jquery+json实现数据二级联动的方法

function GetCityInfo1() {   $("#ddlCITY1").empty();   //$("#ddlCOUNTY").empty();   var strId = $("#ddlPROVINCE1").attr("value");   $('#HiddenPro').val(strId);   $.get("../ashx/GetCityInfo.ashx",{ProID:strId,date:new Date().getTime(),proType:"getCity"},function(result)   {    $("#ddlCITY1").append($("<option></option>").val("0").html("--请选择城市--"));    var datas=eval(result);    for(var j in datas)    {     $("#ddlCITY1").append($("<option></option>").val(datas[j].ccode).html(datas[j].cityname));    }     //获取区的信息    //GetCountryInfo();   }); }

if (context.Request.QueryString["ProID"] != null && context.Request.QueryString["proType"] != null) {   string pcode = Convert.ToString(context.Request.QueryString.GetValues("ProID")[0]);   string strSQL = "select cityname,ccode from CD_CityInfo where pcode='" + pcode + "' ";   //执行T-SQL语句 返回DataTable   DataTable dt = Snell.SnCode.DataBase.SQLServerHelper.Query(strSQL).Tables[0];   StringBuilder sb = new StringBuilder();   sb.Append(CreateJsonParameters(dt));   //根据省份编号获取信息 获取信息   if (sb.Length > 0)   {    context.Response.ClearContent();    context.Response.ContentEncoding = System.Text.Encoding.UTF8;    context.Response.Write(sb.ToString());    context.Response.End();   } }#region 根据Datatable的数据结构转换成json数据 public string CreateJsonParameters(DataTable dt) {  System.Text.StringBuilder sb = new System.Text.StringBuilder();  if (dt != null && dt.Rows.Count > 0)  {   sb.Append("[");   for (int i = 0; i < dt.Rows.Count; i++)   {    sb.Append("{");    for (int j = 0; j < dt.Columns.Count; j++)    {     //如果值不是最后一个则添加逗号分隔    if (j < dt.Columns.Count - 1)     {      sb.Append("/"" + dt.Columns[j].ColumnName.ToString() + "/":" + "/"" + dt.Rows[i][j].ToString() + "/",");     }     //如果值为最后个字符则不添加逗号    else if (j == dt.Columns.Count - 1)     {      sb.Append("/"" + dt.Columns[j].ColumnName.ToString() + "/":" + "/"" + dt.Rows[i][j].ToString() + "/"");     }    }    //如果为最后一个值的话 则不添加逗号   if (i == dt.Rows.Count - 1)    {     sb.Append("}");    }    else    {     sb.Append("},");    }   }   sb.Append("]");   return sb.ToString();  }  else { return null; } } #endregion