如何返回到前一个视图控制器？

Question

当用户从UIAlertController弹出窗口中单击“确定”按钮时，它将返回到先前的视图控制器。我坚持如何。下面是我的代码。

if (jsonData == nil){ 
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Error!" message:@"This Git repository is empty" preferredStyle:UIAlertControllerStyleAlert]; 

    UIAlertAction* ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]; 
    [alertController addAction:ok]; 

    [self presentViewController:alertController animated:YES completion:nil]; 

     } 

Answer 1

试试这个 -

if (jsonData == nil){ 
     UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Error!" message:@"This Git repository is empty" preferredStyle:UIAlertControllerStyleAlert]; 

     UIAlertAction* ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action){ 
      // Ok action example 
      [self.navigationController popViewControllerAnimated:YES]; 
     }]; 
     [alertController addAction:ok]; 

     [self presentViewController:alertController animated:YES completion:nil]; 
    }