[iOS]：检测视图控制器何时从另一个外部应用程序返回后出现

-(void) goToSetTings{
       [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSetTingsURLString]];
    }

- (void)applicationWillEnterForeground:(UIApplication *)application

设置视图控制器以侦听UIApplicationDidBecomeActiveNotification通知.

[[NsnotificationCenter defaultCenter] addObserver:self SELEctor:@SELEctor(becomeActive:) name:UIApplicationDidBecomeActiveNotification object:nil];

然后添加becomeActive：方法：

- (void)becomeActive:(Nsnotification *)notification {
    // App is active again - do something useful
}

并确保在适当的时候删除观察者.

[[NsnotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidBecomeActiveNotification object:nil];

当然,由于很多原因,您的应用可能会再次变为活动状态,而不仅仅是从“设置”应用返回.