[转][分享]新封装的一个实现无刷新连动下拉列表类（最新版本）

《[分享]新封装的一个实现无刷新连动下拉列表类 》的改进版本

变化比较大：
1.改写方法的实现，降低函数的耦合度；
2.解决了上个post中提到的“注册多对下拉列表时就会产生紊乱”的问题；
3.暴露一个方法用于实现一拖n，多级联动问题，使用方法见测试代码；

一般情况下基本够用

下面是源码，欢迎拍砖 
 NoRefreshJointDDL2.cs

using System;
using System.Data;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace NoRefreshJointDDL
{
    /**//// <summary>
    /// 
    /// </summary>
    public class NoRefreshJointDDL2:System.Web.UI.Page
    {
        成员变量#region 成员变量
        private string CilentScript;
        private bool IsWrited = false;
        #endregion

        public NoRefreshJointDDL2()
        {
            CilentScript = @"<script language=""javascript""> {0} {1} </script>";
            CilentScript = String.Format(CilentScript,"RegisterScriptoylb",GetFunctionCilentScript());
        }

        /**//// <summary>
        /// 设置联动关系，通过暴露此方法来达到多级联动的目的，注意此处只能用于已注册的DropDownList
        /// </summary>
        /// <param name="driver">驱动方</param>
        /// <param name="drivener">从动方</param>
        public void SetDDLsRelation(DropDownList driver,DropDownList drivener)
        {
            string ddlDriverID = driver.ID.ToString().Trim();
            string ddlDrivenerID = drivener.ID.ToString().Trim();
            driver.Attributes["onchange"] = "javascript:changedownlist(document.Form1," + ddlDriverID + ",Array"+ddlDriverID+"," + ddlDrivenerID + ",Array"+ddlDrivenerID+");";
        }

        /**//// <summary>
        /// 注册需联动的下拉列表
        /// </summary>
        /// <param name="driver">驱动方</param>
        /// <param name="driverRelation">驱动方关系列</param>
        /// <param name="drivener">从动方</param>
        /// <param name="drivenerRelation">从动方关系列</param>
        public void RegisterDropDownList(DropDownList driver,string driverRelation,DropDownList drivener,string drivenerRelation)
        {
            string strRegisterScript = GetInitArrayScript(driver,driverRelation);
            strRegisterScript += GetInitArrayScript(drivener,drivenerRelation);
            
            //这里使用“RegisterScriptoylb”继续占位，留予下次注册下拉列表，最后注册脚本时将清除
            CilentScript = CilentScript.Replace("RegisterScriptoylb","RegisterScriptoylb "+strRegisterScript);

            SetDDLsRelation(driver,drivener);
        }
    
        /**//// <summary>
        /// 注册需联动的下拉列表
        /// </summary>
        /// <param name="driver">驱动方</param>
        /// <param name="driverRelation">驱动方关系列</param>
        /// <param name="drivener">从动方</param>
        /// <param name="drivenerRelation">从动方关系列</param>
        /// <param name="iswrite">是否直接写入客户端</param>
        public void RegisterDropDownList(DropDownList driver,string driverRelation,DropDownList drivener,string drivenerRelation,bool iswrite)
        {
            RegisterDropDownList(driver,driverRelation,drivener,drivenerRelation);
            
            if (iswrite)
            {
                WriteScriptToCilent();
                IsWrited = true;
            }
        }

        //获取初始化数组脚本
        private string GetInitArrayScript(DropDownList ddl,string driverRelation)
        {
            //驱动部分
            string strValueField    = ddl.DataValueField;        //编码列
            string strTextField        = ddl.DataTextField;        //显示列
            string strRelation        = driverRelation;            //关系列

            //数据源
            DataTable dtSource = (DataTable)(ddl.DataSource);

            //组成变量
            string ddlID = ddl.ID.ToString().Trim();
            string strCount = "count"+ddlID;
            string strArray = "Array"+ddlID;

            
            string strRegisterScript = @"
                var {0} = 0;
                {1} = new Array();";

            strRegisterScript = String.Format(strRegisterScript,strCount,strArray);
            
