调用令牌的Microsoft Graph API会出现错误“ AADSTS900144：请求正文必须包含以下参数：'grant_type'

问题：我已成功复制了您的错误。如下所示：

解：

您正在以错误的方式尝试。您必须form-data使用key-value pairs以下格式在邮递员上发送必需的参数：

grant_type:client_credentials
client_id:b6695c7be_YourClient_Id_e6921e61f659
client_secret:Vxf1SluKbgu4PF0Nf_Your_Secret_Yp8ns4sc=
scope:https://graph.microsoft.com/.default

代码段：

  //Token Request End Point
    string tokenUrl = $"https://login.microsoftonline.com/YourTenant.onmicrosoft.com/oauth2/v2.0/token";
    var tokenRequest = new HttpRequestMessage(HttpMethod.Post, tokenUrl);

    //I am Using client_credentials as It is mostly recommended
    tokenRequest.Content = new FormUrlEncodedContent(new Dictionary<string, string>
    {
        ["grant_type"] = "client_credentials",
        ["client_id"] = "b6695c7be_YourClient_Id_e6921e61f659",
        ["client_secret"] = "Vxf1SluKbgu4PF0Nf_Your_Secret_Yp8ns4sc=",
        ["scope"] = "https://graph.microsoft.com/.default" 
    });

    dynamic json;
    AccessTokenClass results = new AccessTokenClass();
    HttpClient client = new HttpClient();

    var tokenResponse = await client.SendAsync(tokenRequest);

    json = await tokenResponse.Content.ReadAsStringAsync();
    results = JsonConvert.DeserializeObject<AccessTokenClass>(json);

使用的班级：

public class AccessTokenClass
   {
        public string token_type { get; set; }
        public string expires_in { get; set; }
        public string resource { get; set; }
        public string access_token { get; set; }
   }

你可以参考官方文件

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