AFJSONRequestOperation：变量“操作”在被块捕获时未初始化

Posted 2023-03-16

【中文标题】AFJSONRequestOperation：变量“操作”在被块捕获时未初始化

【英文标题】：AFJSONRequestOperation : variable 'operation' is uninitialized when captured by block

【发布时间】：2013-12-17 09:06:00

【问题描述】：

我在第 6 行的此代码中收到上述警告，并且 userInfo 在块中也变为 nil。请提出一些建议以删除此警告和 userInfo 问题。

AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:@"some url"]];
[httpClient registerHTTPOperationClass:[AFJSONRequestOperation class]];
[httpClient setParameterEncoding:AFJSONParameterEncoding];
[httpClient setDefaultHeader:@"Accept" value:@"application/json"];
NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST" path:path parameters:parameters];
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSDictionary* JSON)
                                     
                                         [self.delegate didReceivedResponse:JSON withUserInfo:operation.userInfo];                                             
                                      failure:^(NSURLRequest *request, NSHTTPURLResponse *response,
                                                 NSError *error, id JSON)
                                     
                                         NSLog(@"Network : %@",error);
                                         [self.delegate didFailWithError:error withUserInfo:operation.userInfo];
                                     ];
operation.userInfo = userInfo;
[operation start];

【参考方案1】：

只需在创建操作时使用 userInfo 变量，而不是调用 operation.userInfo - 在您创建它时它并不存在。

AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:@"some url"]];
[httpClient registerHTTPOperationClass:[AFJSONRequestOperation class]];
[httpClient setParameterEncoding:AFJSONParameterEncoding];
[httpClient setDefaultHeader:@"Accept" value:@"application/json"];
NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST" path:path parameters:parameters];
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSDictionary* JSON)

    [self.delegate didReceivedResponse:JSON withUserInfo:userInfo];                                             
 failure:^(NSURLRequest *request, NSHTTPURLResponse *response,
    NSError *error, id JSON)

    NSLog(@"Network : %@",error);
    [self.delegate didFailWithError:error withUserInfo:userInfo];
];
operation.userInfo = userInfo;
[operation start];

另一种选择是稍后设置块：

AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:@"some url"]];
[httpClient registerHTTPOperationClass:[AFJSONRequestOperation class]];
[httpClient setParameterEncoding:AFJSONParameterEncoding];
[httpClient setDefaultHeader:@"Accept" value:@"application/json"];
NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST" path:path parameters:parameters];
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:nil failure:nil];
operation.userInfo = userInfo;

[operation setCompletionBlockWithSuccess:^(NSURLRequest *request, NSHTTPURLResponse *response, NSDictionary* JSON)

    [self.delegate didReceivedResponse:JSON withUserInfo:userInfo];                                             
  failure:^(NSURLRequest *request, NSHTTPURLResponse *response,
                                                 NSError *error, id JSON)
 
     NSLog(@"Network : %@",error);
     [self.delegate didFailWithError:error withUserInfo:userInfo];
 ];

[operation start];

【讨论】：

它不起作用，因为操作时没有successBlock这样的属性。

它现在工作正常，没有任何警告。非常感谢。

AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:nil failure:nil];

抱歉出现错误 - 是在没有编译器的情况下从头顶写的。我按照建议修复了，谢谢。