iOS UITableViewAutomaticDimension RowHeight性能不佳/跳跃 [英] iOS UITableViewAutomaticDimension RowHeight Poor Performance / Jumping

问题描述

我正在iOS 8上构建一个基本的表格视图。我观看了WWDC '14关于自动调整单元格主题的视频，并试图重现这个概念，但是我遇到了一些问题。在viewDidLoad上：我正在打电话：

I'm building a basic table view on iOS 8. I watched the WWDC '14 video on the topic of autosizing cells and am trying to reproduce the concept, but am having some issues. On viewDidLoad: I am calling:

//estimate for my cells though they may vary

self.tableView.estimatedRowHeight = 300.0;

self.tableView.rowHeight = UITableViewAutomaticDimension;

当我的视图和表格加载时，性能还可以。当我单击一个单元格时，程序会将我带到详细视图。当我点击该视图上的后退按钮并返回到表格视图时，那就是事情开始变得怪异的时候。然后，当我滚动时，单元格开始跳跃。通过跳跃我的意思是他们不能顺利滚动 - 他们倾向于从一个地方跳跃或跳跃到下一个地方。

When my view and table load up, performance is ok. When I click on a cell, the program takes me to a detail view. When I hit the back button on that view and return to the table view, that's when things start acting weird. The cells then start 'jumping' while I am scrolling. By jumping I mean that they don't scroll smoothly - they tend to jerk or jump from one place to the next.

我应该补充一点，内存不是问题，因为单元格正在被重用，后台几乎没有数据。我的单元格（在故事板文件中）的约束也是蓝色的，我在调试器中看不到自动布局约束异常。

I should add that memory is not a concern since the cells are being reused and there is little data in the background. The constraints on my cells (in storyboard file) are also blue and I am seeing no autolayout constraint exceptions in the debugger.

有没有其他人看到过这种行为<强> UITableViewAutomaticDimension ？它只是一个苹果虫还是还有更多呢？谢谢。

Has anyone else seen this kind of behavior with UITableViewAutomaticDimension? Is it just an Apple bug or is there more to it? Thanks.

推荐答案

我发现使用行的奇怪问题self.tableView.rowHeight = UITableViewAutomaticDimension;

然而，当我用委托方法替换它时，一切都变得更好了。在你的情况下将是：

But then, everything came a lot better when I replaced it with the delegates method. In your case would be :

- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return UITableViewAutomaticDimension;
}

- (CGFloat) tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return 300.0f;
}

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