Delphi7调用.net的webservice 传进去的参数为空

[GlzCss]

/// <summary> /// 快速通道 webservice接口 /// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
public class FastChannelServices : System.Web.Services.WebService
{ [WebMethod]
[SoapDocumentMethod(Action = "",RequestNamespace ="http://soapServer.FastChannel.fsti.com")]

public string FastChannelInterface(string requestData)

上面是.net部分

http://125.77.107.174:8090/FastChannelServices.asmx?wsdl
这个是访问的地址
请大家帮忙