public static bool IsBusy {get;}

// The application is considered busy if a task is currently running on the main worker thread or any 
// pane or dock pane reports that it is busy or intiializing.   

// Many Pro styles (such as Esri_SimpleButton) ensure that a button is disabled when FrameworkApplication.IsBusy is true
// You would use this property to bind to the IsEnabled property of a control (such as a listbox) on a dockpane or pane in order
// to disable it from user interaction while the application is busy. 
bool isbusy = FrameworkApplication.IsBusy;