CollectionChangeEventArgs 类

定义

CollectionChanged 事件提供数据。Provides data for the CollectionChanged event.

public ref class CollectionChangeEventArgs : EventArgs
public class CollectionChangeEventArgs : EventArgs
type CollectionChangeEventArgs = class
    inherit EventArgs
Public Class CollectionChangeEventArgs
Inherits EventArgs
继承
CollectionChangeEventArgs

示例

下面的代码示例演示如何使用此类型。The following code example demonstrates the use of this type. 在此示例中,事件处理程序报告 AutoCompleteStringCollection.CollectionChanged 事件的发生。In 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,请考虑将 MessageBox.Show 替换为 Console.WriteLine 或将消息附加到多行 TextBox中。To 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 AutoCompleteStringCollection1AutoCompleteStringCollection 类型实例的项目中。To 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 AutoCompleteStringCollection.CollectionChanged 事件关联。Then 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

注解

更改集合中的项(例如,通过向集合添加元素或从集合中移除元素)时,会引发 CollectionChanged 事件。A CollectionChanged event is raised when you change which items are in a collection, for example, by adding an element to a collection or removing an element from the collection. 当单个元素更改其值时,不会引发此事件。This event is not raised when an individual element changes its value.

构造函数

CollectionChangeEventArgs(CollectionChangeAction, Object)

初始化 CollectionChangeEventArgs 类的新实例。Initializes a new instance of the CollectionChangeEventArgs class.

属性

Action

获取指定集合如何更改的操作。Gets an action that specifies how the collection changed.

Element

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

方法

Equals(Object)

确定指定对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回表示当前对象的字符串。Returns a string that represents the current object.

(继承自 Object)

适用于

另请参阅