将基于任务的C示例转换为VB.NET时出现问题

我有以下使用system.threading.tasks.task类的c方法。

public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
  {
    HttpResponseMessage response =
                             new HttpResponseMessage(HttpStatusCode.InternalServerError);
    response.Content = new StringContent(Content);
    response.RequestMessage = Request;
    return Task.FromResult(response);
  }

我在用vb.net编写上述代码时遇到一些问题。我已经尝试了以下操作,但是vs 2107显示了下面函数中最后一行的错误,它说 FromResult is not a member of Task .

问题 :对于C方法的最后一行,VB.NET中C代码的正确等价物是什么?

Public Async Function ExecuteAsync(ByVal cancellationToken As CancellationToken) As Task(Of HttpResponseMessage)
    Dim response As HttpResponseMessage = New HttpResponseMessage(HttpStatusCode.InternalServerError)
    response.Content = New StringContent(Content)
    response.RequestMessage = Request
    Return   Task.FromResult(Of HttpResponseMessage) (response) 'this line shows error
End Function

错误截图

包含此原始方法的完整C类如下所示。

public class GlobalExceptionHandler : ExceptionHandler
{
    public GlobalExceptionHandler()
    {
        //
        // TODO: Add constructor logic here
        //

    }
    public override void Handle(ExceptionHandlerContext context)
    {
        context.Result = new TextPlainErrorResult
               {
                   Request = context.ExceptionContext.Request,
                   Content = "Oops! Sorry! Something went wrong." +
                             "Our team has been informed and we will try to fix it as soon as possible."
               };
        base.Handle(context);
    }

    private class TextPlainErrorResult : IHttpActionResult
    {
        public HttpRequestMessage Request { get; set; }

        public string Content { get; set; }

        public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
        {
            HttpResponseMessage response =
                             new HttpResponseMessage(HttpStatusCode.InternalServerError);
            response.Content = new StringContent(Content);
            response.RequestMessage = Request;
            return Task.FromResult(response);
        }
    }
}

以上c代码转换后的vb.net代码如下。

Public Class GlobalExceptionHandler
    Inherits ExceptionHandler

    Public Sub New()
    End Sub

    Public Overrides Sub Handle(ByVal context As ExceptionHandlerContext)
        context.Result = New TextPlainErrorResult With {
            .Request = context.ExceptionContext.Request,
            .Content = "Oops! Sorry! Something went wrong." & "Our team has been informed and we will try to fix it as soon as possible."
        }
        MyBase.Handle(context)
    End Sub

    Private Class TextPlainErrorResult
        Implements IHttpActionResult

        Public Property Request As HttpRequestMessage
        Public Property Content As String

        Public Function ExecuteAsync(ByVal cancellationToken As CancellationToken) As Task(Of HttpResponseMessage)

            Dim response As HttpResponseMessage = New HttpResponseMessage(HttpStatusCode.InternalServerError)
            response.Content = New StringContent(Content)
            response.RequestMessage = Request

            Return new Task.FromResult(response)

        End Function
    End Class
End Class