如何在加载数据之前停止加载UITableView？ [英] How to stop UITableView from loading until data has been fetched?

问题描述

我理解 UITableView 将调用 - （UITableViewCell *）tableView：（UITableView *）tableView cellForRowAtIndexPath：（NSIndexPath *）indexPath 获取表视图的每个单元格的方法。假设我的数据源是通过互联网获取的，我必须考虑延迟。 停止调用此方法的最佳方法是什么？它应该阻止应用程序中的布尔标志吗？我应该从我的应用程序中再次调用 cellForRowAtIndexPath 吗？

I understand that UITableView will call -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath method to get each of the cells for the table view. Say I have my data source is fetched over the internet and I have to account for latency. What will be the best way of "stopping" this method from being called? Should it block on a boolean flag in the application? Should I just call cellForRowAtIndexPath again from within my application?

我不确定函数何时被调用，即 UITableView 刷新自身的频率。任何解释都会有所帮助！谢谢！

I am uncertain as to when the function gets called, ie, how often the UITableView "refreshes" itself. Any explanations will be helpful! Thanks!

推荐答案

如果您没有数据，或者您没有其他单元格的数据，那么<$只要您没有告诉UTableView您有rowCounts或new rowCounts，就不会调用c $ c> cellForRowAtIndex：。该值设置在 numberOfRowsInSection：。

If you don't have data, or you don't have the data for additional cells, then cellForRowAtIndex: will not be called as long as you don't tell the UTableView that you have rowCounts or new rowCounts. That value is being set in numberOfRowsInSection:.

换句话说，不报告 numberOfRowsInSection：，直到你实际拥有该数据为止，然后 cellForRowAtIndexPath：将不会过早被调用。

In other words, don't report any new cells in numberOfRowsInSection:, until you actually have that data in hand, and then cellForRowAtIndexPath: won't be called prematurely.

当你获得额外的行数据时，然后调用 reloadData 来让UITableView询问行数和然后调用 cellForRowAtIndex：。

When you do get the additional row data, then call reloadData to get the UITableView to ask for the number of rows and then call cellForRowAtIndex:.

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