Pop方式

    ElseStationVController *flagVC = nil;
    
    for (id object in self.navigationController.viewControllers) {
        //判断元素是否是第二个控制器创建的
        if ([object isKindOfClass:[ElseStationVController class]]) {
            flagVC = object;
            
            break;
        }
    }
    
    if (flagVC != nil) {
 
           [self.navigationController popToViewController:flagVC animated:YES];
    }