ListView.ItemDrag 事件


在用户开始拖动项时发生。Occurs when the user begins dragging an item.

 event System::Windows::Forms::ItemDragEventHandler ^ ItemDrag;
public event System.Windows.Forms.ItemDragEventHandler ItemDrag;
member this.ItemDrag : System.Windows.Forms.ItemDragEventHandler 
Public Custom Event ItemDrag As ItemDragEventHandler 


下面的代码示例演示如何使用此成员。The following code example demonstrates the use of this member. 在此示例中,事件处理程序报告 @no__t 的事件发生。In the example, an event handler reports on the occurrence of the ItemDrag event. 此报表可帮助你了解何时发生事件,并可帮助你进行调试。This report helps you to learn when the event occurs and can assist you in debugging. 若要报告多个事件或频繁发生的事件,请考虑将 @no__t 0 替换为 Console.WriteLine,或将消息附加到多行 TextBoxTo report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.

若要运行示例代码,请将其粘贴到包含名为 @no__t ListView 类型实例的项目中。To run the example code, paste it into a project that contains an instance of type ListView named ListView1. 然后,确保事件处理程序与 @no__t 0 事件关联。Then ensure that the event handler is associated with the ItemDrag event.

private void ListView1_ItemDrag(Object sender, ItemDragEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "Button", e.Button );
messageBoxCS.AppendFormat("{0} = {1}", "Item", e.Item );
MessageBox.Show(messageBoxCS.ToString(), "ItemDrag Event" );
Private Sub ListView1_ItemDrag(sender as Object, e as ItemDragEventArgs) _ 
     Handles ListView1.ItemDrag

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "Button", e.Button)
    messageBoxVB.AppendFormat("{0} = {1}", "Item", e.Item)
    MessageBox.Show(messageBoxVB.ToString(),"ItemDrag Event")

End Sub


当用户开始拖动项时发生 @no__t 0 事件。The ItemDrag event occurs when the user begins dragging an item. 通常情况下,@no__t 0 事件的事件处理程序通过调用 Control.DoDragDrop 方法来执行拖动任务。Typically the event handler for the ItemDrag event performs the task of dragging by calling the Control.DoDragDrop method. 你可以使用此事件来执行将项拖入和移出应用程序的 @no__t 0 控件所需的任务。You can use this event to perform the tasks necessary to drag items into and out of your application's ListView control.

有关处理事件的详细信息,请参阅处理和引发事件For more information about handling events, see Handling and Raising Events.