iphone - 调用connectionDidFinishLoading后更新 View Controller

Question

我正在尝试异步加载网页内容。我不确定调用 connectionDidFinishLoading 方法后如何更新 View Controller 中的标签/其他内容。在下面的示例中，我只是尝试更新标签以显示内容已加载。我该怎么做？谢谢!

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"Succeeded! Received %d bytes of data",[responseData
                                                   length]);
    NSString *txt = [[NSString alloc] initWithData:responseData encoding: 
    NSASCIIStringEncoding];

    label.text = @"DISPLAY THIS WHEN FINISHED";  
}

我被告知让我的viewController成为NSURLConnectionDelegate，然后从viewDidLoad运行fetchData方法，然后使用在connectionDidFinishLoading中获取数据时为我们获取的数据。有人知道从哪里开始吗？谢谢!

Answer 1

正如 Ramy 正确指出的那样，您必须在主线程上更新 UI，然后:

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
   NSLog(@"Succeeded! Received %d bytes of data",[responseData length]);
   NSString *txt = [[NSString alloc] initWithData:responseData 
                                         encoding: NSASCIIStringEncoding];

  NSString *text = @"DISPLAY THIS WHEN FINISHED";
  [label performSelectorOnMainThread:@selector(setText:) withObject:text waitUntilDone:NO]
}