判斷並打開系統設置

參考了這位博主的文章：

http://www.jianshu.com/p/19602f48309b

//在應用活躍的時候判斷系統設置中的通知是否打開

- (void)applicationDidBecomeActive:(UIApplication *)application {

    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.

          if (SYSTEM_VERSION < 8.0) {

            if ([[UIApplication sharedApplication] enabledRemoteNotificationTypes] == UIRemoteNotificationTypeNone && !titleView) {

                titleView = [[SFGlobalAlertView alloc] initWithMessage:@"檢測到系統禁止了消息推送，這樣會致使您沒法及時收到消息" delegate:self type:GlobalAlertViewTypeDefault];

                [titleView setLeftButtonTitle:@"當即設置" imageWithNormalImageName:nil

                           highlightImageName:nil];

                [titleView setRightButtonTitle:@"再也不提醒" imageWithNormalImageName:nil highlightImageName:nil];

                titleView.tag = SFGlobalViewTagForNotiSetting;

                [titleView show];

                

            }

            

        }else

        {

            UIUserNotificationType types = [[UIApplication sharedApplication] currentUserNotificationSettings].types;

           

            if (types == UIUserNotificationTypeNone && !titleView) {

                 titleView = [[SFGlobalAlertView alloc] initWithMessage:@"檢測到系統禁止了消息推送，這樣會致使您沒法及時收到消息" delegate:self type:GlobalAlertViewTypeDefault];

                [titleView setLeftButtonTitle:@"當即設置" imageWithNormalImageName:nil

                           highlightImageName:nil];

                [titleView setRightButtonTitle:@"再也不提醒" imageWithNormalImageName:nil highlightImageName:nil];

                [titleView show];

                titleView.tag = SFGlobalViewTagForNotiSetting;

            }

        }

  }

  

//若是沒有打開，則進入設置

    if(SYSTEM_VERSION < 8.0)

           {

               [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=INTERNET_TETHERING"]];

           }else

         {

                 NSURL *url =[NSURL URLWithString:UIApplicationOpenSettingsURLString];

             if([[UIApplication sharedApplication] canOpenURL:url]) {

                 

                 [[UIApplication sharedApplication] openURL:url];

                 

             }

         }