c# - Dynamically changing the text of items in a Winforms ComboBox

Question

I have a Winforms ComboBox that contains instances of a custom class. When the items are first added to the Items collection of the ComboBox, the ToString method is call on each of them.

However when the user changes the language the application is running in, the result of the ToString method changes.

Therefore how can I get the ComboBox to call the ToString method on all items again without having to remove all items from the ComboBox and adding them back in?

Answer 1

Thanks svick, RefreshItems() work, however as it is protected (so can only be called by a subclass) I had to do

public class RefreshingComboBox : ComboBox
{
    public new void RefreshItem(int index)
    {
        base.RefreshItem(index);
    }

    public new void RefreshItems()
    {
        base.RefreshItems();
    }
}

I have just had to do the same for a ToolStripComboBox, however it was a bit harder as you can not subclass the Combro box it contains, I did

public class RefreshingToolStripComboBox : ToolStripComboBox
{
    // We do not want "fake" selectedIndex change events etc, subclass that overide the OnIndexChanged etc
    // will have to check InOnCultureChanged them selfs
    private bool inRefresh = false;
    public bool InRefresh { get { return inRefresh; } }

    public void Refresh()
    {
        try
        {
            inRefresh = true;

            // This is harder then it shold be, as I can't get to the Refesh method that
            // is on the embebed combro box.
            //
            // I am trying to get ToString recalled on all the items
            int selectedIndex = SelectedIndex;
            object[] items = new object[Items.Count];
            Items.CopyTo(items, 0);

            Items.Clear();

            Items.AddRange(items);
            SelectedIndex = selectedIndex;
        }
        finally
        {
            inRefresh = false;
        }
    }

    protected override void OnSelectedIndexChanged(EventArgs e)
    {
        if (!inRefresh)
        {
            base.OnSelectedIndexChanged(e);
        }
    }
}

I had to do the same trip to stop unwanted events for the normal CombroBox, by overriding OnSelectedValueChanged, OnSelectedItemChanged and OnSelectedIndexChanged, as the code is the same as for the ToolStripComboBox I have not included it here.