            //初始化数组值
            DataRow drDriver = null;
            
            for(int i = 0;i <dtSource.Rows.Count ;i++)
            {
                drDriver = dtSource.Rows[i];
                strRegisterScript += String.Format(strArray+"["+strCount+"++] = new Array(\"{0}\",\"{1}\",\"{2}\");\n", drDriver[strValueField].ToString(),drDriver[strTextField].ToString(), drDriver[strRelation].ToString());
            }

            return strRegisterScript;
        }

        //根据驱动方选择的项，初始化从动方数据
        private void InitDrivener(DropDownList driver,string driverRelation,DropDownList drivener,string drivenerRelation)
        {
            //取得数据源
            DataTable dtDriver = (DataTable)(driver.DataSource);
            DataTable dtDrivener = (DataTable)(drivener.DataSource);

            //获取选定值，并过滤从动下拉列表的数据
            int iIndex = GetSelectRowID(driver);

            DataRow drFilter = dtDriver.Rows[iIndex];
            string strRelate = drFilter[driverRelation].ToString().Trim();

            DataView dv = new DataView(dtDrivener);
            dv.RowFilter = driverRelation + "='"+strRelate+"'";

            drivener.Items.Clear();
            drivener.DataSource = dv;
            drivener.DataTextField = drivener.DataValueField;;
            drivener.DataValueField = drivener.DataTextField;
            drivener.DataBind();
        }

        //得到下拉列表选定值所在数据源行的行号
        private int GetSelectRowID(DropDownList ddl)
        {
            string strValueFiled = ddl.DataValueField;
            string strSelectValue =    ddl.SelectedValue.ToString();

            DataView dv = new DataView((DataTable)(ddl.DataSource));
            dv.Sort = strValueFiled;

            return dv.Find(strSelectValue);
        }

        //得到事件函数脚本
        private string GetFunctionCilentScript()
        {
            string strScript = @"        
            function changedownlist(myfrm,Driver,ArrayDriver,Drivener,ArrayDrivener)
            {
                var SelectedBigId,i,j,SelectDataType;
                
                for (i= Drivener.options.length-1;i>=0 ;--i)      
                {
                    Drivener.options[i] = null; 
                }
            
                SelectedBigId = Driver.options[Driver.selectedIndex].value;
            
                for (i=0;i<ArrayDriver.length;i++)
                {
                    if (SelectedBigId == ArrayDriver[i][0])
                    {
                        SelectDataType = ArrayDriver[i][2];
                        break;
                    }
                }
            
                j = 0;    
                
                for (i=0 ;i< ArrayDrivener.length ;i++)      
                {
                    if (SelectDataType == ArrayDrivener[i][2])
                    {
                        Drivener.options[j] = new Option(ArrayDrivener[i][1],ArrayDrivener[i][0]); 
                        ++j;
                    }
                }
            }";
            return strScript;
        }

        /**//// <summary>
        /// 写入脚本
        /// </summary>
        public void WriteScriptToCilent()
        {
            if (IsWrited)
            {
                throw new Exception("自定义错误信息：重复写入客户端脚本，注册联动下拉列表失败！");
            }

            //去掉占位字符串
            string strCilentScript = CilentScript.Replace("RegisterScriptoylb","");

            //将脚本写入客户端
            HttpContext.Current.Response.Write(strCilentScript);
        }
    }
}

测试代码：

protected System.Web.UI.WebControls.DropDownList ddlDrivener;
        protected System.Web.UI.WebControls.DropDownList ddlDriver2;
        protected System.Web.UI.WebControls.DropDownList ddlDrivener2;
        protected System.Web.UI.WebControls.DropDownList ddlDriver;
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            if (!IsPostBack)
            {
                DataTable dtType = new DataTable();
                dtType.Columns.Add("TypeCode");
                dtType.Columns.Add("TypeName");
                dtType.Columns.Add("DataType");

