我无法使我的 ListView
控件触发 GiveFeedback
事件。
以下代码仅用于测试,它从事件中更新文本标签,以查看哪些事件何时触发。当拖动一个项目时,label1
更新,当放置项目时,label3
更新。但为什么 label2
从未更新?我错过了什么吗?
public Form1()
{
InitializeComponent();
listView1.ItemDrag += new ItemDragEventHandler(listView1_ItemDrag);
listView1.DragDrop += new DragEventHandler(listView1_DragDrop);
listView1.DragEnter += new DragEventHandler(listView1_DragEnter);
listView1.DragOver += new DragEventHandler(listView1_DragOver);
listView1.GiveFeedback += new GiveFeedbackEventHandler(listView1_GiveFeedback);
}
private void listView1_ItemDrag(object sender, ItemDragEventArgs e)
{
DoDragDrop(e.Item, DragDropEffects.All);
}
private void listView1_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Move;
}
private void listView1_DragOver(object sender, DragEventArgs e)
{
label1.Text = "DragOver " + DateTime.Now.ToString();
}
private void listView1_GiveFeedback(object sender, GiveFeedbackEventArgs e)
{
label2.Text = "GiveFeedback " + DateTime.Now.ToString();
}
private void listView1_DragDrop(object sender, DragEventArgs e)
{
label3.Text = "DragDrop " + DateTime.Now.ToString();
}