JS调用ashx文件传递中文参数取不到值的解决方案

实现在text中输入数据，areatext里动态搜索

        <th class="t_r">
                                            请选择公司：
                                        </th>
                                        <td width="89%" class="kuang1">
                                            <asp:TextBox ID="txtKeyWord" runat="server"></asp:TextBox>
                                            <span class="red">*</span><br />
                                            <select id="txtCompanyList" multiple="multiple" name="D1" onclick="CompanySelect()"
                                                style=" 380px; height: 119px">
                                                <option></option>
                                            </select>
                                        </td>

JS:

function BindCompanyList() {
            var comapyname = $("#txtKeyWord").val();
            $("#txtCompanyList").html("");
            $.getJSON("GetCompanyList.ashx?companyname=" + escape(comapyname), null, function(json) {
                if (json != null) {
                    $.each(json, function(i) { $("#txtCompanyList").append($("<option></option>").val(json[i].id).html(json[i].companyname)) });
                }
            });
        }
        function CompanySelect() {
            var Obj = document.getElementById("txtCompanyList");
            if (document.getElementById("txtCompanyList").options.length != 0) {
                document.getElementById("txtKeyWord").value = Obj.options[Obj.selectedIndex].text;
            }
        }

ASHX:

        public void ProcessRequest(HttpContext context)
        {
            StringBuilder sb=new StringBuilder();
            if (context.Request.Params["companyname"] != null)
            {
                DataTable dt = null;
                string strcompanyname = context.Server.HtmlDecode(context.Request.Params["companyname"].ToString());
                if (strcompanyname!="")
                {
                    dt = new BLL.CZL_CompanyInfo().GetList(" companyname like '%" + strcompanyname + "%'").Tables[0];
                }
                else
                {
                    dt = new BLL.CZL_CompanyInfo().GetAllList().Tables[0];
                }
                if (dt == null || dt.Rows.Count == 0)
                {
                    return;
                }
                else
                {
                    sb.Append("[");
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        //返回JOSN数据
                        sb.Append("{\"id\":\"" + dt.Rows[i]["id"].ToString() + "\",\"companyname\":\"" +Common.ProductAbout.ReturnStr(dt.Rows[i]["companyname"].ToString()) + "\"},");
                    }
                    sb.Remove(sb.Length - 1, 1);
                    sb.Append("]");
                }
            }
            context.Response.ContentType = "application/json";
            context.Response.ContentEncoding = Encoding.UTF8;
            context.Response.Write(sb.ToString());
        }

注意传递值的时候，js里用escape()对参数进行编码

取得的时候，.cs中用context.Server.HtmlDecode()进行对参数的解密