谷歌PlayGamesAPI:如何在C#中验证ServerAuthCode

using Google.Apis.Auth.OAuth2;
using Google.Apis.Auth.OAuth2.Flows;
using Google.Apis.Auth.OAuth2.Web;

string clientId = "你的客户端ID";
string clientSecret = "你的客户端密钥";
string redirectUri = "你的重定向URI";

AuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow(
    new GoogleAuthorizationCodeFlow.Initializer
    {
        ClientSecrets = new ClientSecrets
        {
            ClientId = clientId,
            ClientSecret = clientSecret
        },
        Scopes = new[] { "https://www.googleapis.com/auth/games_lite" },
        DataStore = new FileDataStore("Store")
    });

AuthorizationCodeRequestUrl url = flow.CreateAuthorizationCodeRequest(redirectUri);
string authorizationUrl = url.Build();

// 将authorizationUrl返回给前端，用于用户点击进行授权

using Google.Apis.Auth.OAuth2;
using Google.Apis.Auth.OAuth2.Flows;
using Google.Apis.Auth.OAuth2.Web;

string authorizationCode = "从重定向URI中获取的授权码";

TokenResponse tokenResponse = await flow.ExchangeCodeForTokenAsync("", authorizationCode, redirectUri, CancellationToken.None);
string accessToken = tokenResponse.AccessToken;