确保在主线程上调用reloadData。如果你从某种异步方法(例如:某种网络请求)调用该方法，表视图可能会或可能不会正确响应(在某些情况下，应用程序甚至会崩溃)。

使用主线程代码块来执行reloadData调用，如果调用是在其他一些方法块中进行的(你不确定):

[[NSOperationQueue mainQueue] addOperationWithBlock:^{
    [tableView reloadData];
}];

即使另一个答案已经被接受，我将为观察这个问题的人补充一个可能的问题和解决方案:

If you have automatic reference counting (ARC) turned on, you may find that even after assigning your controller as a delegate of the view, the view's messages to the controller are not being received because ARC is deleting the controller. Apparently the UITableView's delegate pointer does not count as a reference for the ARC, so if that is the only reference to it, the controller will be dealloc'd. You can verify whether or not this is happening by implementing the dealloc method on the controller and setting a breakpoint or NSLog call there.

解决方案是在其他地方使用强引用跟踪控制器，直到确定不再需要它为止。

我的问题不在上面。太差劲了。但我想我应该把它列在这里，也许它能帮助到别人。

I have a tableViewController that is my "base" controller and then I create subclasses of this controller. I was writing all my code in the tableView:didSelectRowAtIndexPath routine in the "base" class. Completely forgetting that by default this routine had also been created (albeit with no code that did anything) in all of my subclasses as well. So when I ran my app, it ran the subclass version of the code, did nothing, and made me sad. So of course, once I removed the routine from the subclasses, it used mt "base" class routine and I'm in business.

我知道。别笑。但也许这能帮别人省下我浪费的一小时…

听起来好像这个类不是表格视图的UITableViewDelegate，尽管UITableViewController应该自动设置。

你是否有机会将委托重置为其他类?

我刚遇到这个问题，但它并没有马上发生;在选择了几个单元格之后，它们将停止调用didSelectItemAtIndexPath。我意识到问题是集合视图将allowmultipleselection设置为TRUE。因为单元格从未被取消选择，这阻止了未来调用didSelectItemAtIndexPath。

如果您有一个自定义单元格，请记住在Xib中(或通过代码)为单元格设置UserInteractionEnabled。