如何将XML作为XML Web服务的输入并接收XML作为输出

Question

我想将XML文件作为输入发送到XML Webservice并以XML格式接收输出。

以下代码是我第一次尝试：

XmlDocument node = new XmlDocument();
node.LoadXml("<IDV>" +
    "<start_date>" + "25/12/2014" + "</start_date>"<br>
    "<vehicle_class_cd>" + "45" + "</vehicle_class_cd>"
    "<RTOLocation>" + "10416" + "</RTOLocation>"
    "<vehiclemodelcode>" + "22647" + "</vehiclemodelcode>"
    "<manufacturer_code>" + "12474" + "</manufacturer_code>"
    "<purchaseregndate>" + "27" + "</purchaseregndate>"
    "<manufacturingyear>" + "2014" + "</manufacturingyear>"       
    "</IDV>");

demo.Service src = new demo.Service();
var str = src.getIDV(node.ToString());