Xamarin 表单：使用 xamarin 表单 web api 进行令牌身份验证

Question

我正在为 xamarin 表单使用基于令牌的身份验证，这是我的代码

 public async Task<string> checkLogin(string username, string password)
    {




    var keyValues = new List<KeyValuePair<string, string>>
    {
        new KeyValuePair<string, string>("username",username),
        new KeyValuePair<string, string>("password",password),
                        new KeyValuePair<string, string>("grant_type","password")


    };
    var request = new HttpRequestMessage(HttpMethod.Post, "http://softsol.com.pk/Token");

    request.Content = new FormUrlEncodedContent(keyValues);

    var client = new HttpClient();

    var response = await client.SendAsync(request);
    var content = await response.Content.ReadAsStringAsync();


    JObject jdynamic = JsonConvert.DeserializeObject<dynamic>(content);
    var accessToken = jdynamic.Value<string>("access_token");
    var refershToken = jdynamic.Value<string>("refresh_token");
    var date = DateTime.Now.ToString();
    var accessTokenExpiration= jdynamic.Value< DateTime> (".expires");


    //await Application.Current.MainPage.DisplayAlert("Alert", content, "OK");
    Debug.WriteLine(content);
    Settings.AccessToken=accessToken;
    Settings.RefreshToken = refershToken;

    Settings.AccessTokenexpiration = accessTokenExpiration;
    return accessToken;
    //return response.IsSuccessStatusCode;



}

当我使用用户名和密码登录时出现此错误

Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0

如果我在邮递员中运行，它的工作正常，例如，如果我在邮递员中使用 username="test",password="test",grant-type="password" 运行这个http://softsol.com.pk/Token，我会得到令牌及其工作但我从 xamarin 表单中得到错误。我被困在这里

Answer 1

我在http://softsol.com.pk/Help 访问了您后端的API 部分，发现http://softsol.com.pk/Token 不存在。 此外，在 Postman 上进行测试会返回 JSON 响应：

{
    "error": "unsupported_grant_type"
} 

使用邮递员，我以 JSON 格式发送请求：

{"username":"test","password":"test","grant-type":"password"}

并作为 x-www-form-urlencoded ：

我建议您必须正确调试并分析豁免信息。

Answer 2

 public async void GetInfoLogin()
    {

        IEnumerable<KeyValuePair<string, string>> member = new List<KeyValuePair<string, string>>()
        {
            new KeyValuePair<string, string>("username", UserName.Text),
            new KeyValuePair<string, string>("password", PassWord.Text),
            new KeyValuePair<string, string>("action", "get_user")
        };


        HttpContent content = new FormUrlEncodedContent(member);

        HttpClient client = new HttpCLient();
        var response = await client.PostAsync("(endpoint to server)",content);

        var result = await response.Content.ReadAsStringAsync();
        var TReturn = (JObject)JsonConvert.DeserializeObject(result);
        var success = TReturn.Value<string>("success");
        var error = TReturn.Value<string>("error");
        var user_id = TReturn.Value<string>("user_id");
        var full_name = TReturn.Value<string>("full_name");
        var time = TReturn.Value<int>("time");      
        var send = TReturn.Value<string>("send");

}