为什么创建令牌时会创建错误

Question

 public static void CreateToken()
    {

        HttpClient client = new HttpClient();
        client.DefaultRequestHeaders.Add("grant_type", "client_credentials");
        var UserPassJson = "{\"username\": \"mucode\",\"password\": \"mypassword\"}";

        HttpContent content = new StringContent(UserPassJson, Encoding.UTF8, "application/json");

        var response = client.PostAsync(new Uri("https://api.sandbox.paypal.com/v1/oauth2/token"), content).Result;
        if (response.IsSuccessStatusCode)
        {
            var responseContent = response.Content;
            string responseString = responseContent.ReadAsStringAsync().Result;
            Console.WriteLine(responseString);
        }
    }

为什么 response.IsSuccessStatusCode 显示状态码 401？什么原因导致故障？ 什么操作会导致成功？

Answer 1

documentation 指定您应该使用basic authentication 传递用户名和密码，并且您应该传递一个包含grant_type=client_credentials 的表单编码正文。

目前，您的代码将 grant_type 添加为标题，并将用户名和密码作为 JSON 对象发布在正文中。

更正您的代码以按照文档所述的方式进行操作，我们得到：

HttpClient client = new HttpClient();
byte[] authBytes = System.Text.Encoding.ASCII.GetBytes("mucode:mypassword");
string base64Auth = Convert.ToBase64String(authBytes);
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", base64Auth);

HttpContent content = new FormUrlEncodedContent(new[] { new KeyValuePair<string, string>("grant_type", "client_credentials") });

var response = client.PostAsync(new Uri("https://api.sandbox.paypal.com/v1/oauth2/token"), content).Result;
if (response.IsSuccessStatusCode)
{
    var responseContent = response.Content;
    string responseString = responseContent.ReadAsStringAsync().Result;
    Console.WriteLine(responseString);
}

附：我建议阅读You're using HttpClient wrong and it is destabilizing your software 和后续You're (probably still) using HttpClient wrong and it is destabilizing your software。我还建议使用此方法async 并将链一直向上设置async。