添加的按钮不会显示在UINavigationController上

Question

我正在尝试动态创建一个viewcontroller并设置其视图和标题栏.事情似乎工作得很好.但是当我尝试设置导航栏的左按钮或右按钮时,它们就不会显示出来.我究竟做错了什么？

   UIWebView *tempWebView = [[UIWebView alloc] initWithFrame:self.view.bounds];
    [tempWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"someurl"]]];

    UIViewController* tempViewController = [[UIViewController alloc]init];
    tempViewController.view = tempWebView;

    UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:tempViewController];

    UIBarButtonItem* closeButton = [[UIBarButtonItem alloc] initWithTitle:@"Close" style:UIBarButtonItemStyleBordered target:self action:nil];
    navigationController.navigationItem.leftBarButtonItem = closeButton;


    [self presentViewController:navigationController animated:YES completion:nil];

Answer 1

更改

navigationController.navigationItem.leftBarButtonItem = closeButton;

至

tempViewController.navigationItem.leftBarButtonItem = closeButton;

该navigationItem外观由正由导航控制器呈现在观察处理,因此,如果您设置的UINavigationController,但不上rootViewController,当你把它的第一次它被覆盖.