Google API：访问邮箱查询邮件

Question

IDE：MS Visual Studio - C#

代码截图：

ServiceAccountCredential cred;
        //UserCredential cred;
        string[] scopes = new string[] { GmailService.Scope.GmailLabels, GmailService.Scope.GmailModify, GmailService.Scope.MailGoogleCom };
        using (var stream = new FileStream(@"C:\Users\user\Downloads\iwt-mail-crm-sync-135b79aaca90.json", FileMode.Open, FileAccess.Read))
        {
            cred = ServiceAccountCredential.FromServiceAccountData(stream);
            cred.Scopes = scopes;
        }
        var gmailsvc = new GmailService(new Google.Apis.Services.BaseClientService.Initializer()
        {
            HttpClientInitializer = cred,
            ApplicationName = "Gmail immoMail Listener",
        });
        var test = cred.RequestAccessTokenAsync(CancellationToken.None).Result;
        try
        {
            var usr = gmailsvc.Users.GetProfile("me").Execute();
            var lbl = gmailsvc.Users.Labels.List("[email protected]").Execute();
            var messages = gmailsvc.Users.Messages.List("[email protected]").Execute();
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

错误截图：

错误消息：gmail 服务抛出异常。 HttpStatusCode 是 BadRequest。前提条件检查失败。

我们尝试通过 API 将 google 服务帐户连接到 google 邮箱来查询邮件。 我们获得成功的请求访问令牌，但无法查询邮箱本身。

Answer 1

前提条件失败意味着您正在尝试使用服务帐户访问Google Drive工作区帐户，但忘记委托用户

var credential = GoogleCredential.FromFile(PathToServiceAccountKeyFile)
    .CreateWithUser("[email protected]")  // delegate to user on workspace.
    .CreateScoped(new[] {DriveService.ScopeConstants.Drive});

仅通过工作区配置对服务帐户的域范围委派是不够的，您还必须声明您希望服务帐户模拟的用户。