Jquery with Ajax 用户名是否存在 简单处理

 

在注册 的时候可以用到。

from page code

 

 <script type="text/javascript">

        function ShowAvailability() {
            $("#nameMsg").html = "";
         
            var name = $('#<%=userName.ClientID%>').val();
            if (name === "") {
                $("#nameMsg").css("color", "red");
                $("#nameMsg").html ("*Please input userName");
            }
            else {
                $.ajax({
                    type: "Get",
                    url: "Handler/GetUserHandler.ashx",
                    //  data: '{userName: "' +name + '" }',
                    data: { "userName": name },
                    contentType: "application/json; charset=utf-8",
                    dataType: "json",
                    success: OnSuccess,
                    failure: function (response) {
                        alert(response);
                    }
                });
            }
        }
        function OnSuccess(response) {
          
            if (response == "1") {
                $("#nameMsg").css("color", "green");
                $("#nameMsg").html("Available");
            }
            else {
                $("#nameMsg").css("color", "red");
                $("#nameMsg").html("UserName already used by others, please rename it.");
            }
            //            switch (response) {
            //                case "true":
            //                    mesg.style.color = "green";
            //                    mesg.html = "Available";
            //                    break;
            //                case "false":
            //                    mesg.style.color = "red";
            //                    mesg.html = "Not Available";
            //                    break;
            //                case "error":
            //                    mesg.style.color = "red";
            //                    mesg.html = "Error occured";
            //                    break;
            //            }
        }

    </script>

 

 <tr>
                                    <th scope="row">
                                        用户名：
                                    </th>
                                    <td>
                                        <asp:TextBox ID="userName" runat="server" CssClass="input-normal" onblur="ShowAvailability();"></asp:TextBox>
                                        <span id="nameMsg"></span>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" ForeColor="Red" ControlToValidate="userName"
                                            runat="server" ErrorMessage="用户名不能为空"></asp:RequiredFieldValidator>
                                    </td>
                                    <%--                            <td><input value="" type="text" name="userName" id="userName" class="input-normal" /></td>--%>
                                </tr>

 

 

事件处理程序

<%@ WebHandler Language="C#" Class="GetUserHandler" %>

using System;
using System.Web;

public class GetUserHandler : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "text/plain";
       // context.Response.Write("Hello World");
        string userName = context.Request.QueryString["userName"];
        if (userName.Length > 4)
        {
            context.Response.Write("1");
        }
        else
        {
            context.Response.Write("0");
        }
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}

 

 Ajax 用json传递对象,未通过测试，空了继续。

 

 $(document).ready(function () {
        $('#btnregister').click(function () {
            var obj = { username: $("#txtuser").val(), name: $("#txtname").val() };
            $.ajax({
                type: "POST",
                contentType: "application/json; charset=utf-8",
                url: "fetchusers.asmx/RegUsers",
                data: JSON.stringify(obj),
                dataType: "json",
                success: function (data) {
                    alert("Successfully register");
                    $("#btnregclose").click();
                }
            });
        });
    });

 

c# code

[WebMethod]
        public string RegUsers(string username, string name)
        {
            string response = username + name;

            return response;
        }