ILoggable

System.Windows.Forms.ListBox bug with BeginUpdate()/EndUpdate()

Came across an annoying bug with ListBox. If you use BeginUpdate() and EndUpdate() and only add a single item to a cleared Item collection, then that Item does not show up on Refresh. However if you leave the BeginUpdate()/EndUpdate() out, it works fine, resulting in a need for code like this:

listBox.Items.Clear();
if( itemList.Count > 1 )
{
    //only use the Begin/End cycle if we have more than one item
    itemList.BeginUpdate();
}
foreach( object item in itemList )
{
    listBox.Items.Add(item);
}
if( group.Strings.Count > 1 )
{
    //only use the Begin/End cycle if we have more than one item
    mStrings.EndUpdate();
}
listBox.Refresh();

posted by ether @ 4:21 PM