iOS 从appDelegate跳转其他子控制器

1. 获取当前视图控制器

• (UIViewController *)currentViewController {
  UIViewController *result = nil;
  UIWindow *window = [[UIApplication sharedApplication] keyWindow];
  //app默认windowLevel是UIWindowLevelNormal，如果不是，找到UIWindowLevelNormal的
  if (window.windowLevel != UIWindowLevelNormal) {
  NSArray *windows = [[UIApplication sharedApplication] windows];
  for(UIWindow *tmpWin in windows) {
  if (tmpWin.windowLevel == UIWindowLevelNormal) {
  window = tmpWin;
  break;
  }
  }
  }
  id nextResponder = nil;
  UIViewController *appRootVC=window.rootViewController;
  if (appRootVC.presentedViewController) {
  nextResponder = appRootVC.presentedViewController;
  } else {
  UIView *frontView = [[window subviews] objectAtIndex:0];
  nextResponder = [frontView nextResponder];
  }

  if ([nextResponder isKindOfClass:[UITabBarController class]]){
  UITabBarController *tabbar = (UITabBarController *)nextResponder;
  UINavigationController *nav = (UINavigationController *)tabbar.viewControllers[tabbar.selectedIndex];
  result = nav.childViewControllers.lastObject;

  } else if ([nextResponder isKindOfClass:[UINavigationController class]]){
  UIViewController *nav = (UIViewController *)nextResponder;
  result = nav.childViewControllers.lastObject;
  } else {
  result = nextResponder;
  }
  return result;
  }

2.实现跳转到指定视图控制器
UIViewController * currentVC = [self currentViewController];
HYTAdditionalInsuranceViewController *addInsureVC = [[HYTAdditionalInsuranceViewController alloc] init];
[currentVC.navigationController pushViewController:addInsureVC animated:YES];

或者跳转到指定tabbarController
TabBarController *tabbar = [[TabBarController alloc] init];
tabbar.selectedIndex = 0;
self.window.rootViewController = tabbar;