不符合协议Swift父类-目标C协议

Question

I am trying to call my Protocol Class in Swift, but its giving me Error

"Type SwiftViewController does not conform to protocol ABCDelegate.

Could you please tell me what I am missing , as I find other posts , but nothing is explained properly , also let me know if you need more info.

@protocol ABCDelegate <NSObject>
@required
- (void) ABC:(NSString*)MessageResponseStr
@end
@interface ABC : NSObject

@property (nonatomic, assign) id<ABCDelegate> delegate;
@property(nonatomic,retain)NSString *ResponseStr;
-(void)Network:(int)NetworkState 

Answer 1

A protocol defines abstract behaviour.

Like interface in many other languages. ABCDelegate protocol simply states: Anything that will implement me, need to specify the following required methods, and can choose to implement the following optional methods.

In your case, your class need to implement the protocol required ABC method.

Answer 2

When you defined the protocol in ABC class, you declared the protocol method to be @required as in -

@protocol ABCDelegate <NSObject>
@required
- (void) ABC:(NSString*)MessageResponseStr
@end

Now in SwiftViewController or any class that implements the protocol, it has become mandatory to add the - (void) ABC:(NSString*)MessageResponseStr because of the @required keyword.

As soon as you implement the method, error will go away.

Hope this helped.