iOS中的JSON错误

Question

我需要发送json字典作为参数，我正在使用网络连接。在使用下面的代码我得到一个例外：

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; 
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json", nil]; 
    manager.requestSerializer = [AFJSONRequestSerializer serializer]; 
    manager.responseSerializer = [AFJSONResponseSerializer serializer]; 

    NSDictionary *params = @{@"email":txt_email.text,@"password":txt_password.text,@"platform":@"iphone"}; 
    NSLog(@"params:%@",params); 
    SBJsonWriter *jsonWriter=[[SBJsonWriter alloc]init]; 

    NSString *paramsDicJSONN = [jsonWriter stringWithObject:params];    
    NSString *str_url=[NSString stringWithFormat:@"%@do_signup",BaseURLlogin]; 

    [manager POST:str_url parameters:paramsDicJSONN success:^(AFHTTPRequestOperation *operation, id responseObject) { 
     NSLog(@"offerJSON: %@", responseObject); 

例外：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** +[NSJSONSerialization dataWithJSONObject:options:error:]: Invalid top-level type in JSON write' 

Answer 1

关于发送POST数据读取AFNetworking documentation。

- (AFHTTPRequestOperation *)POST:(NSString *)URLString parameters:(NSDictionary *)parameters ...

的parameters参数期望一个NSDictionary，而不是一个JSON编码NSString。最有可能只是通过params并跳过所有SBJsonWriter的代码。