总述：web方法参数中有一个对象，ref类型的，调用前不为null，调用后就为null，哪位有经验的帮我看看为什么。
类定义：
UserInfomation对象
[Serializable]
public class UserInfomation
{
private int _UserId;
private string _UserName;
private int _CompanyId;
private string _CompanyType;
private string _CompanyShortName;
private string _Password;
private int _result_code;
private string _result_remark;
public int UserId
{
get { return _UserId; }
set { _UserId = value; }
}
public string UserName
{
get { return _UserName; }
set { _UserName = value; }
}
public string CompanyType
{
get { return _CompanyType; }
set { _CompanyType = value; }
}
public int CompanyId
{
get { return _CompanyId; }
set { _CompanyId = value; }
}
public string CompanyShortName
{
get { return _CompanyShortName; }
set { _CompanyShortName = value; }
}
public string Password
{
get { return _Password; }
set { _Password = value; }
}
public int Result_Code
{
get { return _result_code; }
set { _result_code = value; }
}
public string Result_Remark
{
get { return _result_remark; }
set { _result_remark = value; }
}
public UserInfomation()
{ }
}
web方法定义：
[WebMethod]
[XmlInclude(typeof(UserInfomation))]
public int GetMsgCountByType(string strdate, ref DataTable dt, ref UserInfomation usrinfo)
调用：
public ManageWs.UserInfomation iUserInfo = new ManageWs.UserInfomation();
在这里之前 iUserInfo还不等于null
int result1 = ws.GetMsgCountByType(strDate, ref dt1,ref iUserInfo);
这句中iUserInfo就为null，请问为什么？
