Expanding Selected Item height in ListBox

Question

Is there a way that I can have the SelectedItem\'s height larger than the rest of the items in a ListBox? This is what I have right now, yet it just acts as a normal listbox:

Answer 1

Your OnMeasureItem isn't doing anything while the DrawMode is OwnerDrawFixed. Change the mode to OwnerDrawVariable.

Unfortunately, the MeasureItem event only happens when the handle gets created, so here is a work-around:

public class BuddyListBox  : ListBox
{
  int thisIndex = -1;

  public BuddyListBox()
  {
    this.DrawMode = DrawMode.OwnerDrawVariable;
  }

  protected override void OnDrawItem(DrawItemEventArgs e)
  {
    if (this.Items.Count > 0)
    {
      if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
        e.Graphics.FillRectangle(SystemBrushes.Highlight, e.Bounds);
      else
        e.Graphics.FillRectangle(SystemBrushes.Window, e.Bounds);
      e.Graphics.DrawString(this.Items[e.Index].ToString(), e.Font, Brushes.Black, e.Bounds.Left, e.Bounds.Top);
      base.OnDrawItem(e);
    }
  }

  protected override void OnSelectedIndexChanged(EventArgs e)
  {
    base.OnSelectedIndexChanged(e);
    thisIndex = this.SelectedIndex;
    this.RecreateHandle();
  }

  protected override void OnMeasureItem(MeasureItemEventArgs e)
  {
    if (e.Index > -1)
    {
      if (e.Index == thisIndex)
        e.ItemHeight = 32;
      else
        e.ItemHeight = 16;
    }
    base.OnMeasureItem(e);
  }
}