动态添加控件之方案

在网上面发现了一个很好的解决方案。

using System.Web.UI.Design;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.Xml;
using System.Collections;
using System.Web;
using System;
namespace cn.co
{


    [ToolboxData("<{0}:DynamicControlsPanel runat=server></{0}:DynamicControlsPanel>")]

    public class DynamicControlsPanel : Panel
    {
        自定义的属性#region 自定义的属性


        [DefaultValue(HandleDynamicControls.DontPersist)]
        public HandleDynamicControls ControlsWithoutIDs
        {
            get
            {
                if (ViewState["ControlsWithoutIDs"] == null)
                    return HandleDynamicControls.DontPersist;
                else
                    return (HandleDynamicControls)ViewState["ControlsWithoutIDs"];
            }
            set { ViewState["ControlsWithoutIDs"] = value; }
        }

        #endregion 自定义的属性

        视图状态管理#region 视图状态管理

        protected override void LoadViewState(object savedState)
        {
            object[] viewState = (object[])savedState;

            Pair persistInfo = (Pair)viewState[0];
            foreach (Pair pair in (ArrayList)persistInfo.Second)
            {
                RestoreChildStructure(pair, this);
            }

            base.LoadViewState(viewState[1]);
        }

        protected override object SaveViewState()
        {

            if (HttpContext.Current == null)
                return null;

            object[] viewState = new object[2];
            viewState[0] = PersistChildStructure(this, "C");
            viewState[1] = base.SaveViewState();
            return viewState;
        }

        private void RestoreChildStructure(Pair persistInfo, Control parent)
        {
            Control control;

            string[] persistedString = persistInfo.First.ToString().Split(';');

            string[] typeName = persistedString[1].Split(':');
            switch (typeName[0])
            {

                case "C":
                    Type type = Type.GetType(typeName[1], true, true);
                    try
                    {
                        control = (Control)Activator.CreateInstance(type);
                    }
                    catch (Exception e)
                    {
                        throw new ArgumentException(String.Format("类型 '{0}' 不能恢复状态", type.

                  ToString()), e);
                    }
                    break;
                default:
                    throw new ArgumentException("无法识别的类型.不能恢复状态.");
            }

            control.ID = persistedString[2];

            switch (persistedString[0])
            {
                case "C":
                    parent.Controls.Add(control);
                    break;
            }

            foreach (Pair pair in (ArrayList)persistInfo.Second)
            {
                RestoreChildStructure(pair, control);
            }
        }

        private Pair PersistChildStructure(Control control, string controlCollectionName)
        {
            string typeName;
            ArrayList childPersistInfo = new ArrayList();

            if (control.ID == null)
            {
                if (ControlsWithoutIDs == HandleDynamicControls.ThrowException)
                    throw new NotSupportedException("你必须设置你的ID");
                else if (ControlsWithoutIDs == HandleDynamicControls.DontPersist)
                    return null;
            }

            typeName = "C:" + control.GetType().AssemblyQualifiedName;

            string persistedString = controlCollectionName + ";" + typeName + ";" + control.ID;

            if (!(control is UserControl) && !(control is CheckBoxList))
            {
                for (int counter = 0; counter < control.Controls.Count; counter++)
                {
                    Control child = control.Controls[counter];
                    Pair pair = PersistChildStructure(child, "C");
                    if (pair != null)
                        childPersistInfo.Add(pair);
                }
            }

            return new Pair(persistedString, childPersistInfo);
        }
        #endregion 视图状态管理

        重化控件样式#region 重化控件样式
        protected override void Render(System.Web.UI.HtmlTextWriter writer)
        {
            base.Render(writer);
        }
        //  
        #endregion 重化控件样式
    }

    public enum HandleDynamicControls
    {
        DontPersist,
        Persist,
        ThrowException
    }
}






<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default7.aspx.cs" Inherits="Default7" %>

 

 

<%@ Register Namespace="cn.co" TagPrefix="tt" %>

<!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>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:RadioButtonList ID="RadioButtonList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="RadioButtonList1_SelectedIndexChanged">
            <asp:ListItem>0</asp:ListItem>
            <asp:ListItem>1</asp:ListItem>
        </asp:RadioButtonList>
        
        <tt:DynamicControlsPanel  ControlsWithoutIDs=Persist runat=server ID="pan"></tt:DynamicControlsPanel>
  </div>

        

    </form>
</body>
</html>


using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Default7 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
 
    protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        switch (this.RadioButtonList1.SelectedValue)
        {    
      case "0": 
                Control con=Page.LoadControl("0.ascx");
            con.ID = "dd";
                this.pan.Controls.Clear();
                this.pan.Controls.Add(con);
                
                break;

          case "1": Control con1 = Page.LoadControl("1.ascx");
            con1.ID = "ddd";
                this.pan.Controls.Clear();
                this.pan.Controls.Add(con1);
                break;
        }
    }
}