为什么我不能在viewWillAppear：animated同时调用reloadData和deselectRowAtIndexPath？ [英] Why can't I call reloadData AND deselectRowAtIndexPath in viewWillAppear:animated at the same time?

问题描述

我有一个UITableView与单元格，推动viewControllers到堆栈时选择。子viewControllers接受用户输入，然后弹出堆栈。

I have a UITableView with cells that push viewControllers onto the stack when selected. The child viewControllers take user input and then pops off the stack.

当子viewController弹出时，我想让父tableView更新所选单元格的值，然后取消选择该行。我可以使用reloadData更新单元格，我可以使用deselectRowAtIndexPath - 取消选择行，但我不能同时进行。

When the child viewController is popped, I want the parent tableView to update the value of the selected cell AND then deselect the row. I can update the cell using reloadData, and I can deselect the row using deselectRowAtIndexPath - but I can't do both at the same time.

我明白为什么这是 - reloadData隐式取消选择单元格，并且deselectRowAtIndexPath显式地取消选择它，但我发现很奇怪，我找不到任何人想要实现相同重新载入/取消选择行为。

I understand why this is - reloadData deselects the cell implicitly, and deselectRowAtIndexPath deselects it explicitly, but I find it curious that I can't find anyone wanting to achieve the same reload/deselect behavior. What am I missing here?

所有的代码都在viewWillAppear：animated - 如果我把deselectRowAtIndexPath放在viewWillAppear和reloadData in viewDidAppear，我可以关闭，但这不是什么

All code is in viewWillAppear:animated - I can get close if I put deselectRowAtIndexPath in viewWillAppear and reloadData in viewDidAppear, but this isn't what I want.

推荐答案

重新载入储存格时，系统会自动取消选取。这是因为你不在中将单元格的属性设置为 YES tableView：cellForRowAtIndexPath： 。所以你将不得不处理这个不同。要么识别 indexPath 的单元需要选择并适当地设置其 selected < $ 在中的属性到 YES 或者在重新加载数据后选择它。在这种情况下，您可以执行以下方法 -

When you reload a cell, it automatically gets deselected. That's because you don't set a cell's selected property to YES in tableView:cellForRowAtIndexPath:. So you will have to deal with this differently. Either identify that the cell at indexPath needs to be selected and appropriately set its selected property to YES in tableView:cellForRowAtIndexPath: or select it after you reload the data. In such case, you can execute the following methods –

[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                      withRowAnimation:UITableViewRowAnimationNone];

[self.tableView selectRowAtIndexPath:indexPath 
                            animated:NO
                      scrollPosition:UITableViewScrollPositionNone];

[self.tableView deselectRowAtIndexPath:indexPath animated:YES];

步骤的顺序是： -

The order of steps are :-

1. 重新载入没有任何动画的行。


2. 选择没有动画的行。 / li>
   

1. Reload the row without any animation.
2. Select the row without animation.
3. Deselect the row with animation.

这种方式我想你可以得到你想要的效果。

This way I think you can get the effect you want.

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