为什么第二次不会调用DisplayCell

Question

I have a view controller with a table. When a cell is created and presented the first time, the following functions are called in the order (in addition to view controller functions):

....
func viewWillAppear(_ animated: Bool)

func cellForRow(at indexPath: IndexPath) -> UITableViewCell? 

optional func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)

func viewWillDisappear(_ animated: Bool)
.... 

When I exit the screen an, the following functions were called.

....
func viewWillAppear(_ animated: Bool)

func viewWillDisappear(_ animated: Bool)
.... 

But why willDisplaycell was not called between viewWillAppear and viewWillDisappear ?

The logs are:

viewWillAppear
cellForRowAtIndexPath: 0 
willDisplayCell: 0 
cellForRowAtIndexPath: 1 
willDisplayCell: 1 
cellForRowAtIndexPath: 2 
willDisplayCell: 2 
viewWillDisappear
viewWillAppear
viewWillDisappear

Instead of:

viewWillAppear
cellForRowAtIndexPath: 0 
willDisplayCell: 0 
cellForRowAtIndexPath: 1 
willDisplayCell: 1 
cellForRowAtIndexPath: 2 
willDisplayCell: 2 
viewWillDisappear
viewWillAppear
willDisplayCell: 0 
willDisplayCell: 1 
willDisplayCell: 2 
viewWillDisappear

Answer 1

What I did eventually is checking what cells are presented in viewDidAppear. Not sure it's the best answer, so don't hesitate to add better ones.

-(void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    [self logVisibleSections];
}

-(void)logVisibleSections
{
    for (NSIndexPath *indexPath in self.tableView.indexPathsForVisibleRows)
    {
        // Do what needs to be done with visible cells 
    }
}