c# – 在OwnerDraw模式下ListBox DrawItem HotLight状态？

DrawItemState.HotLight仅适用于所有者绘制的菜单,而不适用于列表框.对于ListBox,您必须自己跟踪项目：

public partial class Form1 : Form
{
  private int _MouseIndex = -1;

  public Form1()
  { InitializeComponent(); }

  private void listBox1_DrawItem(object sender,DrawItemEventArgs e)
  {
    Brush textBrush = SystemBrushes.WindowText;

    if (e.Index > -1)
    {
      if (e.Index == _MouseIndex)
      {
        e.Graphics.FillRectangle(SystemBrushes.HotTrack,e.Bounds);
        textBrush = SystemBrushes.HighlightText;
      }
      else
      {
        if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
        {
          e.Graphics.FillRectangle(SystemBrushes.Highlight,e.Bounds);
          textBrush = SystemBrushes.HighlightText;
        }
        else
          e.Graphics.FillRectangle(SystemBrushes.Window,e.Bounds);
      }
      e.Graphics.DrawString(listBox1.Items[e.Index].ToString(),e.Font,textBrush,e.Bounds.Left + 2,e.Bounds.Top);
    }
  }

  private void listBox1_MouseMove(object sender,MouseEventArgs e)
  {
    int index = listBox1.IndexFromPoint(e.Location);
    if (index != _MouseIndex)
    {
      _MouseIndex = index;
      listBox1.Invalidate();
    }
  }

  private void listBox1_MouseLeave(object sender,EventArgs e)
  {
    if (_MouseIndex > -1)
    {
      _MouseIndex = -1;
      listBox1.Invalidate();
    }
  }
}