jquery ajax调用webservice(C#)要注意的几个事项：

1、web.config里需要配置2个地方

<httpHandlers>
 <remove verb="*" path="*.asmx"/>
 <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad3e35"/>
 </httpHandlers>

在<system.web></system.web>之间加入

<webServices>
 <protocols>
 <add name="HttpPost" />
 <add name="HttpGet" />
 </protocols>
 </webServices>

2.正确地编写webserivce的代码

/// <summary>
 /// UserValidate 的摘要说明
 /// </summary>
 [WebService(Namespace = "http://tempuri.org/")]
 [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
 [System.ComponentModel.ToolboxItem(false)]
 // 若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。
 [System.Web.Script.Services.ScriptService]
 public class UserValidate : System.Web.Services.WebService
 {
 DFHon.Content.Common.rootPublic rp = new DFHon.Content.Common.rootPublic();
 [WebMethod]
 [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
 public string ValidateUserLogState()
 {
 string result = "";
 HttpCookie cookie = HttpContext.Current.Request.Cookies["DHFonMenberInfo"];
 if (cookie != null)
 {
 string username = System.Web.HttpUtility.UrlDecode(cookie["MenberName"]);
 int ipoint = 0;
 int gpoint = 0;
 try
 {
 DataTable dt = UserBll.ExecuteUserAllInfo(username);

 if (dt.Rows.Count > 0)
 {
 ipoint = int.Parse(dt.Rows[0]["iPoint"].ToString());
 gpoint = int.Parse(dt.Rows[0]["gPoint"].ToString());
 }
 }
 catch
 { }
 result = "{'user':{'id':'" + cookie["UserId"] + "','name':'" + username + "','message':'" + rp.getUserMsg(DFHon.Global.CurrentCookie.UserName) + "','ipoint':'" + ipoint.ToString() + "','gpoint':'" + gpoint.ToString() + "'}}";
 }
 else
 {
 result = "{'user':{'id':'0','name':'','message':'0','ipoint':'0','gpoint':'0'}}";
 }
 return result;
 }

 [WebMethod]
 [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
 public string UserLogin(string userName, string userPwd)
 {
 string returnVal = "";
 try
 {
 GlobalUserInfo info;
 DFHon.Content.UserLogin _UserLogin = new DFHon.Content.UserLogin();
 EnumLoginState state = _UserLogin.PersonLogin(HttpUtility.UrlDecode(userName), userPwd, out info);
 if (state == EnumLoginState.Succeed)
 {
 DFHon.Global.CurrentCookie.Set(info);
 DFHon.API.PDO.DiscuzNT.PassportLogin.UserLogin(Server.UrlDecode(userName), userPwd, -1);
 int ipoint = 0;
 int gpoint = 0;
 DataTable dt = UserBll.ExecuteUserAllInfo(userName);

 if (dt.Rows.Count > 0)
 {
 ipoint = int.Parse(dt.Rows[0]["iPoint"].ToString());
 gpoint = int.Parse(dt.Rows[0]["gPoint"].ToString());
 }
 returnVal = "{'user':{'id':'" + info.UserId.ToString() + "','name':'" + info.UserName + "','message':'" + rp.getUserMsg(userName) + "','ipoint':'" + ipoint.ToString() + "','gpoint':'" + gpoint.ToString() + "'}}";
 }
 else
 {
 int ids = 0;//状态：-2用户被锁定 -1用户名密码错误
 switch (state)
 {
 case EnumLoginState.Err_Locked:
 ids = -2;
 break;
 case EnumLoginState.Err_UserNameOrPwdError:
 ids = -1;
 break;
 default:
 break;
 }
 returnVal = "{'user':{'id':'" + ids + "','name':'','message':'0','ipoint':'0','gpoint':'0'}}";
 }
 }
 catch
 {
 returnVal = "{'user':{'id':'0','name':'','message':'0','ipoint':'0','gpoint':'0'}}";
 }
 return returnVal;
 }
 [WebMethod]
 public string UserLogout()
 {
 if (HttpContext.Current.Request.Cookies["DHFonMenberInfo"] != null)
 {
 HttpCookie cookie = new HttpCookie("DHFonMenberInfo");
 cookie.Expires = System.DateTime.Now.AddDays(-1);
 cookie.Domain = DFHon.Config.BaseConfig.getV("weblogin");
 HttpContext.Current.Response.AppendCookie(cookie);
 }
 return "1";
 }
 DFHon.Content.user UserBll = new DFHon.Content.user();
 [WebMethod]
 public string ValidateUserEmail(string email)
 {
 string result = "0";//返回的结果 -2邮箱为空 -1邮箱格式不正确 0邮箱存在 1填写正确
 if (string.IsNullOrEmpty(email))
 {
 result = "-2";//邮箱为空
 }
 else if (!IsValidEmail(email))
 {
 result = "-1";//邮箱格式不正确
 }
 else if (UserBll.sel_useremail(email) > 0)
 {
 result = "0";//邮箱存在
 }
 else
 {
 result = "1";//可以注册
 }
 return result;
 }

 [WebMethod]
 public string ValidateUserName(string username)
 {
 string result = "0";//返回值：-1用户名长度为2-16;0用户名存在;1可以注册
 if (username == "" || username == null || username.Length < 2 || username.Length > 16)
 {
 result = "-1";
 }
 else if (UserBll.sel_username(username) != 0)
 {
 result = "0";
 }
 else
 {
 result = "1";
 }
 return result;
 }

 public bool IsValidEmail(string strIn)
 { // Return true if strIn is in valid e-mail format. 
 return System.Text.RegularExpressions.Regex.IsMatch(strIn, @"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$");
 }
 }

WebService