我正在使用 SendGrid Azure 規范進行 XUnit 測試，在 .NET CORE 應用程序中運行。我是測試世界的新手，非常了解它背后的哲學。我是負責執行電子郵件發送功能的 EmailService 類。在我的第一個測試中，我想檢查是否從 appsetting.json 文件加載了正確的配置。appsetting.json "SendGridEmailSettings": { "SendGrid_API_Key": "xxx", "SenderConfig": {   "From": "[email protected]",   "Name": "my organization" }}測試班using Xunit;using Xunit.Extensions;namespace Services.Specs{  public class EmailServiceSpec: Specification  {    protected override void Observe()    {        var configuration = Substitute.For<IConfiguration>();        Bag.Configuration = configuration;    }}public class EmailServiceShould: EmailServiceSpec{    public EmailServiceShould()    {        Observe();    }    [Fact]    public void Load_Valid_Configuration_From_AppSetting()    {        //var SendGrid_API_Key = Configuration["SendGridEmailSettings:SendGrid_API_Key"]; this doesn't work    } }}電子郵件服務配置類public interface IEmailConfig{     string SendGrid_API_Key { get; set; }    SenderEmailConfig SenderConfig { get; set; }}電子郵件服務類 public interface IEmailService{           Task SendEmail(EmailMultipleAudience email);    Task SendEmail(EmailSingleAudience email);}public class EmailData{    public string Subject { get; set; }    public string PlainTextContent { get; set; }    public string HtmlContent { get; set; }}public class EmailSingleAudience: EmailData{    public EmailAddress To { get; set; }}public class EmailMultipleAudience : EmailData{    public List<EmailAddress> To { get; set; }}