自定义控件源码（转贴）

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.ComponentModel.Design.Serialization;
using System.Collections;
using System.Diagnostics;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace abcde
{
    /**//// <summary>
    /// 表示TemplatedList的项
    /// </summary>
    public class TemplatedListItem : TableRow, INamingContainer
    {
        private int itemIndex;
        private ListItemType itemType;
        private object dataItem;

        public TemplatedListItem(int itemIndex, ListItemType itemType)
        {
            this.itemIndex = itemIndex;
            this.itemType = itemType;

            Cells.Add(new TableCell());
        }

        /**//// <summary>
        /// 获取或设置TemplatedListItem对象关联的数据项。 
        /// </summary>
        public virtual object DataItem
        {
            get
            {
                return dataItem;
            }
            set
            {
                dataItem = value;
            }
        }

        /**//// <summary>
        /// 项索引
        /// </summary>
        public virtual int ItemIndex
        {
            get
            {
                return itemIndex;
            }
        }

        /**//// <summary>
        /// 项类型
        /// </summary>
        public virtual ListItemType ItemType
        {
            get
            {
                return itemType;
            }
        }

        protected override bool OnBubbleEvent(object source, EventArgs e)
        {
            if (e is CommandEventArgs)
            {
                // Add the information about Item to CommandEvent.

                TemplatedListCommandEventArgs args =
                    new TemplatedListCommandEventArgs(this, source, (CommandEventArgs)e);

                RaiseBubbleEvent(this, args);
                return true;
            }
            return false;
        }

        /**//// <summary>
        /// 设置项类型
        /// </summary>
        /// <param name="itemType"></param>
        internal void SetItemType(ListItemType itemType)
        {
            this.itemType = itemType;
        }
    }
}

    using System;
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using System.ComponentModel.Design.Serialization;
    using System.Collections;
    using System.Diagnostics;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using abcde;
namespace abcde
{

    [
    DefaultEvent("SelectedIndexChanged"),
    DefaultProperty("DataSource")
    ]
    public class TemplatedList : WebControl, INamingContainer
    {


        private static readonly object EventSelectedIndexChanged = new object();
        private static readonly object EventItemCreated = new object();
        private static readonly object EventItemDataBound = new object();
        private static readonly object EventItemCommand = new object();
        

 
        private IEnumerable dataSource;
        private TableItemStyle itemStyle;
        private TableItemStyle alternatingItemStyle;
        private TableItemStyle selectedItemStyle;
        private ITemplate itemTemplate;
        

      

        [
        Category("Style"),
        Description("交替项样式"),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
        NotifyParentProperty(true),
        PersistenceMode(PersistenceMode.InnerProperty),
        ]
        public virtual TableItemStyle AlternatingItemStyle
        {
            get
            {
                if (alternatingItemStyle == null)
                {
                    alternatingItemStyle = new TableItemStyle();
                    if (IsTrackingViewState)
                        ((IStateManager)alternatingItemStyle).TrackViewState();
                }
                return alternatingItemStyle;
            }
        }


        [
        Category("Style"),
        Description("一般项样式"),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
        NotifyParentProperty(true),
        PersistenceMode(PersistenceMode.InnerProperty),
        ]
        public virtual TableItemStyle ItemStyle
        {
            get
            {
                if (itemStyle == null)
                {
                    itemStyle = new TableItemStyle();
                    if (IsTrackingViewState)
                        ((IStateManager)itemStyle).TrackViewState();
                }
                return itemStyle;
            }
        }

        [
         Category("Style"),
         Description("选中项样式"),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
         NotifyParentProperty(true),
         PersistenceMode(PersistenceMode.InnerProperty),
         ]
        public virtual TableItemStyle SelectedItemStyle
        {
            get
            {
                if (selectedItemStyle == null)
                {
                    selectedItemStyle = new TableItemStyle();
                    if (IsTrackingViewState)
                        ((IStateManager)selectedItemStyle).TrackViewState();
                }
                return selectedItemStyle;
            }
        }



        [
        Bindable(true),
        Category("Appearance"),
        DefaultValue(-1),
        Description("The cell padding of the rendered table.")
        ]
        public virtual int CellPadding
        {
            get
            {
                if (ControlStyleCreated == false)
                {
                    return -1;
                }
                return ((TableStyle)ControlStyle).CellPadding;
            }
            set
            {
                ((TableStyle)ControlStyle).CellPadding = value;
            }
        }

