CollectionChangeEventArgs.Element 属性

定义

获取包含更改的集合实例。Gets the instance of the collection with the change.

public:
 virtual property System::Object ^ Element { System::Object ^ get(); };
public virtual object Element { get; }
member this.Element : obj
Public Overridable ReadOnly Property Element As Object

属性值

Object

表示包含更改的集合实例的 Object;如果刷新集合,则为 nullAn Object that represents the instance of the collection with the change, or null if you refresh the collection.

示例

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,事件处理程序报告事件的发生 AutoCompleteStringCollection.CollectionChangedIn the example, an event handler reports on the occurrence of the AutoCompleteStringCollection.CollectionChanged 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 MessageBox.Show Console.WriteLine 将消息替换为多行或将其追加到多行 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的类型的实例的项目中 AutoCompleteStringCollection AutoCompleteStringCollection1To run the example code, paste it into a project that contains an instance of type AutoCompleteStringCollection named AutoCompleteStringCollection1. 然后,确保事件处理程序与事件相关联 AutoCompleteStringCollection.CollectionChangedThen ensure that the event handler is associated with the AutoCompleteStringCollection.CollectionChanged event.

private void AutoCompleteStringCollection1_CollectionChanged(Object sender, CollectionChangeEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "Action", e.Action );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Element", e.Element );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "CollectionChanged Event" );
}
Private Sub AutoCompleteStringCollection1_CollectionChanged(sender as Object, e as CollectionChangeEventArgs) _ 
     Handles AutoCompleteStringCollection1.CollectionChanged

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "Action", e.Action)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Element", e.Element)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"CollectionChanged Event")

End Sub

适用于

另请参阅