How to clear userform textbox without calling the _Change function? - vba

Question

I have a userform in Excel with textboxes meant for numeric data only. I want to clear the textbox when it detects bad entry and gives an error message, but I don't want to have the textbox's _Change function called again or else the message pops up twice because I change the text to "". I didn't see a built in clear function.. is there a better way to do this?
Private Sub txtbox1_Change()
txt = userform.txtbox1.Value
If Not IsNumeric(txt) Then
disp = MsgBox("Please only enter numeric values.", vbOKCancel, "Entry Error")
txtbox1.Text = ""
End If
End Sub

Answer 1

A simple way to achieve this is to use the _Exit() Function:
Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
If Not IsNumeric(TextBox1.Value) Then
MsgBox "Please only enter numeric values.", vbCritical, "Error"
End If
End Sub
This triggers as soon as the text box looses Focus.

Answer 2

prevent user from typing Alpha chars:
Private Sub TextBox1_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
Select Case KeyAscii
Case Asc("0") To Asc("9")
Case Asc("-")
If Instr(1,Me.TextBox1.Text,"-") > 0 Or Me.TextBox1.SelStart > 0 Then
KeyAscii = 0
End If
Case Asc(".")
If InStr(1, Me.TextBox1.Text, ".") > 0 Then
KeyAscii = 0
End If
Case Else
KeyAscii = 0
End Select
End Sub
Hope this helps!
-Hugues

Answer 3

You can do this way, as shown here
Private Sub TextBox1_Change()
OnlyNumbers
End Sub
Private Sub OnlyNumbers()
If TypeName(Me.ActiveControl) = "TextBox" Then
With Me.ActiveControl
If Not IsNumeric(.Value) And .Value <> vbNullString Then
MsgBox "Sorry, only numbers allowed"
.Value = vbNullString
End If
End With
End If
End Sub

Answer 4

You can add this line at the very beginning
sub txtbox1_Change()
If txtbox1.Text = "" Or txtbox1.Text = "-" Then Exit Sub '<~~~
Alternatively, I found this even shorter and interesting:
Private Sub txtbox1_Change()
If Not IsNumeric(txtbox1.Text & "0") Then
disp = MsgBox("Please only enter numeric values.", vbOKCancel, "Entry Error")
txtbox1.Text = ""
End If
End Sub
The interesting part is that it accepts to enter things like ".2", "-3.2", and also "5e3", the last case being not allowed by the other methods!
Turning it into a while loop can remove only the last bad typed character(s):
Private Sub txtbox1_Change()
t = txtbox1.Text
Do While t <> "" And Not IsNumeric(t) And Not IsNumeric(t & "0")
t = Mid(t, 1, Len(t) - 1)
Loop
txtbox1.Text = t
End Sub

Answer 5

Seems since there is nothing built in that can do what I want, this would be the simplest way to handle the problem:
Private Sub txtbox1_Change()
txt = userform.txtbox1.Value
If (Not IsNumeric(txt)) And (txt <> "") Then
disp = MsgBox("Please only enter numeric values.", vbOKCancel, "Entry Error")
txtbox1.Text = ""
End If
End Sub

Answer 6

Declare a global boolean and at the beginning of each sub, add an if statement which exits the sub if the boolean is true. When you get an error message, set the value to true, and nothing will happen. Then set it to false again.
Dim ufEventsDisabled As Boolean
Private Sub txtbox1_Change()
'repeat the following line everywhere that you don't want to update
if ufeventsdisabled then exit sub
txt = userform.txtbox1.Value
If Not IsNumeric(txt) Then
disp = MsgBox("Please only enter numeric values.", vbOKCancel, "Entry Error")
ufeventsdisabled = true
txtbox1.Text = ""
ufeventsdisabled = false
End If
End Sub
*Credit goes to mikerickson from mrexcel.com

Answer 7

You can't stop the _Changed event from firing. I would advise you to back up a couple of steps in your design and ask if you can get the job done without having to clear it in the first place. In FoxPro we would set the 'format' to 9999.99 and it would automatically prevent users from typing alpha characters, but I think that particular field was unique to FP. You can hook the _Changed event and perform your own validation there. I would suggest not filtering individual key strokes, but validating the whole value each time it's changed.
If Text1.Value <> str(val(Text1.Value)) Then
Text1.Value = previousValue
EndIf
... which will require keeping a backup variable for the previous value, but I'm sure you can figure that out. There may be certain edge cases where VB's string-number conversion functions don't exactly match, like exponential notation as you mentioned, so you may need a more sophisticated check than that. Anyway, this will make it impossible to even enter a bad value. It also provides a better user experience because the feedback is more immediate and intuitive. You may notice that the value is being changed inside the _Changed event, which should raise a knee jerk red flag in your mind about infinite loops. If you do this, make sure that your previous value has already been validated, keeping in mind that the initial value will be an empty string. As such, the recursive call will skip over the If block thus terminating the loop. In any case, what you would consider "better" may differ depending on who you ask, but hopefully I've given you some food for thought.