Question

I’m trying to format the length of a DataGridViewComboBoxColumn based on the length of the longest string in the comboBox. Here is the code I currently have, but it only formats the DataGridViewComboBoxColumn based on the users previous selection in the comboBox.

Is there a way to have the DataGridViewComboBoxColumn at the length of the longest string in the comboBox?

Here is my code:

Private Sub comboTest_SelectionChangeCommitted(ByVal sender As Object, ByVal e As EventArgs) Handles comboTest.SelectionChangeCommitted

    Dim senderComboBox As ComboBox = CType(sender, ComboBox)

    'Change the length of the text box depending on what the user has
    'selected and committed using the SelectionLength property.
    If (comboTest.SelectionLength > 0) Then
        comboTest.Width = comboTest.SelectionLength * CType(Me.comboTest.Font.SizeInPoints, Integer)
        comboTest.SelectedValue = comboTest.SelectedText
    End If
End Sub

Answer 1

It seems like you just need to calculate the longest string in the ComboBox. Assuming that it’s just a collection of String values being displayed you can do the following.

Dim length = 0
For Each item As String in comboTest.Items 
  length = Max(length, item.Length)
Next

If length > 0 Then
  comboTest.Width = length * CType(Me.comboTest.Font.SizeInPoints, Integer)
  comboTest.SelectedValue = comboTest.SelectedText
End If