外部应用向Azure AD B2C添加用户时遇System.NullReferenceException问题

架构老林

2026-6-24

Azure AD B2C 用户创建时抛出NullReferenceException问题

我正在开发一款管理应用，可对Azure AD B2C租户执行用户查看、删除及新增操作。但执行AddAsync(newUser)代码时，持续抛出System.NullReferenceException异常。已确认应用拥有Azure的read.write权限，tenantId、AppID及客户端密钥均正确，且已更新所有包和.NET环境。

代码片段

public static async Task CreateUser(GraphServiceClient graphClient)
{
    Console.WriteLine("Creating a new user...");

    // 收集新用户信息输入
    Console.Write("输入显示名称: ");
    string displayName = Console.ReadLine();

    Console.Write("输入名字: ");
    string givenName = Console.ReadLine();

    Console.Write("输入姓氏: ");
    string surname = Console.ReadLine();

    Console.Write("输入邮箱地址: ");
    string emailAddress = Console.ReadLine();

    Console.Write("输入密码: ");
    string password = Console.ReadLine();


    var newUser = new UserModel
    {
        DisplayName = displayName,
        GivenName = givenName,
        Surname = surname,
        Password = password,
        Identities = new List<ObjectIdentity>
        {
            new ObjectIdentity
            {
                SignInType = "emailAddress",
                IssuerAssignedId = emailAddress
            }
        }
    };

    try
    {
        var createdUser = await graphClient.Users
            .Request()
            .AddAsync(newUser);

        Console.WriteLine($"用户 '{createdUser.DisplayName}' 创建成功，ID: '{createdUser.Id}'。");
    }
    catch (Exception ex)
    {
        Console.ForegroundColor = ConsoleColor.Red;
        Console.WriteLine($"创建用户出错: {ex.Message}");
        Console.ResetColor();
    }
}