentControl.Value < 0 Then
ErrorLabel.Caption = "This number cannot be negative."
Cancel = True
CurrentControl.BackColor = rgbPink
CurrentControl.SelStart = 0
CurrentControl.SelLength = Len(CurrentControl.Value)
End If
End If
End Sub
Private Sub tbAmount1_AfterUpdate()
ErrorLabel.Visible = False
tbAmount1.BackColor = Me.BackColor
End Sub

Answer 1

(1) When your control is named tbAmount1 and the code is in the code-behind module of the form, the trigger should fire.
(2) As #shahkalpesh mentioned in his comment, Cancel is not known in your validate-routine. Putting Option Explicit at the top of you code would show you that.
I would suggest to convert the routine to a function. In the code below, I return True if the content is okay and False if not (so you need to put a Not to the result to set the Cancel-parameter)
Private Sub tbAmount1_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)
Cancel = Not ControlValidate("NumericField", Me.ActiveControl)
End Sub
Private Function ControlValidate(What, CurrentControl) As Boolean
ControlValidate = False
If Not IsNumeric(CurrentControl.Value) Then
errorlabel.Caption = "Please correct this entry to be numeric."
ElseIf CurrentControl.Value < 0 Then
errorlabel.Caption = "This number cannot be negative."
Else
ControlValidate = True ' Input is okay.
End If
If ControlValidate Then
CurrentControl.BackColor = vbWhite
Else
CurrentControl.BackColor = rgbPink
CurrentControl.SelStart = 0
CurrentControl.SelLength = Len(CurrentControl.Value)
End If
End Function
P.S.: I changed the name to ControlValidate - "contol" seems wrong to me...