ComponentChangedEventHandler Delegate

Reference

Definition

Namespace:: System.ComponentModel.Design

Assembly:: System.ComponentModel.TypeConverter.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Represents the method that will handle a ComponentChanged event.

public delegate void ComponentChangedEventHandler(System::Object ^ sender, ComponentChangedEventArgs ^ e);

public delegate void ComponentChangedEventHandler(object sender, ComponentChangedEventArgs e);

public delegate void ComponentChangedEventHandler(object? sender, ComponentChangedEventArgs e);

[System.Runtime.InteropServices.ComVisible(true)]
public delegate void ComponentChangedEventHandler(object sender, ComponentChangedEventArgs e);

type ComponentChangedEventHandler = delegate of obj * ComponentChangedEventArgs -> unit

[<System.Runtime.InteropServices.ComVisible(true)>]
type ComponentChangedEventHandler = delegate of obj * ComponentChangedEventArgs -> unit

Public Delegate Sub ComponentChangedEventHandler(sender As Object, e As ComponentChangedEventArgs)

Parameters

sender: Object

The source of the event.

e: ComponentChangedEventArgs

A ComponentChangedEventArgs that contains the event data.

Attributes: ComVisibleAttribute

Examples

This example demonstrates registering a ComponentChangedEventHandler and handling the ComponentChanged event.

public:
   void LinkComponentChangedEvent( IComponentChangeService^ changeService )
   {
      // Registers an event handler for the ComponentChanged event.
      changeService->ComponentChanged += gcnew ComponentChangedEventHandler(
         this, &ComponentChangedEventHandlerExample::OnComponentChanged );
   }

private:
   void OnComponentChanged( Object^ sender, ComponentChangedEventArgs^ e )
   {
      // Displays changed component information on the console.
      Console::WriteLine( "Type of the component that has changed: " +
         e->Component->GetType()->FullName );
      Console::WriteLine( "Name of the member of the component that has changed: " +
         e->Member->Name );
      Console::WriteLine( "Old value of the member: " + e->OldValue );
      Console::WriteLine( "New value of the member: " + e->NewValue );
   }

public void LinkComponentChangedEvent(IComponentChangeService changeService)
{
    // Registers an event handler for the ComponentChanged event.
    changeService.ComponentChanged += new ComponentChangedEventHandler(this.OnComponentChanged);            
}

private void OnComponentChanged(object sender, ComponentChangedEventArgs e)
{
    // Displays changed component information on the console.
    Console.WriteLine("Type of the component that has changed: "+e.Component.GetType().FullName);      
    Console.WriteLine("Name of the member of the component that has changed: "+e.Member.Name);            
    Console.WriteLine("Old value of the member: "+e.OldValue.ToString());
    Console.WriteLine("New value of the member: "+e.NewValue.ToString());
}

Public Sub LinkComponentChangedEvent(ByVal changeService As IComponentChangeService)
    ' Registers an event handler for the ComponentChanged event.
    AddHandler changeService.ComponentChanged, AddressOf Me.OnComponentChanged
End Sub

Private Sub OnComponentChanged(ByVal sender As Object, ByVal e As ComponentChangedEventArgs)
    ' Displays changed component information on the console.            
    Console.WriteLine(("Type of the component that has changed: " + e.Component.GetType().FullName))
    Console.WriteLine(("Name of the member of the component that has changed: " + e.Member.Name))
    Console.WriteLine(("Old value of the member: " + e.OldValue.ToString()))
    Console.WriteLine(("New value of the member: " + e.NewValue.ToString()))
End Sub

Remarks

When you create a ComponentChangedEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Handling and Raising Events.

A ComponentChanged event will not occur during the loading or unloading of a form because changes are expected during these operations.

Extension Methods

GetMethodInfo(Delegate)

Gets an object that represents the method represented by the specified delegate.

Applies to

Partajați prin