ios - 显示消息会导致崩溃吗？

Question

我有这个代码:

[NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
 {         
     NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;

     if ( error != nil )
     {
         // Display a message to the screen.
         UIAlertView *message = [[UIAlertView alloc] initWithTitle:@"There was a server error getting your business plan. We use a remote server to backup your work." 
                    message:@"Please make sure your phone is connected to the Internet. If the problem persists, please let us know about this." 
                delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];

         [message show];

但它会在 NSUrlConnection 从服务器返回时执行。它在极少数情况下会造成崩溃。是否可以？这似乎是一段无害的代码。

谢谢!

Answer 1

NSURLConnection 是否在某个奇怪的线程上返回结果？我不知道，但我怀疑 UIAlertView 只能在 UI 线程上工作，因为它是从 UI 开始的。

 (dispatch_async(dispatch_get_main_queue(), ^{ 
    UIAlertView *message = [[UIAlertView alloc] initWithTitle:@"There was a server error getting your business plan. We use a remote server to backup your work." 
                message:@"Please make sure your phone is connected to the Internet. If the problem persists, please let us know about this." 
            delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];

     [message show];
 });)

抱歉，还没有编译这个，可能某处有错别字。