How can I differentiate the same method name of tw

问题:

I have two protocols

@protocol P1

-(void) printP1;

-(void) printCommon;

@end


@protocol P2

-(void) printP2;

-(void) printCommon;
@end

Now, I am implementing these two protocols in one class

@interface TestProtocolImplementation : NSObject <P1,P2>
{

}

@end

How can i write method implementation for "printCommon". When i try to do implementation i have compile time error.

Is there any possibility to write method implementation for "printCommon".

回答1:

The common solution is to separate the common protocol and make the derived protocols implement the common protocol, like so:

@protocol PrintCommon

-(void) printCommon;

@end

@protocol P1 < PrintCommon > // << a protocol which declares adoption to a protocol

-(void) printP1;

// -(void) printCommon; << available via PrintCommon

@end


@protocol P2 < PrintCommon >

-(void) printP2;

@end

Now types which adopt P1 and P2 must also adopt PrintCommon's methods in order to fulfill adoption, and you may safely pass an NSObject<P1>* through NSObject<PrintCommon>* parameters.

回答2:

for me the following code did worked:

@protocol P1    

- (void) method1;

@end

@protocol P2

- (void) method1;
- (void) method2;

@end

@interface C1 : NSObject<P1, P2>

@end

@implementation C1

- (void) method1
{
    NSLog(@"method1");
}

- (void) method2
{
    NSLog(@"method2");
}

@end

Compiler user: Apple LLVM 3.0 But if you're designing a solution like this, try to avoid such situations.