Textbox Enter event fires twice

[brosmi]

I have 3 textboxes on a form (txt1,txt2,txt3)

I am using an event handler (EnterHandler) to handle each textbox's Enter
event for Validation.

In the EnterHandler for txt3 I will validate that txt2 contains a Y and if not I will set the focus back to txt2.

The focus goes to txt2 but why does the Enter event get invoked twice for txt2. ?


Private Sub EnterHandler(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt1.Enter, txt2.Enter, txt3.Enter
Debug.Print("ENTER " & sender.name)
Select Case sender.name
Case "txt3"
If txt2.Text <> "Y" Then
MsgBox("txt2 must be Y")
txt2.Focus()
End If
End Select
End Sub

Immediate Window Output

ENTER txt1
ENTER txt2
ENTER txt3
ENTER txt2
ENTER txt2

 

[JohnH]

bc you focused it, the Enter event documentation is very clear about this. Validating event would be my first choice if I wanted to validate something.

 

[brosmi]

When I set the focus to txt2 in the EnterHandler procedure it triggers the EnterHandler for txt2 twice. Surely it should only trigger it once.

Here is a brief background to this.

I have developed many screens over the years in VB6 which must validate data according to the following rules.

1) Only validate a textbox as I move forward through controls. (i.e. tab forward or click into another textbox with a higher tabindex).

2) No validation on a textbox if I enter garbage and click or tab to an earlier control.

3) If I move from textbox2 to textbox7 then I must validate all textboxes in between the two controls. (i.e. from 2 to 6). If validation fails on any of these
textboxes I will display a message and set the focus to the offending textbox.

In VB6 I used the gotfocus event to handle my validation. One reason is that I know whether the user has just moved forwards or backwards.

In vb.net I have tried using Gotfocus & Enter events. The Enter event works other than triggering the Enter event twice if I issue a .Focus statement to set the focus to a textbox which has failed validation.

The Gotfocus event continues to set the focus to the textbox the user tabbed to or clicked to even I call a .focus statement to Setfocus to another textbox.