要禁用AAD身份验证直线和团队时，可以使用以下代码示例：

1. 使用 Microsoft Graph SDK 进行身份验证：

// 导入所需的命名空间
using Microsoft.Graph;
using Microsoft.Identity.Client;

// 定义客户端ID和秘密
string clientId = "your_client_id";
string clientSecret = "your_client_secret";
string tenantId = "your_tenant_id";

// 创建身份验证提供程序
IConfidentialClientApplication confidentialClientApplication = ConfidentialClientApplicationBuilder
    .Create(clientId)
    .WithClientSecret(clientSecret)
    .WithAuthority($"https://login.microsoftonline.com/{tenantId}")
    .Build();

// 获取访问令牌
string[] scopes = new string[] { "https://graph.microsoft.com/.default" };
AuthenticationResult authenticationResult = await confidentialClientApplication
    .AcquireTokenForClient(scopes)
    .ExecuteAsync();

// 使用访问令牌创建 GraphServiceClient 实例
GraphServiceClient graphServiceClient = new GraphServiceClient(new DelegateAuthenticationProvider((requestMessage) =>
{
    requestMessage.Headers.Authorization = new AuthenticationHeaderValue("Bearer", authenticationResult.AccessToken);
    return Task.FromResult(0);
}));

// 禁用安全码
await graphServiceClient.Me
    .Request()
    .UpdateAsync(new User
    {
        SecurityEnabledOnly = true
    });

2. 使用 REST API 进行身份验证：

// 导入所需的命名空间
using System.Net.Http;
using System.Net.Http.Headers;

// 定义客户端ID和秘密
string clientId = "your_client_id";
string clientSecret = "your_client_secret";
string tenantId = "your_tenant_id";

// 创建 HttpClient
HttpClient httpClient = new HttpClient();
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", GetAccessToken());

// 获取访问令牌
string GetAccessToken()
{
    string authority = $"https://login.microsoftonline.com/{tenantId}";
    string resource = "https://graph.microsoft.com";
    string scope = "https://graph.microsoft.com/.default";

    string url = $"{authority}/oauth2/token";

    List> requestData = new List>()
    {
        new KeyValuePair("grant_type", "client_credentials"),
        new KeyValuePair("client_id", clientId),
        new KeyValuePair("client_secret", clientSecret),
        new KeyValuePair("resource", resource)
    };

    FormUrlEncodedContent content = new FormUrlEncodedContent(requestData);
    HttpResponseMessage response = httpClient.PostAsync(url, content).Result;
    string responseString = response.Content.ReadAsStringAsync().Result;

    JObject json = JObject.Parse(responseString);
    return json["access_token"].ToString();
}

// 禁用安全码
string endpoint = "https://graph.microsoft.com/v1.0/me";
string payload = "{\"securityEnabledOnly\": true}";

HttpContent httpContent = new StringContent(payload);
httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");

HttpResponseMessage updateResponse = httpClient.PatchAsync(endpoint, httpContent).Result;

请注意，这些示例假设你已经正确设置了应用程序的权限和访问令牌，并正确配置了租户ID、客户端ID和客户端秘密。在实际使用时，请根据你的环境进行相应调整。