Szerkesztés

Megosztás a következőn keresztül:

CollectionChangeEventArgs.Action Property

  • Reference

Definition

Namespace:
System.ComponentModel
Assembly:
System.ComponentModel.TypeConverter.dll
Assembly:
System.dll
Assembly:
netstandard.dll
Package:
System.ComponentModel.TypeConverter v4.3.0
Source:
CollectionChangeEventArgs.cs
Source:
CollectionChangeEventArgs.cs
Source:
CollectionChangeEventArgs.cs

Gets an action that specifies how the collection changed.

public:
 virtual property System::ComponentModel::CollectionChangeAction Action { System::ComponentModel::CollectionChangeAction get(); };
public virtual System.ComponentModel.CollectionChangeAction Action { get; }
member this.Action : System.ComponentModel.CollectionChangeAction
Public Overridable ReadOnly Property Action As CollectionChangeAction

Property Value

CollectionChangeAction

One of the CollectionChangeAction values.

Examples

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the AutoCompleteStringCollection.CollectionChanged event. This report helps you to learn when the event occurs and can assist you in debugging. 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.

To run the example code, paste it into a project that contains an instance of type AutoCompleteStringCollection named AutoCompleteStringCollection1. 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

Remarks

This property can have one of the following values:

Action Property value
An element was added to the collection CollectionChangeAction.Add
An element was removed from the collection CollectionChangeAction.Remove
The collection was completely changed CollectionChangeAction.Refresh

Applies to

See also