使用Graph API向AAD添加成员时遭遇Identifier Expected错误

使用Microsoft Graph Client（5.56版本）编写Azure Function代码，意图将用户添加到Azure Active Directory（AAD）组中，但代码中await graphClient.Groups[GroupId].Members.(userToAdd);这一行出现Identifier Expected（需要标识符）错误。以下是完整代码：

public static class AddUserToGroup
{
    [FunctionName("AddUserToGroup")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        log.LogInformation("AddUserToGroup function triggered with HTTP trigger.");

        string UserPrincipalName = req.Query["UserPrincipalName"];
        string GroupId = req.Query["GroupId"];


        string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
        dynamic data = JsonConvert.DeserializeObject(requestBody);
        UserPrincipalName = UserPrincipalName ?? data?.UserPrincipalName;
        GroupId = GroupId ?? data?.GroupId;

        string responseMessage;
        if (UserPrincipalName.IsNullOrEmpty() || GroupId.IsNullOrEmpty())
        {
            responseMessage = "Missing Parameter.";
            return new BadRequestObjectResult(responseMessage);
        }

        var scopes = new[] { "https://graph.microsoft.com/.default" };

        var builder = new ConfigurationBuilder()
                .SetBasePath(Environment.CurrentDirectory)
                .AddJsonFile("local.settings.json", true)
                .AddUserSecrets(Assembly.GetExecutingAssembly(), true)
                .AddEnvironmentVariables()
                .Build();


        var tenantId = builder.GetValue<string>("_secret:tenantId");
        var clientId = builder.GetValue<string>("_secret:clientId");
        var clientSecret = builder.GetValue<string>("_secret:clientSecret");

        // using Azure.Identity;
        var options = new TokenCredentialOptions
        {
            AuthorityHost = AzureAuthorityHosts.AzurePublicCloud
        };

        var clientSecretCredential = new ClientSecretCredential(
            tenantId, clientId, clientSecret, options);

        var graphClient = new GraphServiceClient(clientSecretCredential, scopes);


        User userToAdd = await graphClient.Users[UserPrincipalName].GetAsync();
        await graphClient.Groups[GroupId].Members.(userToAdd);

        responseMessage = "User added to the group successfully.";

        log.LogInformation("AddUserToGroup function processing finished.");
        return new OkObjectResult(responseMessage);
    }
}

使用包：Microsoft.Graph 5.56版本

1. 语法错误：出错的代码行存在语法问题，括号前多了一个.，导致编译器无法识别合法标识符。
2. API版本差异：你参考的仓库使用的是旧版Microsoft Graph SDK（v4及以下），而v5版本的API结构已变更，添加组成员不再支持直接传递用户对象。

将错误代码行替换为以下内容即可解决问题：

await graphClient.Groups[GroupId].Members.Ref.PostAsync(new Microsoft.Graph.Models.ReferenceRequestBody { Id = userToAdd.Id });

• 确保你的应用程序已在Azure AD中配置GroupMember.ReadWrite.All或Group.ReadWrite.All的应用权限，并且已获得管理员同意。
• 建议添加异常捕获逻辑，处理用户对象获取失败（如用户不存在）等场景，避免后续代码执行报错。

内容的提问来源于stack exchange，提问作者kudlatiger