项目结构分析、rootViewController切换

项目结构分析

底部导航UITabBarController+导航栏UINavigationController结构的iOS项目分析

1、退出登录切换rootViewController时、必须要dismiss掉present出来的控制器、要不然控制器不会释放、造成内存泄漏，push出来的就不需要处理、切换就会释放

UIWindow *keyWindow = [UIApplication sharedApplication].keyWindow;

UIViewController *root = keyWindow.rootViewController;

if ([root presentedViewController]) {

    [rootdismissViewControllerAnimated:NO completion:nil];

}

keyWindow.rootViewController = LoginviewController

2、需要切换底部导航的时候、也必须要dismiss掉present出来的控制器、要不然页面没有反应、不会切换

1、重复第一步代码

2、UITabBarController *rootVC = (UITabBarController *)[UIApplication sharedApplication].keyWindow.rootViewController;

        if(rootVC && [rootVC isKindOfClass:[UITabBarController class]]) {

            if(rootVC.viewControllers.count>1) {

                rootVC.selectedIndex=1;

                UINavigationController *navigationController = (UINavigationController *)rootVC.selectedViewController;

                if([navigationController isKindOfClass:[UINavigationController class]]) {

                    // 先回到根                    

                    [navigationController popToRootViewControllerAnimated:NO];

                    [navigationController pushViewController:MessageVC animated:YES];