定義

#import <Foundation/Foundation.h>
@class EOCNetworkFetcher;

@protocol EOCNetworkFetcherDelegate<NSObject>
- (void)networkFetcher:(EOCNetworkFetcher *)nerworkFetcher
     didFinishWithData:(NSData *)data;
@end

@interface EOCNetworkFetcher : NSObject
@property(nonatomic,weak) id <EOCNetworkFetcherDelegate> delegate;
- (id)initWithURL:(NSURL*)URL;
- (void)start;
@end

其他類可以這樣使用

//設(shè)置代理部分
- (void)fetchFooData{
    NSURL *url = [[NSURL alloc] initWithString:@""];
    _fooFetcher = [[EOCNetworkFetcher alloc] initWithURL:url];
    _fooFetcher.delegate = self;
    [_fooFetcher start];
}

- (void)fetchBarData{
    NSURL *url = [[NSURL alloc] initWithString:@""];
    _barFetcher = [[EOCNetworkFetcher alloc] initWithURL:url];
    _barFetcher.delegate = self;
    [_barFetcher start];
}

//實(shí)現(xiàn)代理部分
- (void)networkFetcher:(EOCNetworkFetcher *)nerworkFetcher
     didFinishWithData:(NSData *)data{
    if(networkFetcher == _fooFetcher){
        _fetchedFooData = data;
        _fooFetcher = nil;
    }else{
        _fetchedBarData = data;
        _barFetcher = nil;
    }
}