iphone - 如何以编程方式添加按钮以删除 WebView？

Question

我试图将 UIBarButtonItem 添加到我的 UINavigation 栏，但我无法让它显示:

  - (void)viewDidLoad {
      [super viewDidLoad];

      self.webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 50, self.view.frame.size.width,self.view.frame.size.height)];
      [self.view addSubview:self.webView];

      UIBarButtonItem *backButton = [[UIBarButtonItem alloc]
                                    initWithTitle:NSLocalizedString(@"Back", @"")
                                    style:UIBarButtonItemStyleDone
                                    target:self
                                     action:@selector(remove:)];

      [self.navigationItem setLeftBarButtonItem: backButton];

       UINavigationBar *myBar = [[UINavigationBar alloc]initWithFrame:CGRectMake(0, 0, 320, 50)];


      [self.view addSubview:myBar];

      self.webView.delegate = self;

      NSURLRequest *request = [NSURLRequest requestWithURL:self.url];
      [self.webView loadRequest:request];

  }

  - (void)remove:(id)sender
  {
      [self removeFromParentViewController];
      [self.webView stopLoading];
      self.webView.delegate = nil;
  }

我不明白为什么没有按钮。任何帮助将不胜感激!

谢谢。

Answer 1

在将 UIBarButtonItem 添加到 UINavigationBar 之前，首先更改您的 UIWebView 框架，

self.webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 50, self.view.frame.size.width,self.view.frame.size.height - 50 )];

此处将 (-50) 添加到 UIWebView 的高度。

现在，我只是编写如何将 UIBarButtonItem 添加到 UINavigationBar 的代码:

   UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 320, 50)];
    [self.view addSubview:navBar];
    UIBarButtonItem *Button = [[UIBarButtonItem alloc]
                               initWithTitle:@"MyButton"
                               style:UIBarButtonItemStyleBordered
                               target:self
                               action:@selector(buttonAction)];

    UINavigationItem *item = [[UINavigationItem alloc] initWithTitle:@"This is My Title "];
    item.rightBarButtonItem = Button;
    item.hidesBackButton = YES;
    [navBar pushNavigationItem:item animated:NO];

这是方法名称是 buttonAction，当您点击 UIBarButtonItem 时执行/调用。

-(void)buttonAction
{
  //stuff of code;
}