ASP.NET中利用JQuery AJAX修改用户密码

一、新建数据库，在项目App_Data右击，添加一个数据库，新建一个UserInfo表，表里设UserName，Password两个字段

二、新建一个Default.aspx页面，用表格简单布局，代码如下

<body>
    <form id="form1" runat="server">
    <table>
        <tr>
            <td>
                旧密码：
            </td>
            <td>
                <asp:TextBox ID="txtOldPass" runat="server"></asp:TextBox><asp:RequiredFieldValidator
                    ID="RequiredFieldValidator1" runat="server" ErrorMessage="RequiredFieldValidator"
                    ControlToValidate="txtOldPass">*</asp:RequiredFieldValidator><span id="msg"></span>
            </td>
        </tr>
        <tr>
            <td>
                新密码：
            </td>
            <td>
                <asp:TextBox ID="txtNewPass" runat="server"></asp:TextBox><asp:RequiredFieldValidator
                    ID="RequiredFieldValidator2" runat="server" ErrorMessage="RequiredFieldValidator"
                    ControlToValidate="txtNewPass">*</asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td>
                确认新密码：
            </td>
            <td>
                <asp:TextBox ID="txtConfirmPass" runat="server"></asp:TextBox><asp:RequiredFieldValidator
                    ID="RequiredFieldValidator3" runat="server" ErrorMessage="RequiredFieldValidator"
                    Display="Dynamic" ControlToValidate="txtConfirmPass">*</asp:RequiredFieldValidator><asp:CompareValidator
                        ID="CompareValidator1" runat="server" ErrorMessage="CompareValidator" ControlToCompare="txtNewPass"
                        ControlToValidate="txtConfirmPass">两次密码不一致</asp:CompareValidator>
            </td>
        </tr>
        <tr>
            <td colspan="2" align="center">
                <asp:Button ID="btnModify" runat="server" Text="修改" />
            </td>
        </tr>
    </table>
    </form>
</body>

三、新建一个WebService，名为：CheckPassword.asmx，注意将 [System.Web.Script.Services.ScriptService]这个取消注释

代码如下：

/// <summary>
   /// CheckPassword 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 CheckPassword : System.Web.Services.WebService
   {
 
       [WebMethod]
       public string IsCorrectPass(string username, string password)
       {
           string connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
           string word = "";
           using (SqlConnection conn = new SqlConnection(connStr))
           {
               using (SqlCommand cmd = new SqlCommand(string.Format("select password from UserInfo where UserName='{0}'", username), conn))
               {
                   conn.Open();
                   word = cmd.ExecuteScalar().ToString();
                   if (word == password)
                   {
                       return "密码正确";
                   }
                   else
                   {
                       return "密码错误";
                   }
               }
           }
       }
   }

四、Default.aspx页面里加入以下JS代码

<script type="text/javascript">
    $(function() {
        $("#<%=txtOldPass.ClientID %>").blur(function() {
            $.ajax({
                type: "POST",
                contentType: "application/json",
                url: "CheckPassword.asmx/IsCorrectPass",
                data: "{username:'admin',password:'" + $(this).val() + "'}",      //这里为了方便用户名就只有一个，
                dataType: "json",                                                 //数据库里也就一条数据
                success: function(result) {
                    $("#msg").text(result.d);
                }
            });                                                 
        });
    });
</script>