VS2019中写程序关编译成dll

代码如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using XMLDaClientdll.XMLWrapper;

namespace XMLDaClientdll
{
    public interface IXMLDaClientdll
    {
        string Connect(string txtUrl);
    }
    public class ConnectClass:IXMLDaClientdll
    {
        public string Connect(string txtUrl)
        {
            XMLWrapper.OPC_XML_DA_WrapperService service = new XMLWrapper.OPC_XML_DA_WrapperService();
            service.Url = "http://" + txtUrl + "/soap";

            ReplyBase reply;
            ServerStatus Status;
            try
            {
                reply = service.GetStatus("en-US", "", out Status);
                return Status.StatusInfo.ToString();
            }
            catch (Exception excp)
            {
                return excp.Message;

            }
            finally
            {
            }
        }
    }
}

狐表中引用此dll，全局代码中写

Public Declare Function connectxml Lib "XMLDaClientdll.dll" Alias "Connect" (ByVal txtUrl As String) As String  

测试Output.Show(connectxml("192.168.1.222"))

报错

此主题相关图片如下：1.png

不知道要修改哪里？偶是小白，C#看了一周多，还是云里雾里的。

提示错误

---------------------------
错误
---------------------------
编译错误:“Connect”不是“XMLDaClientdll”的成员。

错误代码：Output.Show(XMLDaClientdll.Connect("192.168.1.222"))
---------------------------
确定  
---------------------------

可以了，谢谢！