ios - 当 NSUrlSendAssynchronousrequest 操作运行时，选项卡栏应用程序按钮被阻止

Question

我有一个选项卡栏应用程序，其中一个按钮将网页内容加载到 UIWebView。 我面临的问题是，当连接尝试获取数据时，选项卡栏按钮没有响应，直到页面加载完成或连接失败。 是否有更好的方法来执行此操作，以便用户可以在他/她改变主意时切换出该选项卡。 谢谢，这是代码:

- (void)loadThrillsSite
{
    [self.webView setDelegate:self];
    NSString *urlString = @"https://www.Thrills.in";
    NSURL *url = [NSURL URLWithString:urlString];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    NSOperationQueue *queue = [[NSOperationQueue alloc] init];

    [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
     {
         if ([data length] > 0 && error == nil) [self.webView loadRequest:request];
         else if (error != nil) {
             UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Connection Error!" message:@"Failed to connect to server\nPlease check your internet connection and try again" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
             [alert show];
         }
     }];
}

- (void)webViewDidFinishLoad:(UIWebView *)webView;
{
    [hudImageView removeFromSuperview];

    [self.spinner stopAnimating];

    [patternView removeFromSuperview];
}

Answer 1

UIWebView的loadRequest方法说明:

Connects to a given URL by initiating an asynchronous client request.

它已经进行了异步调用，因此您无需使用其他 block 。只需调用 [self.webView loadRequest:request]; 您可以在 - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error 方法上处理错误。

其他注意事项:您的网址现在无法正常工作，并且不要执行任何与 UI 相关的工作，例如在后台线程上显示警报 View 。希望对您有所帮助。

- (void)loadThrillsSite
{
    [self.webView setDelegate:self];
    NSString *urlString = @"https://www.Thrills.in";
    NSURL *url = [NSURL URLWithString:urlString];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    [self.webView loadRequest:request];
}

- (void)webViewDidFinishLoad:(UIWebView *)webView;
{
    [hudImageView removeFromSuperview];

    [self.spinner stopAnimating];

    [patternView removeFromSuperview];
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
    UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Connection Error!" message:@"Failed to connect to server\nPlease check your internet connection and try again" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alert show];
}