DependencyObject.AddHandler Method

Adds a handler for an event of a DependencyObject.

Namespace:  System.Workflow.ComponentModel
Assembly:  System.Workflow.ComponentModel (in System.Workflow.ComponentModel.dll)

public void AddHandler(
	DependencyProperty dependencyEvent,
	Object value
)

Parameters

dependencyEvent
Type: System.Workflow.ComponentModel.DependencyProperty

The DependencyProperty.

value
Type: System.Object

The Object that represents the value of this property. In this case, a Delegate type.

ExceptionCondition
ArgumentNullException

Either of the arguments is a null reference (Nothing in Visual Basic).

ArgumentException

Value is of incorrect Type.

ArgumentException

The dependencyEvent represents a non-event DependencyProperty.

When you create a delegate, you identify the method that handles the event. To associate the event with your event handler, add an instance of the delegate to the event. Unless you remove the delegate, the event handler is called whenever the event occurs. Multiple delegates can be added to handle an event. For more information about event-handler delegates, see Events and Delegates.

Handlers are added and removed using the following code. This code example is part of the Send E-mail SDK sample and is from the SendMailActivity.cs file. For more information, see Send E-mail Activity Sample.

        #region Public Events

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        [Description("The SendingEmail event is raised before an email is sent through SMTP.")]
        [Category(EventsCategory)]
        [Browsable(true)]
        public event EventHandler SendingEmail
        {
            add
            {
                base.AddHandler(SendEmailActivity.SendingEmailEvent, value);
            }
            remove
            {
                base.RemoveHandler(SendEmailActivity.SendingEmailEvent, value);
            }
        }

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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