在AFNetworking上怎么用AFJSONRequestOperation来请求数据

许多微博上都这样请求数据

1 NSURL *url = [NSURL URLWithString:@"http://api.twitter.com/1/statuses/public_timeline.json"];
2 NSURLRequest *request = [NSURLRequest requestWithURL:url];
3 AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) 
  {
4 NSLog(@"Public Timeline: %@", JSON);
  } failure:nil];
5 [operation start];

为什么AFJSONRequestOperation不能用

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这样从manager来拿operation的实例是木有问题的，你可以command＋鼠标，点进去看看manager对operation做了拿些配置。他最后也是把operation添加到operationQueue里面来开始任务的，而不是直接用的start

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.responseSerializer = [AFJSONResponseSerializer serializer];    manager.requestSerializer = [AFJSONRequestSerializer serializer];
AFHTTPRequestOperation *operation = [manager HTTPRequestOperationWithRequest:request success:^(AFHTTPRequestOperation *operation, id responseObject) {
            NSInteger statusCode = operation.response.statusCode;
            //...
        } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
            NSInteger statusCode = operation.response.statusCode;
            //...
        }];

[manager.operationQueue addOperation:operation];

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iOS开发小白一枚, 每太明白题主意思.
练习的时候还真没使用到AFJSONRequestOperation, 一直都是用下面的作者的Demo来请求数据的

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager GET:@"http://example.com/resources.json" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];