点击这里查看问答:https://developer.apple.com/library/content/qa/qa1561/_index.html

Q: How do I programmatically quit my iOS application? There is no API provided for gracefully terminating an iOS application. In iOS, the user presses the Home button to close applications. Should your application have conditions in which it cannot provide its intended function, the recommended approach is to display an alert for the user that indicates the nature of the problem and possible actions the user could take — turning on WiFi, enabling Location Services, etc. Allow the user to terminate the application at their own discretion. WARNING: Do not call the exit function. Applications calling exit will appear to the user to have crashed, rather than performing a graceful termination and animating back to the Home screen. Additionally, data may not be saved, because -applicationWillTerminate: and similar UIApplicationDelegate methods will not be invoked if you call exit. If during development or testing it is necessary to terminate your application, the abort function, or assert macro is recommended

- (IBAction)logOutButton:(id)sender
{
   //show confirmation message to user
   CustomAlert* alert = [[CustomAlert alloc] initWithTitle:@"Confirmation" message:@"Do you want  to exit?" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"OK", nil];
   alert.style = AlertStyleWhite;
   [alert setFontName:@"Helvetica" fontColor:[UIColor blackColor] fontShadowColor:[UIColor clearColor]];
   [alert show];
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{

   if (buttonIndex != 0)  // 0 == the cancel button
   {
      //home button press programmatically
      UIApplication *app = [UIApplication sharedApplication];
      [app performSelector:@selector(suspend)];
      //wait 2 seconds while app is going background
      [NSThread sleepForTimeInterval:2.0];
      //exit app when app is in background
      NSLog(@"exit(0)");
      exit(0);
  }
}

嗯，如果你的应用需要网络连接，你可能“不得不”退出应用程序。你可以显示一个警告，然后做这样的事情:

if ([[UIApplication sharedApplication] respondsToSelector:@selector(terminate)]) {
    [[UIApplication sharedApplication] performSelector:@selector(terminate)];
} else {
    kill(getpid(), SIGINT); 
}

你不应该直接调用函数exit(0)，因为它会立即退出应用程序，看起来就像你的应用程序崩溃了。所以最好是给用户显示一个确认提醒，让他们自己去做。

斯威夫特4.2

func askForQuit(_ completion:@escaping (_ canQuit: Bool) -> Void) {
    let alert = UIAlertController(title: "Confirmation!", message: "Do you want to quit the application", preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: "Yes", style: UIAlertAction.Style.default, handler: { (action) in
        alert.dismiss(animated: true, completion: nil)
        completion(true)
    }))
    alert.addAction(UIAlertAction(title: "No", style: UIAlertAction.Style.cancel, handler: { (action) in
        alert.dismiss(animated: true, completion: nil)
        completion(false)
    }))
    self.present(alert, animated: true, completion: nil)
}

/// Will quit the application with animation
func quit() {
    UIApplication.shared.perform(#selector(NSXPCConnection.suspend))
    /// Sleep for a while to let the app goes in background
    sleep(2)
    exit(0)
}

用法:

self.askForQuit { (canQuit) in
     if canQuit {
         self.quit()
     }
}

去你的信息。plist并检查关键“应用程序不运行在后台”。这一次，当用户单击home按钮时，应用程序将完全退出。

用户应该决定应用程序何时退出。 我不认为当应用退出时这是一种良好的用户交互。因此，它没有很好的API，只有home按钮有一个。

如果有错误:更好地实现它或通知用户。 如果必须重新启动:执行它更好的通知用户。

这听起来很愚蠢，但在不让用户决定的情况下退出应用程序，并且不通知他，这是一种糟糕的做法。苹果表示，由于有一个home键用于用户交互，所以同一个功能(退出应用程序)不应该有两个东西。