IOS captures unknown method calls, avoids throwing exceptions

IOS captures unknown method calls, avoids throwing exceptions

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The NSObject object is the root class in Objecitve-c, which has the following two methods that, when a method that calls NSObject and its subclasses does not exist, encapsulates the call as a nsinvocation * type, attempting to pass it to the Forwardinvocation: method, if the object that was called by the original method overloads the Forwardinvocation: method,forwardinvocation: The method is called.

Forwardingtargetforselector: The real use, from the official website of the description, or not fully understand its available scenes, but the latter method in the reflection processing when used, see " O-r Mapping for the JSON data source implemented by IOS ".

Forwardingtargetforselector:

Returns the object to which the unknown message should first be turned.
Returns the object to which unrecognized messages should first is directed.

-(ID) Forwardingtargetforselector: (SEL)AselectorForwardinvocation:

A subclass overload that is used to forward messages to other objects.
Overridden by subclasses to forward messages to other objects.

-(void) Forwardinvocation: (Nsinvocation *)aninvocation

-(void) Forwardinvocation: (nsinvocation *) invocation {        SEL orignalselector = [invocation selector];        if ([friend Respondstoselector:orignalselector]) {                [invocation invokewithtarget:friend];    }        else {                [super forwardinvocation:invocation];}    }