向右滑动返回上一级界面

    /*
    向右滑动返回上一级界面,将代码写在第一级界面，那么后面的界面也都可以实现此功能，
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0) {
        
        self.navigationController.interactivePopGestureRecognizer.enabled = YES;
        
        self.navigationController.interactivePopGestureRecognizer.delegate = self;
    
    }
    if ([[[UIDevice currentDevice] systemVersion] floatValue]
        >= 7.0) {
      
        self.navigationController.interactivePopGestureRecognizer.delegate = self;
        
    }
     */