从NSInvocation获取参数值 [英] Getting argument values from NSInvocation

问题描述

有人可以解释如何获取传递给不存在的方法使用时被拦截的方法：

Could someone please explain how to go about getting the values passed to a non-existant method that is being intercepted when using:

+ (void)forwardInvocation:(NSInvocation *)anInvocation;

+ (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector;

给出如下消息：

[SomeClass doSomething:@"theThing" withSomething:@"aParam"];

我可以得到方法签名没有问题，但我非常困惑的如何获取值被传入与它。

I can get the method signature without a problem but I am terribly confused about how to get the values that were passed in with it.

当我应该使用这些方法或者只是缺少某些东西时，我是否完全禁用？

Am I totally off base in when I should use these methods or just missing something?

推荐答案

- [NSInvocation getArgument：atIndex：]

所以在你的case，你会使用它像：

So in your case, you would use it like:

__unsafe_retained NSString * firstArgument = nil;
__unsafe_retained NSString * secondArgument = nil;
[theInvocation getArgument:&firstArgument atIndex:2];
[theInvocation getArgument:&secondArgument atIndex:3];
NSLog(@"Arguments: %@ and %@", firstArgument, secondArgument);

请记住， self 和 _cmd 是参数0和1。

Remember that self and _cmd are arguments 0 and 1.

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