Public Sub AddToMyListBox()
    ' Stop the ListBox from drawing while items are added.
    listBox1.BeginUpdate()

    ' Loop through and add five thousand new items.
    Dim x As Integer
    For x = 1 To 4999
        listBox1.Items.Add("Item " & x.ToString())
    Next x
    ' End the update process and force a repaint of the ListBox.
    listBox1.EndUpdate()
End Sub

public void AddToMyListBox()
{
   // Stop the ListBox from drawing while items are added.
   listBox1.BeginUpdate();

   // Loop through and add five thousand new items.
   for(int x = 1; x < 5000; x++)
   {
      listBox1.Items.Add("Item " + x.ToString());   
   }
   // End the update process and force a repaint of the ListBox.
   listBox1.EndUpdate();
}

void AddToMyListBox()
{
   // Stop the ListBox from drawing while items are added.
   listBox1->BeginUpdate();

   // Loop through and add five thousand new items.
   for ( int x = 1; x < 5000; x++ )
   {
      listBox1->Items->Add( String::Format( "Item {0}", x ) );
   }
   listBox1->EndUpdate();
}

public void AddToMyListBox()
{
    // Stop the ListBox from drawing while items are added.
    listBox1.BeginUpdate();

    // Loop through and add five thousand new items.
    for (int x = 1; x < 5000; x++) {
        listBox1.get_Items().Add(("Item" + (new Integer(x)).ToString()));
    }

    // End the update process and force a repaint of the ListBox.
    listBox1.EndUpdate();
} //AddToMyListBox

function AddToMyListBox(){
    // Stop the ListBox from drawing while items are added.
    listBox1.BeginUpdate()

    // Loop through and add five thousand new items.
    for(var x = 0; x < 5000; x++)
        listBox1.Items.Add("Item " + x.ToString())
    // End the update process and force a repaint of the ListBox.
    listBox1.EndUpdate()
}