This method causes the application to connect to the ArcIMS server and retrieve service information about the map service. Once called, properties of the MapService object may be accessed and methods to create a MapView or LayoutView may be used.

This method is required only when the MapService is created with the initializeOnConstruction parameter set to false.

Initialize may be called again to retrieve a more complete set of information about the map service. For example, if during construction of MapService, the LoadFields property of InitializationParameters object is set to false, you can later call Initialize with InitializationParameters.LoadFields set to true so that field information is retrieved. You would then need to construct a new MapView so that this information is passed to the MapView. A previously created MapView object would not contain the fields information.

Reference