Will be called at startup of the control to sets the context for the task.

Method that is called when user clicks "Send" button. Can e.g. be used to invoke event on custom service

If the page loaded beside Task (that is in edit panel/mode) has changed since the control was loaded then this method is called before InvokeEvent is called (it is called before Page.Validate as well). This means the user has done some browsing in edit panel, e.g. may have shifted a page version.

Gets the text the invoke button should have. If null or string.Empty is returned, default text "Send" (language dependent) is used