Objective c 使用POST方法时，iphone MBProgreeHUD不工作

当我试图将一些图像或文本从应用程序发布到服务器时，这种情况是不起作用的。但没有张贴方法，它的工作是完美的。我使用下面的代码。请任何人帮助我。谢谢

HUD = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
HUD.dimBackground = YES;
HUD.delegate = self;

NSString *urlRequest =[NSString stringWithFormat:@"URL"];
NSString *pStrLegalURLString =[urlRequestn stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [[NSURL alloc] initWithString:pStrLegalURLString];
NSMutableURLRequest *request1 = [NSMutableURLRequest requestWithURL:url];
[request1 setHTTPMethod:@"POST"];

NSData *returnData1 = [ NSURLConnection sendSynchronousRequest: request1 returningResponse: nil error: nil ];
NSString *returnString1 = [[NSString alloc] initWithData:returnData1 encoding: NSUTF8StringEncoding];

试着这样做：

它可以工作，但我想您的问题是因为

sendSynchronousRequest

是一个阻塞调用，因此如果主线程挂起，您将不会在UI中看到任何更新。所以试着在后台打这样的电话

尝试我看到的两种方法之一：

方法1：（使用选择器在后台发送请求，并在主线程中进行UI更新） 方法2：使用Dispatch\u Async和Dispatch\u Sync

---

谢谢，现在工作很好。sendSynchronousRequest，这是一个阻止调用。

-(void)method1 {
HUD = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
HUD.dimBackground = YES;
HUD.delegate = self;

NSString *urlRequest =[NSString stringWithFormat:@"URL"];
NSString *pStrLegalURLString =[urlRequest stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [[NSURL alloc] initWithString:pStrLegalURLString];
NSMutableURLRequest *request1 = [NSMutableURLRequest requestWithURL:url];
[request1 setHTTPMethod:@"POST"];

// send request in background.
[self performSelectorInBackground:@selector(method2) withObject:nil];
}

-(void)method2 {
NSData *returnData1 = [ NSURLConnection sendSynchronousRequest: request1 returningResponse: nil error: nil ];
NSString *returnString1 = [[NSString alloc] initWithData:returnData1 encoding: NSUTF8StringEncoding];

[self performSelectorOnMainThread:@selector(method3) withObject:nil waitUntilDone:NO];
}

-(void)method3
{
   // update ui in main thread.
   [MBProgressHUD hideAllHUDsForView:self.view animated:YES];
}

dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^(void){

    // Do background work here

    dispatch_sync(dispatch_get_main_queue(), ^(void){

        // Update UI here
    });
});