![Message
ÿ?һA Objective-C e?涼
v, е Method \?{?, ҕ
[reciver message];](https://image.slidesharecdn.com/objective-cruntime2-150807071143-lva1-app6892/85/Objective-c-runtime-2-6-320.jpg)
![Message
reciver Ҫ\?@ Method Object
message tҪ\?е Method name
ex: [normalObject invoke];
[NormalObject randomIntegerValue];](https://image.slidesharecdn.com/objective-cruntime2-150807071143-lva1-app6892/85/Objective-c-runtime-2-7-320.jpg)
![Message
compiler ֻ Method D
[normalObject invoke];
to
objc_msgSend(normalObject, @selector(invoke));](https://image.slidesharecdn.com/objective-cruntime2-150807071143-lva1-app6892/85/Objective-c-runtime-2-9-320.jpg)
![Message
[NormalObject randomIntegerValue];
to
objc_msgSend([NormalObject class],
@selector(randomIntegerValue));](https://image.slidesharecdn.com/objective-cruntime2-150807071143-lva1-app6892/85/Objective-c-runtime-2-10-320.jpg)
Objective c runtime 2
- 2. Review 2
- 3. Review ? ٵĻ?һ, ?һ message ?ߵ doesNotRecognizeSelector: ^ ȵęC.
- 4. Review 1. + (BOOL)resolveInstanceMethod:(SEL)name; 2. - (id)forwardingTargetForSelector:(SEL)aSelector; 3. - (NSMethodSignature*)methodSignatureForSelec tor:(SEL)aSelector; - (void)forwardInvocation:(NSInvocation *)anInvocation;
- 5. Message 5
- 6. Message ÿ?һA Objective-C e?涼 v, е Method \?{?, ҕ [reciver message];
- 7. Message reciver Ҫ\?@ Method Object message tҪ\?е Method name ex: [normalObject invoke]; [NormalObject randomIntegerValue];
- 8. Message Ȼ?, _Ҫ\?е reciver Ă Object, compiler K֪, l ?, Runtime ĕrŕQ.
- 9. Message compiler ֻ Method D [normalObject invoke]; to objc_msgSend(normalObject, @selector(invoke));
- 11. Message P objc_msgSend ʲN, ?Wվ @ӸV҂.
- 12. Message 1. It first finds the procedure (method implementation) that the selector refers to. Since the same method can be implemented differently by separate classes, the precise procedure that it finds depends on the class of the receiver.
- 13. Message 2. It then calls the procedure, passing it the receiving object (a pointer to its data), along with any arguments that were specified for the method.
- 14. Message 3. Finally, it passes on the return value of the procedure as its own return value.
- 15. Message
- 17. Message 1. z reciver Ƿ nil
- 18. Message 2. z@ method IMP Dzѽ class cache
- 20. Message
- 21. Q&A
- 22. Reference Objective-C Runtime Programming Guide A Look Under the Hood of objc_msgSend() Chapter 4 Assembly Language