使用 Microsoft移动应用程序中的身份验证库(MSAL)，以与Azure Active Directory B2C租户启动身份验证工作流.

Use the Microsoft Authentication Library (MSAL) in your mobile application to initiate an authentication workflow with your Azure Active Directory B2C tenant.

在iOS平台上，必须修改AppDelegate类以初始化PlatformParameters实例，如以下代码示例所示:

On the iOS platform, the AppDelegate class must be modified to initialize a PlatformParameters instance, as demonstrated in the following code example:

using Microsoft.Identity.Client;

[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
    public override bool FinishedLaunching(UIApplication app, NSDictionary options)
    {
        global::Xamarin.Forms.Forms.Init();
        LoadApplication(new App());

        var result = base.FinishedLaunching(app, options);
        App.AuthenticationClient.PlatformParameters = new PlatformParameters(UIApplication.SharedApplication.KeyWindow.RootViewController);
        return result;
    }
}

MSAL使用PlatformParameters实例来识别其运行所在的平台，以便选择特定于平台的身份验证用户体验和令牌存储机制.

The PlatformParameters instance is used by MSAL to recognize the platform on which it's running in order to select the platform-specific authentication user experience and token storage mechanism.

有关更多信息，请请参阅文档.