查找键值编码路径

Question

Key-value coding paths are useful in UIKit. They often allow you to configure elements that aren't specified in the public API of a view, or in the Interface Builder inspector for that view.

For instance, you can configure the text color of UIDatePicker using textColor key path, but there doesn't seem to be a property or method exposing that configuration -- the only way to do it is through key-value coding.

Given that -- how can one as an iOS developer find key-value coding paths for elements? I found this particular example in a StackOverflow response, but how did they find it? I'd love to be able to inspect these classes and find their key-value coding paths myself, or at least have a good crowdsourced reference to all the KVC key paths that might be useful when I'm trying to customize a view.

Answer 1

You can use class-dump to view all properties on an Objective-C class, including private properties (properties with the _ underscore prefix)

But also yes as @rmaddy said, most of the time you won't want to modify private properties-- but it should be pretty safe if you are just reading and not writing. For example, NSUndoManager has a private property, _undoStack , which is super useful to read so you can see what is currently in your undo stack