WPF应用基于MSAL与Graph API实现SSO时，浏览器未启动login.microsoftonline.com

我正在使用MSAL和Microsoft Graph API为WPF应用启用SSO认证，目前已成功获取令牌与用户信息，认证流程可正常完成，但浏览器并未启动https://login.microsoftonline.com页面。以下是我的代码示例：

private readonly HttpClient _httpClient = new HttpClient();
private static readonly string AadInstance = "https://login.microsoftonline.com/{0}/v2.0";
private static readonly string Tenant = "tenantid ";
private const string ClientId = "client id";
private static readonly string Authority = string.Format(CultureInfo.InvariantCulture, AadInstance, Tenant);
private IPublicClientApplication _app;

// Acquire Access Token from AAD for Proxy Application
IPublicClientApplication clientApp = PublicClientApplicationBuilder
.Create(ClientId)
//.WithDefaultRedirectUri() // will automatically use the default Uri for native app
.WithRedirectUri("mydesktopapp://auth")
.WithAuthority(Authority)
.Build();

AuthenticationResult authResult = null;
var accounts = await clientApp.GetAccountsAsync();
IAccount account = accounts.FirstOrDefault();

IEnumerable<string> scopes = new string[] { "User.Read", "openid" };

try
{               
    authResult = await clientApp.AcquireTokenSilent(scopes, account).ExecuteAsync();
}
catch (MsalUiRequiredException ex)
{
    authResult = await clientApp.AcquireTokenInteractive(scopes).ExecuteAsync();
   
}

核心原因是静默认证流程成功执行，未触发交互式认证，因此不会弹出浏览器登录页面。具体处理方式如下：

• 静默认证优先逻辑：代码先尝试AcquireTokenSilent，如果本地存在有效缓存的令牌或账户会话，会直接获取令牌，不会进入MsalUiRequiredException分支，自然不会调用AcquireTokenInteractive弹出浏览器。
• 强制触发交互式认证：若需每次都弹出浏览器（如测试场景），可直接调用AcquireTokenInteractive，或先清除本地缓存账户再执行认证：

  // 清除所有缓存账户
  foreach (var acc in accounts)
  {
      await clientApp.RemoveAsync(acc);
  }
  // 执行交互式认证
  authResult = await clientApp.AcquireTokenInteractive(scopes).ExecuteAsync();
  

• 检查缓存状态：若想保留静默逻辑但确认缓存情况，可在认证前打印账户信息：

  var accounts = await clientApp.GetAccountsAsync();
  if (accounts.Any())
  {
      Debug.WriteLine("存在缓存账户，将尝试静默认证");
  }
  else
  {
      Debug.WriteLine("无缓存账户，将触发交互式认证");
  }
  

• 验证重定向URI配置：确保Azure AD应用注册中已添加mydesktopapp://auth作为"移动和桌面应用"类别的重定向URI，避免后续回调异常。

内容的提问来源于stack exchange，提问作者Himanshu Pal