预加载tableView单元格并防止重新加载

Question

I already found entries with that topic on this page and also a website that provides a tutorial for that problem. But nothing worked very well.

The tutorial sad I should double the height of my tableView so cells loaded earlier, but with a higher tableView I never reached the last cells.

My problem is, I use a tableView to display my apps mainpage. This mainPage shows every time a topic and if its necessary for that topic it shows for example a cell with a map, one with pictures and sometimes not. Problem now, if I trying to scroll to my view its always lagging because it loads a map or this pictures. And scrolling back again because the loaded cells already deleted. I used a tableView because of the possibility to switch celltypes(mapCell, pictureCell, textCell) on and off.

I understand this feature, because of memory issues but in my case its not that much and it would be better if all my cells be preloaded and stay in memory until I change the topic.

Is there a swifty way to told my tableView to have this behavior?

Thanks a lot and nice greetings

Answer 1

I would suggest a different approach. Set up your table view controller to install placeholder images in your cells, trigger an async download that you cache to disk, and then update the cell with it's downloaded content if it's still visible when the download is finished.

There are various third party frameworks that do all this housekeeping for you.

Answer 2

Declare a cell array.

Follow these steps whenever change in your topic.

1. Clear you array

2. Create and configure all cells add to your array.

3. Return these cells to datasource methods using row index. Don't use tableview dequeue method here.