我在我的WinForms应用程序中使用OwnerDrawFixed作为DrawMode用于自定义ListBox控件.
当用户将鼠标悬停在列表框项目上时,我希望重新绘制ListBoxItem的背景(或执行其他操作),即在MouseMove …
DrawItemState.HotLight永远不适用于ListBox,所以我想知道如何模拟它,如何解决这个问题.
解决方法
我花了两年时间为你找到答案,但这里是：
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();
}
}
}