While the preferred way to insert items is to set Items.All, and set all the items at once, there are times when you may wish to insert each item one at a time. To help with the performance of this, it is desirable to prevent the ListBox from painting during these operations. This method, along with EndUpdate, is the preferred way of doing this. Don't forget to call EndUpdate when you're done, or else the ListBox won't paint properly afterwards.
[Visual Basic] Public Sub BeginUpdate() [C#] public void BeginUpdate(); [C++] public: void BeginUpdate(); [JScript] public function BeginUpdate();