asp.net自定义控件

using System;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace ControlLibrary
{
public class PostStar : WebControl, IPostBackEventHandler, INamingContainer
{
private event EventHandler<StarEventArgs> _postScore;

public event EventHandler<StarEventArgs> PostScore
{
add
{
_postScore += value;
}
remove
{
_postScore -= value;
}
}

private void OnPostScore(object sender, StarEventArgs e)
{
if (_postScore != null)
_postScore(sender, e);

TableCell cell = ((Table)this.Controls[0]).Rows[0].Cells[1];
Panel panCur = (Panel)cell.Controls[0].Controls[1];
panCur.Style.Add("width", e.Score * 16 + "px");
Panel panChange = (Panel)panCur.Controls[0];
panChange.Style.Add("display", "none");
HtmlGenericControl ul = (HtmlGenericControl)cell.Controls[0].Controls[0];
ul.Style.Add("display", "none");

}

[DefaultValue(0)]
public int Score
{
get
{
object obj = ViewState["Score"];
return obj == null ? 0 : Convert.ToInt32(obj);
}
internal set
{
ViewState["Score"] = value;
}
}

public string Comment
{
get
{
object obj = ViewState["Comment"];
return obj == null ? string.Empty : Convert.ToString(obj);
}
set
{
ViewState["Comment"] = value;
}
}

protected override void CreateChildControls()
{
base.CreateChildControls();

CreateControlHierarchy();
}

protected virtual void CreateControlHierarchy()
{
Table table = new Table();
TableRow row = new TableRow();
table.Rows.Add(row);
TableCell comment = new TableCell();
CreateComment(comment);
row.Cells.Add(comment);

TableCell stars = new TableCell();

CreateStars(stars);

row.Cells.Add(stars);

this.Controls.Add(table);
}

/// <summary>
/// 向单元格中创建注释标签
/// </summary>
/// <param name="cell">单元格对象</param>
private void CreateComment(TableCell cell)
{
cell.Text = Comment;
}

/// <summary>
/// 向单元格中创建星形图案
/// </summary>
/// <param name="cell"></param>
private void CreateStars(TableCell cell)
{
RegisterCSS();

string starPath = Page.ClientScript.GetWebResourceUrl(this.GetType(), "ControlLibrary.Image.stars.gif");

Panel panBg = CreateBackPanel(starPath);

cell.Controls.Add(panBg);

Panel panCur = CreateCurrentPanel(starPath);
Panel panChange = CreateChangePanel(starPath);
HtmlGenericControl ul = CreateList();

panBg.Controls.Add(ul);

panBg.Controls.Add(panCur);
panCur.Controls.Add(panChange);
}

private void RegisterCSS()
{
string css = Page.ClientScript.GetWebResourceUrl(this.GetType(), "ControlLibrary.CSS.star.css");

HtmlLink link = new HtmlLink();
link.Href = css;
link.Attributes.Add("rel", "stylesheet");
link.Attributes.Add("type", "text/css");

Page.Header.Controls.Add(link);
}

private Panel CreateBackPanel(string starPath)
{
Panel panBg = new Panel();

panBg.ID = "divBg";
panBg.Style.Add(HtmlTextWriterStyle.BackgroundImage, starPath);

panBg.CssClass = "stars";

return panBg;
}

private Panel CreateCurrentPanel(string starPath)
{
Panel panCur = new Panel();

panCur.ID = "divCur";
panCur.Style.Add(HtmlTextWriterStyle.BackgroundImage, starPath);
panCur.CssClass = "current";

return panCur;
}

private Panel CreateChangePanel(string starPath)
{
Panel panChange = new Panel();

panChange.ID = "divChange";
panChange.Style.Add(HtmlTextWriterStyle.BackgroundImage, starPath);

panChange.CssClass = "change";

return panChange;
}

private HtmlGenericControl CreateList()
{
HtmlGenericControl ul = new HtmlGenericControl("ul");

ul.ID = "ulist";

ul.Attributes.Add("class", "ulist");

for (int i = 0; i < 5; i++)
{
HtmlGenericControl li = new HtmlGenericControl("li");
li.Attributes.Add("value", (i + 1).ToString());

ul.Controls.Add(li);
}

return ul;
}

public void RaisePostBackEvent(string args)
{
if (!string.IsNullOrEmpty(args))
{
EnsureChildControls();

int score = Convert.ToInt32(args);

StarEventArgs e = new StarEventArgs();
e.Score = score;

OnPostScore(this, e);
}
}

protected override void Render(HtmlTextWriter writer)
{
PrepareControlForRender();

base.Render(writer);
}

private void PrepareControlForRender()
{
if (this.Controls.Count < 1)
return;

Table table = (Table)this.Controls[0];

table.CellSpacing = 0;
table.CellPadding = 0;

TableCell cell = table.Rows[0].Cells[1];
Panel panCur = (Panel)cell.Controls[0].Controls[1];
Panel panChange = (Panel)panCur.Controls[0];
HtmlGenericControl ul = (HtmlGenericControl)cell.Controls[0].Controls[0];

for (int i = 0; i < ul.Controls.Count; i++)
{
HtmlGenericControl li = (HtmlGenericControl)ul.Controls[i];
li.Attributes.Add("onmouseover", "document.getElementById('" + panChange.ClientID + "').style.width='" + 16 * (i + 1) + "px';");
li.Attributes.Add("onmouseout", "document.getElementById('" + panChange.ClientID + "').style.width='0px';");
li.Attributes.Add("onclick", Page.ClientScript.GetPostBackClientHyperlink(this, (i + 1).ToString()));
}
}
}

public class StarEventArgs : EventArgs
{
public int Score
{
get;
set;
}
}
}

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<cc:PostStar ID="star" runat="server" Comment="Windows XP" OnPostScore="star_PostScore" />
<br />
<cc:PostStar ID="star2" runat="server" Comment="VISTA" OnPostScore="star_PostScore" />
</div>
</form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

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

}

protected void star_PostScore(object sender, ControlLibrary.StarEventArgs e)
{
Response.Write(e.Score);
}
}