WebMethod的Ajax调用未返回响应

Question

我有一个简单的代码，可以使用WebMethod通过简单的Ajax调用来更新数据库，但不能在数据库中进行更新。

HTML标记

<a href="#" class="newProject" id ="<%= item2 %>"><i class="fa fa-file"></i> <%= item2 %></a>

客户端方法：

<script type="text/javascript">
        $(".newProject").on("click", function () {
            $.ajax({
                type: "POST",
                url: "index.aspx/UpdateCode",
                data: 'engCode=' + this.id,
                success: function (response) {
                    // window.location.reload();
                    alert(response);
                }
            });
            return false;
        });

</script>

服务器端方法：

     [WebMethod]
    public static int UpdateCode(string Code)
    {

        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("Codes"))
            {
                int intresult = 0;
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.Add("@Mode", SqlDbType.VarChar, 50).Value = "UpdateCodes";
                cmd.Parameters.Add("@Code", SqlDbType.VarChar, 50).Value = Code;

                cmd.Connection = con;
                try
                {
                    con.Open();

                    intresult = cmd.ExecuteNonQuery();
                }
                catch (SqlException ex)
                {
                    ex.ToString();
                }
                finally
                {
                    cmd.Dispose();
                    if (con != null)
                    {
                        con.Close();
                    }
                }
                return intresult;
            }
        }
    }

它在超链接的click事件上发布正确的值，但不更新数据库。

Answer 1

ASP.NET WebMethods仅将JSON作为数据格式使用：

在您的Ajax通话中，您需要添加

dataType: "json",

并以JSON形式提供数据：

data: {"engCode":this.id},

Answer 2

您没有以正确的格式传递数据。 尝试这个

<script type="text/javascript">
        $(".newProject").on("click", function () {
            $.ajax({
                type: "POST",
                url: "index.aspx/UpdateCode",
                data: {Code: this.id}
                success: function (response) {
                    // window.location.reload();
                    alert(response);
                }
            });
            return false;
        });

</script>

Answer 3

也尝试此代码。

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="JavaScriptSample._Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>How to call CSharp function in Ajax | JavaScript Sample</title>

    <script type="text/javascript">
        function getServerTime() {
            /// <summary>
            /// Call ServerTime web method via ajax request
            /// </summary>
            if (window.XMLHttpRequest) {
                // for IE7+, Firefox, Chrome, Opera, Safari
                this.xmlhttp = new XMLHttpRequest();
            }
            else {
                // for IE6, IE5
                try {
                    this.xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
                } catch (e1) {
                    try {
                        // older version of Msxml
                        this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
                    } catch (e2) {
                        this.xmlhttp = null;
                    }
                }
            }
            xmlhttp.onreadystatechange = function() {
                /// <summary>
                /// Display server time when success
                /// </summary>
                if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                    // success Status
                    document.getElementById("ServerTimeResponse").innerHTML = xmlhttp.responseText;
                }
            }
            this.xmlhttp.open("POST", "AjaxServer.asmx/ServerTime", true);
            this.xmlhttp.send();
        }
    </script>

</head>
<body>
    <form id="ServerTimeForm" runat="server">
    <div>
        <input id="ServerTimeButton" type="button" onclick="getServerTime();" value="Get Server Time" />
        <div id="ServerTimeResponse" runat="server">
        </div>
    </div>
    </form>
</body>
</html>