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IHTMLWindow2::onbeforeunload Property

Sets or retrieves a pointer to the event handler function associated with the onbeforeunload event.

Syntax

HRESULT IHTMLWindow2::get_onbeforeunload(VARIANT *p);
HRESULT IHTMLWindow2::put_onbeforeunload(VARIANT v);

Parameters

  • p
    Pointer to a variable of type VARIANT of type VT_DISPATCH that receives the IDispatch interface of an object with a default method that is invoked when the event occurs.
  • v
    VARIANT of type VT_DISPATCH that specifies the IDispatch interface of an object with a default method that is invoked when the event occurs.

Return Value

Returns S_OK if successful, or an error value otherwise.

Remarks

The handler for this event can return a string that prompts the user to cancel or continue the unload operation. The user is then prompted with a dialog box that shows two buttons, along with the returned string:

  • Ok — the unload operation proceeds.
  • Cancel — the navigation unload is cancelled.

See Also

IHTMLElement2::attachEvent, IHTMLWindow3::attachEvent