> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 如何:登录用户的最佳实践

> 如何:登录用户的最佳实践

## 演示如何静默获取默认用户的示例

游戏需要建立一个初始用户。此示例展示了如何尽可能早地
完成这一步。如果你希望游戏菜单以清晰标识用户的信息
“问候”该用户,并且不希望立即
显示 UI,通常应遵循此模式。

```c++ theme={null}
HRESULT Identity_TrySignInDefaultUserSilently(_In_ XTaskQueueHandle asyncQueue)
{
    XAsyncBlock* asyncBlock = new XAsyncBlock();
    asyncBlock->queue = asyncQueue;
    asyncBlock->callback = Identity_TrySignInDefaultUserSilently_Callback;

    // Request to silently sign in the default user.
    HRESULT hr = XUserAddAsync(XUserAddOptions::AddDefaultUserSilently, asyncBlock);

    if (FAILED(hr))
    {
        delete asyncBlock;
    }

    return hr;
}

void CALLBACK Identity_TrySignInDefaultUserSilently_Callback(_In_ XAsyncBlock* asyncBlock)
{
    // NOTE: XUserAddResult will add a Ref to the passed-in XUserHandle.
    XUserHandle newUser = nullptr;
    HRESULT hr = XUserAddResult(asyncBlock, &newUser);

    if (SUCCEEDED(hr))
    {
        // TO DO: create Xbox services context and do something with that user.
        // ...
    }
    else 
    {
        // You are here because there's no default user or because of an error.
        // Display some UI, such as "Press A or Enter to continue," and try the sign-in with the UI flow.
    }

    delete asyncBlock;
}
```

## 演示如何获取初始用户的示例

与前一个示例一样,游戏需要建立一个初始用户。在此情况下,
游戏愿意在请求用户时显示 UI。仅当系统无法
确定默认用户时,才会显示 UI。

```c++ theme={null}
HRESULT Identity_TrySignInDefaultUser(_In_ XTaskQueueHandle asyncQueue)
{
    XAsyncBlock* asyncBlock = new XAsyncBlock();
    asyncBlock->queue = asyncQueue;
    asyncBlock->callback = Identity_TrySignInDefaultUser_Callback;

    // Request to silently sign in the default user.
    HRESULT hr = XUserAddAsync(XUserAddOptions::AddDefaultUserAllowingUI, asyncBlock);

    if (FAILED(hr))
    {
        delete asyncBlock;
    }

    return hr;
}

void CALLBACK Identity_TrySignInDefaultUser_Callback(_In_ XAsyncBlock* asyncBlock)
{
    // NOTE: XUserAddResult will add a Ref to the passed-in XUserHandle.
    XUserHandle newUser = nullptr;
    HRESULT hr = XUserAddResult(asyncBlock, &newUser);

    if (SUCCEEDED(hr))
    {
        // TO DO: create Xbox services context and do something with that user.
        // ...
    }
    else
    {
        // You are probably here because someone canceled out of the UI flow to 
        // sign in or an expected error occurred.
        // Display some UI, such as "Press A or Enter to continue," and try the sign-in 
        // again with the UI flow.
    }

    delete asyncBlock;
}

```

## 另请参见

[用户身份与 XUser](/build/core-features/common/user/player-identity-xuser)


## Related topics

- [用户](/zh-CN/build/core-features/common/user/user-toc.md)
- [用户身份与 XUser](/zh-CN/build/core-features/common/user/player-identity-xuser.md)
- [将 GDK 集成到 4.26 之前的 Unreal Engine 项目](/zh-CN/build/gdk-and-engines/unreal/unreal-legacy.md)
- [账户身份验证和访问概述](/zh-CN/services/xbox-services/fundamentals/identity/auth/live-authentication-overview.md)
- [调用 XBOX 服务的最佳实践](/zh-CN/services/xbox-services/develop/best-practices/live-best-practices-calling-xbl.md)