App开发 对生命周期的处理

//获取到当前所在的视图

- (UIViewController *)presentingVC:(UIApplication *)application{

UIWindow * window = application.keyWindow;

if (window.windowLevel != UIWindowLevelNormal){

NSArray *windows = [[UIApplication sharedApplication] windows];

for(UIWindow * tmpWin in windows){

if (tmpWin.windowLevel == UIWindowLevelNormal){

window = tmpWin;

break;

}

}

}

UIViewController *result = window.rootViewController;

while (result.presentedViewController) {

result = result.presentedViewController;

}

if ([result isKindOfClass:[MYTabBarViewController class]]) {

result = [(MYTabBarViewController *)result selectedViewController];

}

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

result = [(UINavigationController *)result topViewController];

}

return result;

}

#p --当应用程序退出后台进行的操作

- (void)applicationDidEnterBackground:(UIApplication *)application {

//进入后台执行的操作

UIViewController *viewC = [self presentingVC:application];

NSLog(@"viewC==%@",[viewC class]);

if ([viewC class]== [LoginViewController class]) {

[[NSUserDefaults standardUserDefaults] setObject:@"1" forKey:@"root"];

}else{

[[NSUserDefaults standardUserDefaults] setObject:@"0" forKey:@"root"];

//[self goBackForViewController];

}

}

#p --应用程序进入后台再进入前台进行的操作

- (void)applicationWillEnterForeground:(UIApplication *)application {

//进入前台执行的操作---原生页面

if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"root"] isEqualToString:@"0"]) {

//进入原生页面的不作处理

[self goBackForViewController];

}

//如果停留在H5页面，重新加载，防止session过期问题

else{

[self showViewControllers];

}

}

Documents:在iOS应用开发中使用应用周期进行相关的操作，可以很好处理应用生命周期之间的交互问题