通过块完成回调将 AFNetworking AFXMLRequestOperation 集成到我自己的方法中答案

【问题标题】：Integrate AFNetworking AFXMLRequestOperation into my own method with block completion callback通过块完成回调将 AFNetworking AFXMLRequestOperation 集成到我自己的方法中
【发布时间】：2012-11-04 23:05:36
【问题描述】：

我正在使用奇妙的AFNetworking 的AFXMLRequestOperation 方法。我想使用以下内容，但使用我自己的完成回调将我自己的方法包裹起来。

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://api.flickr.com/services/rest/?method=flickr.groups.browse&api_key=b6300e17ad3c506e706cb0072175d047&cat_id=34427469792%40N01&format=rest"]];
AFXMLRequestOperation *operation = [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {
  XMLParser.delegate = self;
  [XMLParser parse];
} failure:nil];
[operation start];

是否可以执行以下操作？

+ (void)makeRequestWithURL:(NSURL *)url completion:(void (^)(BOOL finished))completion {

    NSURLRequest *request = [NSURLRequest requestWithURL:url]];
    AFXMLRequestOperation *operation = [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {
        XMLParser.delegate = self;
        [XMLParser parse];
    } failure:nil];
    [operation start];

    if (completion) {
        // How can I call my cometion block when AFXMLRequestOpersation is finished?
    }

}

然后调用它：

[MyClass makeRequestWithURL:url completion^(BOOL finished){
        if (finished) {
            NSLog(@"AFNetworking Finished");
        }
}];

我可以知道AFNetworking 在我的完成块中何时完成吗？

【问题讨论】：

完成应该代表什么——成功还是失败？
假设代表成功。

标签： objective-c ios objective-c-blocks afnetworking

【解决方案1】：

只需在成功块中调用您的完成块：

+ (void)makeRequestWithURL:(NSURL *)url completion:(void (^)(BOOL finished))completion {

    NSURLRequest *request = [NSURLRequest requestWithURL:url]];
    AFXMLRequestOperation *operation = [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {
        XMLParser.delegate = self;
        [XMLParser parse];
        // call completion block here
        if (completion) {
          completion(YES);
        }

    } failure:nil];
    [operation start];
}

你还应该实现AFXMLRequestOperation的失败块。

【讨论】：

【解决方案2】：

假设无论结果如何，都会运行完成块，并且 BOOL 显示成功/失败，它需要如下所示：

NSURLRequest *request = [NSURLRequest requestWithURL:url]];
AFXMLRequestOperation *operation = [AFXMLRequestOperation XMLParserRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSXMLParser *XMLParser) {
  XMLParser.delegate = self;
  [XMLParser parse];

  if (completion) {
    completion(YES);
  }

} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, NSXMLParser *XMLParse) {

  if (completion) {
    completion(NO);
  }

}];
[operation start];

【讨论】：