昨天申请的第三方客户端API通过了，今天上手开发，结果第一步就卡住了。。。

我先用博客园发给我的 ClientId 和 ClientSecret 去做 Client_Credentials授权 的测试，博客园提供的 apizza 和 postman 测试能通过，但是我写的代码测试过不了，均返回400错误，目测应该是json格式哪里错了？

下面贴下json数据模型的代码

public class CredentialsRequest
{
    [JsonProperty("client_id")]
    public string ClientID { get; set; }

    [JsonProperty("client_secret")]
    public string ClientSecret { get; set; }
        
    [JsonProperty("grant_type")]
    public string GrantType { get; set; }

    public CredentialsRequest()
    {
        GrantType = "client_credentials";
    }
}

http请求的代码：

public static WebRequest CreatePostRequest(string url)
{
    // 参数检查
    Prediction.IsTrue(string.IsNullOrEmpty(url), "url can not be null or empty");
    var request = WebRequest.Create(url);
    request.Method = "POST";
    return request;
}

private static void WriteRequestBody(WebRequest request , object model)
{
    // 参数检查
    Prediction.IsTrue(request == null, "request can not be null");
    Prediction.IsTrue(model == null, "model can not be null");
    var json = JsonConvert.SerializeObject(model);
    var data = Encoding.ASCII.GetBytes(json);
    request.ContentLength = data.Length;
    using (var stream = request.GetRequestStream())
    {
        stream.Write(data, 0, data.Length);
    }
}

public static HttpWebRequest CreateAutnenticationRequest()
{
    var request = CreatePostRequest(AuthenticationUrl) as HttpWebRequest;
    request.ContentType = "application/x-www-form-urlencoded";
    var model = new Net.Model.CredentialsRequest
    {
        ClientID = "不给看",
        ClientSecret = "不给看"
    };
    WriteRequestBody(request, model);
    return request;
}

最外层就是调用 CreateAutnenticationRequest() 这个方法然后获取 Response

有哪位麻烦给看看是哪边的参数错了吗？