error when remove item from combobox

fugio huynh

hi all,
I have a piece of code, I can delete the first value but fails and give notice
InvalidArgument=Value of '0' is not valid for 'index'.
Parameter name: index

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Private Sub ComboBox1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyDown

     If ComboBox1.Items.Count > 0 Then

        If e.KeyCode = Keys.Delete Then

             ComboBox1.Items.Remove(ComboBox1.SelectedItem)

'or

              'ComboBox1.Items.RemoveAt(ComboBox1.SelectedIndex)

       End If

    End If

End Sub

thank help !

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Incidentally, if you wanted to get rid of the last remaining item in the combobox whether it was selected or not, then you could try this code:

Private Sub ComboBox1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyDown

If e.KeyCode = Keys.Delete Then
If comboBox1.SelectedIndex > -1 Then
comboBox1.Items.RemoveAt(comboBox1.SelectedIndex)
ElseIf comboBox1.Items.Count = 1 Then
comboBox1.Items.Clear()
End If
End If

End Sub
Vulpes12y ago
Is it any better if you recode it like this:

Private Sub ComboBox1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyDown

If ComboBox1.SelectedIndex > -1 Then
If e.KeyCode = Keys.Delete Then
ComboBox1.Items.RemoveAt(ComboBox1.SelectedIndex)
End If
End If

End Sub
Shweta Lodha12y ago
I can't see this check in your code. Can you please paste your updated code here ?
fugio huynh12y ago
I declare If ComboBox1.SelectedIndex > 0 Then Can not delete the first value
Shweta Lodha12y ago
Hi,
When you will delete first item and then press the delete again, at that time your selected item will be null. Hence selectedIndex will be -1.

Unfortunately you will land up with an exception.