如何比较两个NSIndexPaths？ [英] How to compare two NSIndexPaths?

问题描述

我正在寻找一种方法来测试索引路径是否相等，并且相等我的意思是在每个级别上相等？我试过比较：但它似乎不起作用，与 NSOrderedSame 相比，我总是如此，即使索引是绝对不一样。

I'm looking for a way to test if to index paths are equal, and by equal I mean equal on every level? I tried compare: but it seems not to work, I always get true when compared with NSOrderedSame even if the indexes are definitely not the same.

推荐答案

几乎所有的Objective-C对象都可以使用进行比较isEqual：方法。所以，为了测试相等性，你只需要 [itemCategoryIndexPath isEqual：indexPath] ，你就可以了。现在，这是因为 NSObject 实现 isEqual：，所以所有对象都自动拥有该方法，但是如果某个类没有'覆盖它， isEqual：只会比较对象指针。

Almost all Objective-C objects can be compared using the isEqual: method. So, to test equality, you just need [itemCategoryIndexPath isEqual:indexPath], and you're good to go. Now, this works because NSObject implements isEqual:, so all objects automatically have that method, but if a certain class doesn't override it, isEqual: will just compare object pointers.

在 NSIndexPath ，由于 isEqual：方法已被覆盖，因此您可以按预期方式比较对象。但是，如果我要编写一个新类 MyObject 而不重写该方法， [instanceOfMyObject isEqual：anotherInstanceOfMyObject] 将实际上与 instanceOfMyObject == anotherInstanceOfMyObject 相同。

In the case of NSIndexPath, since the isEqual: method has been overridden, you can compare the objects as you were to expect. But if I were to write a new class, MyObject and not override the method, [instanceOfMyObject isEqual:anotherInstanceOfMyObject] would effectively be the same as instanceOfMyObject == anotherInstanceOfMyObject.

你可以在 NSObject中阅读更多内容协议参考。

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