HtmlObject.AttachEvent Method (String, EventHandler)

Silverlight

Attaches the specified .NET Framework event handler (EventHandler) to the specified event on the current Document Object Model (DOM) object.

Namespace:  System.Windows.Browser
Assembly:  System.Windows.Browser (in System.Windows.Browser.dll)

public bool AttachEvent(
	string eventName,
	EventHandler handler
)

Parameters

eventName
Type: System.String
A named event on the DOM object.
handler
Type: System.EventHandler
The method that handles the event.

Return Value

Type: System.Boolean
true if the event was successfully attached; otherwise, false.

ExceptionCondition
ArgumentException

eventName is an empty string.

ArgumentNullException

eventName is null.

-or-

handler is null.

The AttachEvent method returns a Boolean status value, which corresponds to the behavior in JavaScript.

When the event is raised, the sender parameter for the event handler is a reference to the HtmlObject on which AttachEvent was originally called.

Events can be sent into managed code from DOM elements or HTML objects (such as the window object) in two ways:

  • An element can immediately send an event into managed code.

  • An element can trigger an event that bubbles up through the DOM hierarchy until it reaches an element that is capable of sending the event into managed code.

Therefore, the sender parameter value can be different from the Source property value.

Cross-browser event naming issues are handled as follows:

  • For Internet Explorer: If eventName does not start with the string "on", the string is prepended to the event name (for example, "click" is changed to "onclick"). This enables developers who want to use Firefox naming conventions to attach their events automatically in Internet Explorer.

  • For other browsers: If eventName starts with the string "on", the string is removed from the event name to support browsers that have different naming conventions. (For example, "onclick" is changed to "click, and "onblur" is changed to "blur".)

No action is taken if the event that is specified in eventName does not exist.

To obtain a reference to the DOM element that raised the event, use the AttachEvent(String, EventHandler<HtmlEventArgs>) method.

Silverlight

Supported in: 5, 4, 3

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Community Additions

ADD
Show: