AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
BMBaseTabController *tab = (BMBaseTabController *)delegate.window.rootViewController;
tab.selectedIndex = 1;
拿到tabbar 單例,讓當前選中變成 要跳轉的controller個數
AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
BMBaseTabController *tab = (BMBaseTabController *)delegate.window.rootViewController;
tab.selectedIndex = 1;
拿到tabbar 單例,讓當前選中變成 要跳轉的controller個數