        [
        Bindable(true),
        Category("Appearance"),
        DefaultValue(0),
        Description("The cell spacing of the rendered table.")
        ]
        public virtual int CellSpacing
        {
            get
            {
                if (ControlStyleCreated == false)
                {
                    return 0;
                }
                return ((TableStyle)ControlStyle).CellSpacing;
            }
            set
            {
                ((TableStyle)ControlStyle).CellSpacing = value;
            }
        }



        [
        Bindable(true),
        Category("Appearance"),
        DefaultValue(GridLines.None),
        Description("The grid lines to be shown in the rendered table.")
        ]
        public virtual GridLines GridLines
        {
            get
            {
                if (ControlStyleCreated == false)
                {
                    return GridLines.None;
                }
                return ((TableStyle)ControlStyle).GridLines;
            }
            set
            {
                ((TableStyle)ControlStyle).GridLines = value;
            }
        }

        [
        Bindable(true),
        Category("Data"),
        DefaultValue(null),
        Description("数据源"),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
        public IEnumerable DataSource
        {
            get
            {
                return dataSource;
            }
            set
            {
                dataSource = value;
            }
        }


        [
        Browsable(false),
        DefaultValue(null),
        Description("项模板"),
        PersistenceMode(PersistenceMode.InnerProperty),
        TemplateContainer(typeof(TemplatedListItem))
        ]
        public virtual ITemplate ItemTemplate
        {
            get
            {
                return itemTemplate;
            }
            set
            {
                itemTemplate = value;
            }
        }


        [
        Bindable(true),
        DefaultValue(-1),
        Description("选中项索引,默认为-1")
        ]
        public virtual int SelectedIndex
        {
            get
            {
                object o = ViewState["SelectedIndex"];
                if (o != null)
                    return (int)o;
                return -1;
            }
            set
            {
                if (value < -1)
                {
                    throw new ArgumentOutOfRangeException();
                }
                //获取上次选中项
                int oldSelectedIndex = SelectedIndex;
                ViewState["SelectedIndex"] = value;

                if (HasControls())
                {
                    Table table = (Table)Controls[0];
                    TemplatedListItem item;

                    //第一次选中项不执行
                    if ((oldSelectedIndex != -1) && (table.Rows.Count > oldSelectedIndex))
                    {
                        item = (TemplatedListItem)table.Rows[oldSelectedIndex];
                        //判断项类型,为了将选中项还原为数据项
                        if (item.ItemType != ListItemType.EditItem)
                        {
                            ListItemType itemType = ListItemType.Item;
                            if (oldSelectedIndex % 2 != 0)
                                itemType = ListItemType.AlternatingItem;
                            item.SetItemType(itemType);
                        }
                    }
                    //第一次执行此项,并一直执行
                    if ((value != -1) && (table.Rows.Count > value))
                    {
                        item = (TemplatedListItem)table.Rows[value];
                        item.SetItemType(ListItemType.SelectedItem);
                    }
                }
            }
        }


        

        
        protected virtual void OnItemCommand(TemplatedListCommandEventArgs e)
        {
            TemplatedListCommandEventHandler onItemCommandHandler = (TemplatedListCommandEventHandler)Events[EventItemCommand];
            if (onItemCommandHandler != null) onItemCommandHandler(this, e);
        }

        protected virtual void OnItemCreated(TemplatedListItemEventArgs e)
        {
            TemplatedListItemEventHandler onItemCreatedHandler = (TemplatedListItemEventHandler)Events[EventItemCreated];
            if (onItemCreatedHandler != null) onItemCreatedHandler(this, e);
        }

        protected virtual void OnItemDataBound(TemplatedListItemEventArgs e)
        {
            TemplatedListItemEventHandler onItemDataBoundHandler = (TemplatedListItemEventHandler)Events[EventItemDataBound];
            if (onItemDataBoundHandler != null) onItemDataBoundHandler(this, e);
        }

        protected virtual void OnSelectedIndexChanged(EventArgs e)
        {
            EventHandler handler = (EventHandler)Events[EventSelectedIndexChanged];
            if (handler != null) handler(this, e);
        }

        [
        Category("Action"),
        Description("Raised when a CommandEvent occurs within an item.")
        ]
        public event TemplatedListCommandEventHandler ItemCommand
        {
            add
            {
                Events.AddHandler(EventItemCommand, value);
            }
            remove
            {
                Events.RemoveHandler(EventItemCommand, value);
            }
        }

        [
        Category("Behavior"),
        Description("Raised when an item is created and is ready for customization.")
        ]
        public event TemplatedListItemEventHandler ItemCreated
        {
            add
            {
                Events.AddHandler(EventItemCreated, value);
            }
            remove
            {
                Events.RemoveHandler(EventItemCreated, value);
            }
        }

