Page 314 - Excel Progamming Weekend Crash Course

r540629 ch22.qxd 9/2/03 9:35 AM Page 289

Session 22 — A User Form Example 289

ValidateData = False
Exit Function
End If
If txtAddress.Value = “” Then
MsgBox “You must enter an address.”
ValidateData = False
Exit Function
End If
If txtCity.Value = “” Then
MsgBox “You must enter a city.”
ValidateData = False
Exit Function
End If
If cmbStates.Value = “” Then
MsgBox “You must select a state.”
ValidateData = False
Exit Function
End If
If txtZip.TextLength <> 5 Then
MsgBox “You must enter a 5 digit zip code.”
ValidateData = False
Exit Function
End If

ValidateData = True

End Function

Part 6: Completing the Project
To be complete, this project needs only the Click event procedures for the three
CommandButton controls. To reiterate, this is what the command buttons should do:

The Next button validates the data. If validation succeeds, the data is entered in
the worksheet, and the form is cleared for entry of the next address. If validation
fails, the form retains its data so the user can correct it as needed.
The Done button performs the same tasks as the Next button with one exception:
If validation succeeds, the form closes after the data is entered in the worksheet.
The Cancel button discards any data currently entered in the form and then closes
the form.
You may have noticed that the Done and Next buttons share a task, which is entering
the validated data in the worksheet. Whenever a task needs to be performed in more than
one situation, a programmer recognizes this as an opportunity for putting the required code
in a procedure. If you create a procedure that transfers the data from the form to the work-
sheet, this procedure can be called by both the Done and the Next button’s Click event
procedure.