Does Setting ListBox.ListIndex Invoke Listbox_Click Event?

[f64]

Does setting the ListBox.ListIndex value automatically invoke the Listbox_Click event? In a section of code outside of the ListBox_Click event I am setting the value of ListBox.ListIndex. After this is executed, changes are made to the ListBox indicating the ListBox_Click event had been invoked. Does setting the ListIndex number also run ListBox_Click? If so, why?

 

[RoyVidar]

For native Access listbox controls it does, so there something like this

[tt]me!lstMyList.selected(N) = True[/tt]

can be used in stead (N - index of the item you wish to select) - I think the same syntax should work also for MSForms listbox controls.

Roy-Vidar

 

[rmikesmith]

f64,

Yes, it appears to be a side-effect. If you (or rather your code) set the ListIndex to the same value as it is currently, the Click event is not triggered.

I usually handle these situations using a boolean flag that is checked on entry to an event handler where I have code. If this boolean is set, I exit the handler. Example (say in a Userform module):

Dim IgnoreEvent As Boolean

Private Sub MySub()
' This sub will change ListBox.ListIndex

  IgnoreEvent = True
  ...
  ListBox.ListIndex = 3
  ...
  IgnoreEvent = False
End Sub

Private Sub ListBox_Click()
  If IgnoreEvent Then Exit Sub
End Sub

The net effect is that any additional code in the Click handler will not run as a result of other code changing the ListIndex property.

HTH
Mike

 

[fumei]

Yes, it does. Not only that but it fires the _Change event as well, in fact first.

For example:

Private Sub UserForm_Initialize()
ComboBox1.AddItem "zero"
ComboBox1.AddItem "one"
ComboBox1.AddItem "two"
ComboBox1.AddItem "three"
ComboBox1.AddItem "four"
ComboBox1.AddItem "five"
ComboBox1.ListIndex = 0
End Sub

fires Combobox1_Change, THEN
fires Combobox1_Click, THEN
finally display the UserForm

You can easily see this order by testing with a command button that:

Private Sub CommandButton1_Click()
' make a change to the ListIndex
ComboBox1.ListIndex = InputBox("index number?")
End Sub

' now make so you get DIFFERENT result for _Change and _Click

Private Sub ComboBox1_Change()
MsgBox "Listindex is " & ComboBox1.ListIndex
End Sub

Private Sub ComboBox1_Click()
MsgBox "Listindex is " & ComboBox1.ListIndex + 1
End Sub

Now I understand why the _Change event fires. After all, the state of the combobox IS changed. I am not why it is required to fire _Click - as the control is NOT clicked.

You can worked around this by making a global variable that is set in the _Change event, and checked in the _Click event. That way, if you do not want both to fire you can do so.

Gerry

 

[fumei]

Darn, some people are so FAST! Mike got in there saying essentially the same thing.

Gerry