how can you find out if an NSObject has a certain property?

问题

Let's say in Apple API version 1.0, there is a class NSFoo with a property 'color'. API 1.1 adds property 'size'.

I want to know whether I can use the getter: myFoo.size

[myFoo respondsToSelector:@selector(getSize)] doesn't work as expected.

What's the correct way to find out if an object has a property? Thanks!

回答1:

You're close. Your selector should be exactly the message you want to send to the object:

if ( [myFoo respondsToSelector:@selector(size)] ) {
    int size = [myFoo size]; // or myFoo.size in dot-notation.
    // ...
}

should work.

来源：https://stackoverflow.com/questions/3059029/how-can-you-find-out-if-an-nsobject-has-a-certain-property