        [
        Category("Behavior"),
        Description("Raised when an item is data-bound.")
        ]
        public event TemplatedListItemEventHandler ItemDataBound
        {
            add
            {
                Events.AddHandler(EventItemDataBound, value);
            }
            remove
            {
                Events.RemoveHandler(EventItemDataBound, value);
            }
        }

        [
        Category("Action"),
        Description("Raised when the SelectedIndex property has changed.")
        ]
        public event EventHandler SelectedIndexChanged
        {
            add
            {
                Events.AddHandler(EventSelectedIndexChanged, value);
            }
            remove
            {
                Events.RemoveHandler(EventSelectedIndexChanged, value);
            }
        }
        


        /**//// <summary>
        /// 重写创建子控件
        /// </summary>
        protected override void CreateChildControls()
        {
            Controls.Clear();

            if (ViewState["ItemCount"] != null)
            {
                //创建一个带或不带指定数据源的控件层次结构
                CreateControlHierarchy(false);
            }
        }

        /**//// <summary>
        /// 重写创建控件样式
        /// </summary>
        /// <returns></returns>
        protected override Style CreateControlStyle()
        {


            TableStyle style = new TableStyle(ViewState);
            style.CellSpacing = 0;

            return style;
        }

        /**//// <summary>
        /// 创建一个带或不带指定数据源的控件层次结构
        /// </summary>
        /// <param name="useDataSource">指示是否要使用指定的数据源</param>
        //注意：当第二次执行数据绑定时，会执行两遍
        private void CreateControlHierarchy(bool useDataSource)
        {
            IEnumerable dataSource = null;
            int count = -1;


            if (useDataSource == false)
            {
                // ViewState must have a non-null value for ItemCount because this is checked 
                //  by CreateChildControls.
                count = (int)ViewState["ItemCount"];
                if (count != -1)
                {
                    dataSource = new DummyDataSource(count);
                }
            }
            else
            {
                dataSource = this.dataSource;
            }

            //根据项类型开始创建子控件
            if (dataSource != null)
            {
                Table table = new Table();
                Controls.Add(table);

                //选中项索引
                int selectedItemIndex = SelectedIndex;
                //项索引
                int index = 0;
                //项数量
                count = 0;
                foreach (object dataItem in dataSource)
                {

                    ListItemType itemType = ListItemType.Item;
                    if (index == selectedItemIndex)
                    {

                        itemType = ListItemType.SelectedItem;
                    }
                    else if (index % 2 != 0)
                    {
                        itemType = ListItemType.AlternatingItem;
                    }

                    //根据不同项索引创建样式
                    CreateItem(table, index, itemType, useDataSource, dataItem);
                    count++;
                    index++;
                }
            }
            //执行绑定时执行时执行
            if (useDataSource)
            {
                //保存项数量
                ViewState["ItemCount"] = ((dataSource != null) ? count : -1);
            }
        }


        //创建项
        private TemplatedListItem CreateItem(Table table, int itemIndex, ListItemType itemType, bool dataBind, object dataItem)
        {
            TemplatedListItem item = new TemplatedListItem(itemIndex, itemType);
            TemplatedListItemEventArgs e = new TemplatedListItemEventArgs(item);

            if (itemTemplate != null)
            {
                itemTemplate.InstantiateIn(item.Cells[0]);
            }
            if (dataBind)
            {
                item.DataItem = dataItem;
            }
            //注意事件触发顺序
            OnItemCreated(e);
            table.Rows.Add(item);

            if (dataBind)
            {
                item.DataBind();
                OnItemDataBound(e);

                item.DataItem = null;
            }

            return item;
        }

        //控件执行绑定时执行
        public override void DataBind()
        {

            base.OnDataBinding(EventArgs.Empty);

            //移除控件
            Controls.Clear();
            //清除视图状态信息
            ClearChildViewState();

            //创建一个带或不带指定数据源的控件层次结构
            CreateControlHierarchy(true);
            ChildControlsCreated = true;

            TrackViewState();
        }

        //事件冒泡
        protected override bool OnBubbleEvent(object source, EventArgs e)
        {
            // Handle events raised by children by overriding OnBubbleEvent.

            bool handled = false;

            if (e is TemplatedListCommandEventArgs)
            {
                TemplatedListCommandEventArgs ce = (TemplatedListCommandEventArgs)e;

