UIViewController 代码添加导航栏

如果创建的UIViewController是不带导航的，可以通过在viewDidLoad方法中调用如下实现来添加导航栏：

- (void)setNavigationbar

{

    

    CGRect screenRect = [[UIScreen mainScreen] bounds];

    UINavigationBar *navigationBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, screenRect.size.width, 44)];

    navigationBar.tintColor = [UIColor redColor];

    //创建UINavigationItem

    UINavigationItem * navigationBarTitle = [[UINavigationItem alloc] initWithTitle:@"创建UINavigationBar"];

    [navigationBar pushNavigationItem: navigationBarTitle animated:YES];

    [self.view addSubview: navigationBar];

    //创建UIBarButton 可根据需要选择适合自己的样式

    UIBarButtonItem *item = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemReply target:self action:@selector(navigationBackButton:)];

    //设置barbutton

    navigationBarTitle.leftBarButtonItem = item;

    [navigationBar setItems:[NSArray arrayWithObject: navigationBarTitle]];

}