When the IOS switch Tab, the Baidu map will appear flashing a bit

-(void) Viewwillappear: (BOOL) animated{[Super viewwillappear:animated];    [Mobclick beginlogpageview:@ "Wrappermainviewcontroller"]; [_mapview Viewwillappear]; Note After removing the Toggle tab Map Flash problem _mapview.delegate = self;    Remember that you need to set nil here, otherwise affect the memory release}-(void) Viewwilldisappear: (BOOL) animated{[Super viewwilldisappear:animated];        [Mobclick endlogpageview:@ "Wrappermainviewcontroller"];    [_mapview Viewwilldisappear]; _mapview.delegate = nil; When not in use, place nil}

/** * When Mapview is about to be called explicitly, restore the Mapview state that was stored before. */-(void) viewwillappear;/** * Called when Mapview is about to be hidden, storing the state of the current Mapview. */-(void) viewwilldisappear;/** * Forced flush Mapview */-(void) Mapforcerefresh;

When the IOS switch Tab, the Baidu map will appear flashing a bit