                OnItemCommand(ce);
                handled = true;
                //预定义触发Selected事件
                if (String.Compare(ce.CommandName, "Select", true) == 0)
                {
                    SelectedIndex = ce.Item.ItemIndex;
                    OnSelectedIndexChanged(EventArgs.Empty);
                }
            }

            return handled;
        }

        //为不同类型项加载样式
        private void PrepareControlHierarchy()
        {
            if (HasControls() == false)
            {
                return;
            }

            Debug.Assert(Controls[0] is Table);
            Table table = (Table)Controls[0];

            table.CopyBaseAttributes(this);
            if (ControlStyleCreated)
            {
                table.ApplyStyle(ControlStyle);
            }

            // The composite alternating item style; do just one
            // merge style on the actual item.
            Style altItemStyle = null;
            if (alternatingItemStyle != null)
            {
                altItemStyle = new TableItemStyle();
                altItemStyle.CopyFrom(itemStyle);
                altItemStyle.CopyFrom(alternatingItemStyle);
            }
            else
            {
                altItemStyle = itemStyle;
            }

            int rowCount = table.Rows.Count;
            for (int i = 0; i < rowCount; i++)
            {
                TemplatedListItem item = (TemplatedListItem)table.Rows[i];
                Style compositeStyle = null;
                //根据不同项加载不同样式
                switch (item.ItemType)
                {
                    case ListItemType.Item:
                        compositeStyle = itemStyle;
                        break;

                    case ListItemType.AlternatingItem:
                        compositeStyle = altItemStyle;
                        break;

                    case ListItemType.SelectedItem:
                        {
                            compositeStyle = new TableItemStyle();

                            if (item.ItemIndex % 2 != 0)
                                compositeStyle.CopyFrom(altItemStyle);
                            else
                                compositeStyle.CopyFrom(itemStyle);
                            compositeStyle.CopyFrom(selectedItemStyle);
                        }
                        break;
                }

                if (compositeStyle != null)
                {
                    item.MergeStyle(compositeStyle);
                }
            }
        }

        //控件呈现
        protected override void Render(HtmlTextWriter writer)
        {
            // Apply styles to the control hierarchy
            // and then render it out.

            // Apply styles during render phase, so the user can change styles
            // after calling DataBind without the property changes ending
            // up in view state.
            PrepareControlHierarchy();

            RenderContents(writer);
        }

 

        protected override void LoadViewState(object savedState)
        {
            // Customize state management to handle saving state of contained objects.

            if (savedState != null)
            {
                object[] myState = (object[])savedState;

                if (myState[0] != null)
                    base.LoadViewState(myState[0]);
                if (myState[1] != null)
                    ((IStateManager)ItemStyle).LoadViewState(myState[1]);
                if (myState[2] != null)
                    ((IStateManager)SelectedItemStyle).LoadViewState(myState[2]);
                if (myState[3] != null)
                    ((IStateManager)AlternatingItemStyle).LoadViewState(myState[3]);
            }
        }

        protected override object SaveViewState()
        {
            // Customized state management to handle saving state of contained objects such as styles.

            object baseState = base.SaveViewState();
            object itemStyleState = (itemStyle != null) ? ((IStateManager)itemStyle).SaveViewState() : null;
            object selectedItemStyleState = (selectedItemStyle != null) ? ((IStateManager)selectedItemStyle).SaveViewState() : null;
            object alternatingItemStyleState = (alternatingItemStyle != null) ? ((IStateManager)alternatingItemStyle).SaveViewState() : null;

            object[] myState = new object[4];
            myState[0] = baseState;
            myState[1] = itemStyleState;
            myState[2] = selectedItemStyleState;
            myState[3] = alternatingItemStyleState;

            return myState;
        }

        protected override void TrackViewState()
        {
            // Customized state management to handle saving state of contained objects such as styles.

            base.TrackViewState();

            if (itemStyle != null)
                ((IStateManager)itemStyle).TrackViewState();
            if (selectedItemStyle != null)
                ((IStateManager)selectedItemStyle).TrackViewState();
            if (alternatingItemStyle != null)
                ((IStateManager)alternatingItemStyle).TrackViewState();
        } 
    }

    

    public sealed class TemplatedListCommandEventArgs : CommandEventArgs
    {

        private TemplatedListItem item;
        private object commandSource;

        public TemplatedListCommandEventArgs(TemplatedListItem item, object commandSource, CommandEventArgs originalArgs)
            :
            base(originalArgs)
        {
            this.item = item;
            this.commandSource = commandSource;
        }

        public TemplatedListItem Item
        {
            get
            {
                return item;
            }
        }

        public object CommandSource
        {
            get
            {
                return commandSource;
            }
        }
    }

    public delegate void TemplatedListCommandEventHandler(object source, TemplatedListCommandEventArgs e);

    public sealed class TemplatedListItemEventArgs : EventArgs
    {

        private TemplatedListItem item;

        public TemplatedListItemEventArgs(TemplatedListItem item)
        {
            this.item = item;
        }

        public TemplatedListItem Item
        {
            get
            {
                return item;
            }
        }
    }

    public delegate void TemplatedListItemEventHandler(object sender, TemplatedListItemEventArgs e);

