Question

I have a requirement to filter continuous form using string entered or selected from combobox. Below is code I am attempting to use to capture the filter string. What happens is that when text is typed into the list, rather than the string being caught in the back, an error is instead thrown indicating that the combo-box is Null.

Where do I put this functionality? I am thinking of just adding the code to the Combobox_Selected event but that would not give user’s the ability to type arbitrary keywords with which to further filter the content of the form with.

Private Sub txtUSPSKeySearch_Change()
On Error GoTo Err_txtUSPSKeySearch_Change
Dim searchStr As String

               searchStr = txtUSPSKeySearch.Value
                  If (Not IsNull(searchStr) And Len(searchStr) > 1) Then

                  Else

                    ' Move the cursor to the end of the combo box.
  Me.txtUSPSKeySearch.SetFocus
  Me.txtUSPSKeySearch.SelStart = Len(Me.txtUSPSKeySearch.Value)
                 End If

'Error Handling
Exit_txtUSPSKeySearch_Change:
    Exit Sub
Err_txtUSPSKeySearch_Change:
    If Err.Number = 5 Then
         MsgBox "You must make a selection(s) from the list" _
               , , "Selection Required !"
        Resume Exit_txtUSPSKeySearch_Change
    Else
        'Write out the error and exit the sub
        MsgBox Err.Description
        Resume Exit_txtUSPSKeySearch_Change
    End If
End Sub

Answer 1

“What happens is that when text is typed into the list, rather than the string being caught in the back, an error is instead thrown indicating that the combo-box is Null.“

You declared that searchStr must be String data type:

Dim searchStr As String

When txtUSPSKeySearch is Null, this assignment will fail because Null is not string data type.

searchStr = txtUSPSKeySearch.Value

You could use the Nz() function to give searchStr an empty string when txtUSPSKeySearch is Null:

searchStr = Nz(Me.txtUSPSKeySearch.Value, vbNullString)

Then you could change the If statement from this …

If (Not IsNull(searchStr) And Len(searchStr) > 1) Then

to this …

If Len(searchStr) = 0 Then

You’re doing all this from the txtUSPSKeySearch change event. Consider using the before update event to validate the value, and the after update event to do whatever else (apply the filter condition?) you want to do with a valid value.