title: Cannot hide MBProgressHUD in iOS
body: <p>I tried this code to show <code>MBProgressHUD</code> but when I click on another tab and back to this tab, <code>MBProgressHUD</code> cannot hide. I tried this for 2 functions:</p>
  
  <p>For <code>updatearray()</code></p>
  
  <pre><code> MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
  hud.mode = MBProgressHUDModeIndeterminate;
  hud.labelText = @"Loading..";
  dispatch_queue_t dispatchQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
  dispatch_async(dispatchQueue, ^(void)
  {
  [self updatearray];
  dispatch_sync(dispatch_get_main_queue(), ^{ 
  [hud hide:YES];
  });
  }); 
  </code></pre>
  
  <p>for getVideolist()</p>
  
  <pre><code> MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
      hud.mode = MBProgressHUDModeIndeterminate;
      hud.labelText = @"Loading..";
      dispatch_queue_t dispatchQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
      dispatch_async(dispatchQueue, ^(void)
      {
      [self getVideolist];
      dispatch_sync(dispatch_get_main_queue(), ^{ 
      [hud hide:YES];
      });
      }); 
  </code></pre>
  
  <p>In first time, it runs ok. But after click on another tab and back, it cannot hide.</p>