    
}

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default10.aspx.cs" Inherits="Default10" %>
<%@ Register  Namespace="abcde" TagPrefix="aspDemo" %>
<!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>
    <aspDemo:TemplatedList runat="server" id="myList1"
    Font-Name="Verdana" Font-Size="16pt"
    BorderColor="Gray" BorderWidth="1px"
    CellSpacing="0" CellPadding="2" GridLines="Both"
    onItemCreated="MyList_ItemCreated"
    onSelectedIndexChanged="MyList_SelectedIndexChanged">
  <ItemStyle ForeColor="Black" BackColor="#EEEEEE"/>
  <AlternatingItemStyle BackColor="#DCDCDC"/>
  <SelectedItemStyle ForeColor="White" BackColor="#000084"/>
 
  <ItemTemplate>
    <asp:Button runat="server" id="selectButton" CommandName="Select"
        Text="Select" ForeColor="Blue"></asp:Button>&nbsp;&nbsp;
    <asp:Label ID="Label1" runat="server" Text='<%# Container.DataItem %>'></asp:Label>
  </ItemTemplate>
</aspDemo:TemplatedList>
<hr>
<asp:Label runat="server" id="infoLabel"></asp:Label>
<hr>
    </div>
    </form>
</body>
</html>

<script runat="server">

private int selectedIndex = -1;

private void LoadData() {
    ArrayList data = new ArrayList();

    for (int i = 0; i < 10; i++) {
        data.Add("Item " + i);
    }
    
    myList1.DataSource = data;
    myList1.DataBind();
    
}

protected override void OnLoad(EventArgs e) {
    base.OnLoad(e);
    if (!IsPostBack) {
        LoadData();
        //myList1.SelectedIndex = 4;
    }
}

    
protected void MyList_ItemCreated(object sender, TemplatedListItemEventArgs e) {
    if (e.Item.ItemType == ListItemType.SelectedItem) {
        selectedIndex = e.Item.ItemIndex;

        Button selectButton = (Button)e.Item.FindControl("selectButton");
        selectButton.Enabled = false;
    }
}

protected void MyList_SelectedIndexChanged(object sender, EventArgs e) {
    if (selectedIndex != -1) {
        Control item = myList1.Controls[0].Controls[selectedIndex];
        Button selectButton = (Button)item.FindControl("selectButton");
        selectButton.Enabled = true;
    }

    selectedIndex = myList1.SelectedIndex;
    infoLabel.Text = "SelectedIndex: " + selectedIndex;

    if (selectedIndex != -1) {
        Control item = myList1.Controls[0].Controls[selectedIndex];
        Button selectButton = (Button)item.FindControl("selectButton");
        selectButton.Enabled = false;
    }
   
}
</script>

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.ComponentModel.Design.Serialization;
using System.Collections;
using System.Diagnostics;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace abcde
{
    internal sealed class DummyDataSource : ICollection
    {

        private int dataItemCount;

        public DummyDataSource(int dataItemCount)
        {
            this.dataItemCount = dataItemCount;
        }

        public int Count
        {
            get
            {
                return dataItemCount;
            }
        }

        public bool IsReadOnly
        {
            get
            {
                return false;
            }
        }

        public bool IsSynchronized
        {
            get
            {
                return false;
            }
        }

        public object SyncRoot
        {
            get
            {
                return this;
            }
        }

        public void CopyTo(Array array, int index)
        {
            for (IEnumerator e = this.GetEnumerator(); e.MoveNext(); )
                array.SetValue(e.Current, index++);
        }

        public IEnumerator GetEnumerator()
        {
            return new DummyDataSourceEnumerator(dataItemCount);
        }

        private class DummyDataSourceEnumerator : IEnumerator
        {

            private int count;
            private int index;

            public DummyDataSourceEnumerator(int count)
            {
                this.count = count;
                this.index = -1;
            }

            public object Current
            {
                get
                {
                    return null;
                }
            }

            public bool MoveNext()
            {
                index++;
                return index < count;
            }

            public void Reset()
            {
                this.index = -1;
            }
        }
    }
}