c++ - 使用libcurl中发送带cookie的请求失败了

需求

获取自己的CSDN资源下载列表的数据
步骤：
1.登录csdn(已成功)
2.获取登录成功后的cookie，并保存到本地（mycookie.txt）（也已成功）
3.使用之前获取的cookie访问CSDN资源下载列表(失败)

代码我已经精简了下，方便各位同仁测试（只要先使用其他浏览器登录下csdn，就可以得到cookie，然后，手动将得到的cookie复制到代码中就可以进行测试）

备：libcurl刚接触，碰到一个cookie问题，搞了下午，不仅焦头烂额而且还没成功，找不到失败的原因，如果大家方便的话，还麻烦帮忙小测试下,再次先感谢大家的帮忙~！

使用libcurl发送消息头（附带cookie信息）的时候，服务端返回“请先登录”的信息。
cookie信息是没错的，请会的朋友帮我看下，是不是发送cookie信息的写法有问题呢？

long writer(void *data, int size, int nmemb, string &content)
{
    long sizes = size * nmemb;
    string temp((char*)data,sizes);
    content += temp;
    return sizes;
}

bool CurlInit(CURL *&curl, const char* url,string &content)
{
    CURLcode code;
    string error;
    curl = curl_easy_init();
    if (curl == NULL)
    {
        printf( "Failed to create CURL connection\n");
        return false;
    }
    code = curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, error);
    if (code != CURLE_OK)
    {
        printf( "Failed to set error buffer [%d]\n", code );
        return false;
    }
    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
    code = curl_easy_setopt(curl, CURLOPT_URL, url);
    if (code != CURLE_OK)
    {
        printf("Failed to set URL [%s]\n", error);
        return false;
    }
    code = curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
    if (code != CURLE_OK)
    {
        printf( "Failed to set redirect option [%s]\n", error );
        return false;
    }
    //writer:回调函数
    code = curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writer);
    if (code != CURLE_OK)
    {
        printf( "Failed to set writer [%s]\n", error);
        return false;
    }
    //回调函数的参数：content
    code = curl_easy_setopt(curl, CURLOPT_WRITEDATA, &content);
    if (code != CURLE_OK)
    {
        printf( "Failed to set write data [%s]\n", error );
        return false;
    }
    return true;
}
void GetDownloadList(int pageNum)
{
    CURL *easy_handle;
    CURLcode res;
    curl_global_init(CURL_GLOBAL_ALL);
    easy_handle = curl_easy_init();
    if(easy_handle)
    {
        string content;
        //get参数
        char url[128] = {0};
        sprintf(url,"http://download.csdn.net/my/downloads/%d",pageNum);
        //http请求头
        struct curl_slist *headers = NULL;
        headers = curl_slist_append(headers,"User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64; rv:25.0) Gecko/20100101 Firefox/25.0"); //模拟浏览器
        headers = curl_slist_append(headers,"Host:download.csdn.net");
        headers = curl_slist_append(headers,"Referer:http://www.csdn.net/");
        headers = curl_slist_append(headers,"Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        headers = curl_slist_append(headers,"Accept-Language:zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3");
        headers = curl_slist_append(headers,"Accept-Encoding:gzip, deflate");
        headers = curl_slist_append(headers,"Connection:keep-alive");
        headers = curl_slist_append(headers,"Cookie:UserName=用户名;UserInfo=userinfo信息（直接从火狐浏览器抓取）");                     

        //发送http请求头
        curl_easy_setopt(easy_handle, CURLOPT_HTTPHEADER, headers);
        curl_easy_setopt(easy_handle, CURLOPT_URL, url);

        if ( !CurlInit(easy_handle,url,content) )
        {
            printf( "Failed to global init default [%d]\n" );
            return;
        }       

        //执行http请求
        res = curl_easy_perform(easy_handle);
        if(res != CURLE_OK)
            fprintf(stderr,"curl_easy_perform() failed: %s\n",curl_easy_strerror(res));

        double length = 0;
        res = curl_easy_getinfo(easy_handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD , &length);

        FILE * file = fopen("1.html","wb");
        fseek(file,0,SEEK_SET);
        fwrite(content.c_str(),1,length,file);
        fclose(file);

        //释放资源
        curl_slist_free_all(headers);
        curl_easy_cleanup(easy_handle);
    }   
    curl_global_cleanup();
}

int _tmain(int argc, _TCHAR* argv[])
{   
    GetDownloadList(1); 
    getchar();
    return 0;
}

返回信息

Python代码
注：之前使用python代码也写过一个，可以成功获取，代码也顺便贴上，借此，可以发现和C++中的http消息请求头其实是一样的

#获取之前下载的资源列表
def GetDownloadList(page):
    #get参数
    url="http://download.csdn.net/my/downloads/"+page
    #http请求头
    #经过测试,只需发送UserName和UserInfo这2个cookie值即可
    headers={"Host": "download.csdn.net",
             "User-Agent":"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:25.0) Gecko/20100101 Firefox/25.0",
             "Accept":"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
             "Accept-Language":"zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3",
             "Accept-Encoding":"gzip, deflate",
             "Referer":"http://www.csdn.net/",
             "Connection":"keep-alive",
         "Cookie":"UserName="+cookies["UserName"]+";UserInfo="+cookies["UserInfo"]

    }
    r = requests.get(url,headers = headers)
    return r.text