afnetworking中，规范json格式的代码---这样打印出来errormessage就非常的方便了，呵呵呵呵

+(void) jsonFormRequest:(NSString *)url param:(NSDictionary *)param fromBlock:(void (^)(id <AFMultipartFormData> formData))block success:(void (^)(id))success failure:(void (^)(NSError *))failure
{
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager GET:url parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {
if ([responseObject respondsToSelector:@selector(objectForKey:)]) {
[MTTAFNetworkingClient handleRequest:(NSDictionary *)responseObject success:success failure:failure];
}else
{
NSDictionary *responseDictionary = [NSJSONSerialization JSONObjectWithData:responseObject options:0 error:nil];
[MTTAFNetworkingClient handleRequest:responseDictionary success:success failure:failure];
}

} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
BLOCK_SAFE_RUN(failure,error);
}];
}
+(void) jsonFormPOSTRequest:(NSString *)url param:(NSDictionary *)param success:(void (^)(id))success failure:(void (^)(NSError *))failure{

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];
NSString *fullPath = [NSString stringWithFormat:@"%@%@",DD_URL_BASE,url];

[manager POST:fullPath parameters:param success:^(AFHTTPRequestOperation *operation, id responseObject) {

NSDictionary *responseDictionary = [NSJSONSerialization JSONObjectWithData:responseObject options:0 error:nil];
NSString *string = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
NSLog(@"%@<------",string);
[MTTAFNetworkingClient handleRequest:responseDictionary success:success failure:failure];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
if([error.domain isEqualToString:NSURLErrorDomain])
error = [NSError errorWithDomain:@"没有网络连接。" code:-100 userInfo:nil];
BLOCK_SAFE_RUN(failure,error);
}];
}