CheckedListBox Action ItemCheck to remove items?

When a box that is checked is unchecked I want to remove that item. The trouble is check/unchecking seems to happen after the ItemCheck method is called. So, when I remove an item that messes up the e.Index so it does the check/uncheck on the item after the one I remove or throws an error if it is the last one.

I found this: Getting the ListView ItemCheck to stop! which has the tip of resetting the e.NewValue which partially works, but it still throws an error when I remove the last item.

The reason I have not simply used one of the mouse events is that I want keyboard navigation to still be possible just in case.

Here is the code I have now.

private void checked_ItemCheck(object sender, ItemCheckEventArgs e)
        {
            if (e.NewValue == CheckState.Unchecked)
         开发者_StackOverflow   {
                checked.Items.RemoveAt(e.Index);
                e.NewValue = CheckState.Checked;
            }
        }

Thanks for the help

It sounds like the only problem you're still experiencing is the call to e.NewValue after you remove the last item, right? If that's the case, try this:

private void checked_ItemCheck(object sender, ItemCheckEventArgs e)
{
    if (e.NewValue == CheckState.Unchecked)
    {
        checked.Items.RemoveAt(e.Index);

        // If there are no items left, skip the CheckState.Checked call
        if (checked.Items.Count > 0)
        {
            e.NewValue = CheckState.Checked;
        }             
    }
} 

UPDATE

Ok - I got it to work, though I'm not sure how pretty it is. I used the SelectedIndexChanged event:

private void checked_SelectedIndexChanged(object sender, EventArgs e)
{

    CheckedListBox clb = (CheckedListBox)sender;
    int index = clb.SelectedIndex;

    // When you remove an item from the Items collection, it fires the SelectedIndexChanged
    // event again, with SelectedIndex = -1.  Hence the check for index != -1 first, 
    // to prevent an invalid selectedindex error
    if (index != -1 && clb.GetItemCheckState(index) == CheckState.Unchecked)
    {
        clb.Items.RemoveAt(index);
    }
}

I've tested this in VS 2010 and it works.