DELPHI：“无效的属性元素：系统”

Question

我正在使用WSDL，当我尝试执行其中一个方法时，我收到错误

  

..引发异常类EPropertyConvertError，消息＆＃39;无效   property element：System＆＃39;

任何想法是什么原因造成的？

这是我正在运行的代码（cEPS_ *是前面代码中定义的常量）：

procedure TForm1.Button1Click(Sender: TObject);
var
  Headers : ISOAPHeaders;
  aResult: c_ExpressPSAPI.Response;
begin
  try
    FEPS_SoapService := c_ExpressPSAPI.GetExpressSoap();
    FEPS_Headers := (FEPS_SoapService as ISOAPHeaders);

    FEPS_Application := c_ExpressPSAPI.Application.Create();
    FEPS_Application.ApplicationID := cEPS_ApplicationID;
    FEPS_Application.ApplicationName := cEPS_ApplicationName;
    FEPS_Credentials := c_ExpressPSAPI.Credentials.Create();
    FEPS_Credentials.AccountID := cEPS_AccountID;
    FEPS_Credentials.AccountToken := cEPS_AccountToken;
    FEPS_Credentials.AcceptorID := cEPS_AcceptorID;
    FEPS_Credentials.NewAccountToken := '';


    aResult := c_ExpressPSAPI.Response.Create;
    aResult := FEPS_SoapService.HealthCheck(FEPS_Credentials, FEPS_Application);

  except
    on E : ERemotableException do
      ShowMessage(E.ClassName + ' error raised, with message : ' + E.FaultDetail + ' :: '
                    + E.Message);

  end;

end;

这是WSDL代码：

  ExpressSoap = interface(IInvokable)
  ['{83D77575-DBDE-3A05-D048-60B2F6BCDFE6}']
    function  HealthCheck(const credentials: Credentials; const application: Application): Response; stdcall;