                DataTable dtValue = new DataTable("MyTable");

                dtValue.Columns.Add("ValueCode");
                dtValue.Columns.Add("ValueName");
                dtValue.Columns.Add("DataType");

                DataRow Dr = dtType.NewRow();
                Dr["TypeCode"] = "AllMoney";
                Dr["TypeName"] = "应发工资";
                Dr["DataType"] = "Num";
                dtType.Rows.Add(Dr);

                DataRow Dr1 = dtType.NewRow();
                Dr1["TypeCode"] = "Uid";
                Dr1["TypeName"] = "身份证号码";
                Dr1["DataType"] = "Char";
                dtType.Rows.Add(Dr1);

                DataRow Dr2 = dtType.NewRow();
                Dr2["TypeCode"] = "Worker";
                Dr2["TypeName"] = "行政职务";
                Dr2["DataType"] = "Meg";
                dtType.Rows.Add(Dr2);
                
                //开始添加第二个表中的内容
                DataRow Dr3 = dtValue.NewRow();
                Dr3["ValueCode"] = "=";
                Dr3["ValueName"] = "等于";
                Dr3["DataType"] = "Num";
                dtValue.Rows.Add(Dr3);

                DataRow Dr4 = dtValue.NewRow();
                Dr4["ValueCode"] = "<>";
                Dr4["ValueName"] = "不等于";
                Dr4["DataType"] = "Char";
                dtValue.Rows.Add(Dr4);

                DataRow Dr5 = dtValue.NewRow();
                Dr5["ValueCode"] = "like";
                Dr5["ValueName"] = "相似";
                Dr5["DataType"] = "Char";
                dtValue.Rows.Add(Dr5);

                DataRow Dr6 = dtValue.NewRow();
                Dr6["ValueCode"] = ">";
                Dr6["ValueName"] = "大于";
                Dr6["DataType"] = "Num";
                dtValue.Rows.Add(Dr6);


                DataRow Dr7 = dtValue.NewRow();
                Dr7["ValueCode"] = "=";
                Dr7["ValueName"] = "否";
                Dr7["DataType"] = "Meg";
                dtValue.Rows.Add(Dr7);

                DataRow Dr8 = dtValue.NewRow();
                Dr8["ValueCode"] = "=";
                Dr8["ValueName"] = "是";
                Dr8["DataType"] = "Meg";
                dtValue.Rows.Add(Dr8); 

                

                ddlDriver.DataSource = dtType;
                ddlDriver.DataTextField = "TypeName";
                ddlDriver.DataValueField = "TypeCode";
                ddlDriver.DataBind();

                ddlDriver.SelectedIndex = 2;

                ddlDrivener.DataSource = dtValue;
                ddlDrivener.DataTextField ="ValueName";
                ddlDrivener.DataValueField = "ValueCode";
                ddlDrivener.DataBind();

                ddlDriver2.DataSource = dtType;
                ddlDriver2.DataTextField = "TypeName";
                ddlDriver2.DataValueField = "TypeCode";
                ddlDriver2.DataBind();

                ddlDriver2.SelectedIndex = 1;

                ddlDrivener2.DataSource = dtValue;
                ddlDrivener2.DataTextField ="ValueName";
                ddlDrivener2.DataValueField = "ValueCode";
                ddlDrivener2.DataBind();
                
                NoRefreshJointDDL2 uc = new NoRefreshJointDDL2();
                uc.RegisterDropDownList(ddlDriver,"DataType",ddlDrivener,"DataType");
                uc.RegisterDropDownList(ddlDriver2,"DataType",ddlDrivener2,"DataType",true);

                //--------------------下面设置可出现一拖二，多级连动效果，测试时可逐个设置
                //设置出现一拖二
                uc.SetDDLsRelation(ddlDriver,ddlDrivener2);

//                //设置出现多级连动
//                uc.SetDDLsRelation(ddlDriver,ddlDriver2);
            }

源码下载：NoRefreshJointDDL2.0.rar
转:http://hedonister.cnblogs.com/archive/2005/07/11/190566.html