ASP.NET简单的等级星自定义控件

在ASP.NET WebForm 中常常需要我们自定义控件来实现特定的功能，比如分页控件等等。相比用户控件（User Control），它在使用更加灵活，完成的工作也就更强大。
下面是我写的一个小的Demo，来演示如何自定义控件。

先看VS解决方案截图：

 

 

自定义控件的核心代码如下：

 

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using System; using System.Collections.Generic; using System.Linq; using System.Text;   using System.ComponentModel; using System.Web; using System.Web.UI; using System.Web.UI.WebControls;   [assembly: WebResource("CustomerConLibrary.Image.stars.gif", "image/gif")] namespace CustomerConLibrary {       [ToolboxData("<{0}:Star runat=\"server\"></{0}:Star>")]     public class Star : WebControl     {         [Category("NewAttribute")]         [Description("分数")]         [Browsable(true)]         [DefaultValue(0)]         public int Score         {             get             {                 object obj = ViewState["Score"];                 return obj == null ? 0 : Convert.ToInt32(obj);             }             set             {                 ViewState["Score"] = value;             }         }           [Category("NewAttribute")]         [Description("文字")]         [Browsable(true)]         [DefaultValue("")]         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)         {             string starPath = Page.ClientScript.GetWebResourceUrl(this.GetType(), "CustomerConLibrary.Image.stars.gif");               Panel panBg = new Panel();             panBg.Style.Add(HtmlTextWriterStyle.Width, "80px");             panBg.Style.Add(HtmlTextWriterStyle.Height, "16px");             panBg.Style.Add(HtmlTextWriterStyle.TextAlign, "left");             panBg.Style.Add(HtmlTextWriterStyle.Overflow, "hidden");             panBg.Style.Add(HtmlTextWriterStyle.BackgroundImage, starPath);             panBg.Style.Add("background-position", "0px -32px");             panBg.Style.Add("background-repeat", "repeat-x");               cell.Controls.Add(panBg);               Panel panCur = new Panel();             string width = Score * 16 + "px";             panCur.Style.Add(HtmlTextWriterStyle.Width, width);             panCur.Style.Add(HtmlTextWriterStyle.Height, "16px");             panCur.Style.Add(HtmlTextWriterStyle.BackgroundImage, starPath);             panCur.Style.Add("background-position", "0px 0px");             panCur.Style.Add("background-repeat", "repeat-x");               panBg.Controls.Add(panCur);         }           protected override void Render(HtmlTextWriter writer)         {             PrepareControlForReader();               base.Render(writer);         }           private void PrepareControlForReader()         {             if (this.Controls.Count < 1)                 return;               Table table = (Table)this.Controls[0];               table.CellSpacing = 0;             table.CellPadding = 0;         }     } }

 

这里需要注意的是，如果有图片、JS文件、CSS文件等等，需要打包成DLL的话，右键该文件的属性：

 

 

 

使用就很简单了，首页引用DLL，然后在页面中注册，使用就可以了：

 

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<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>   <%@ Register TagPrefix="cc" Assembly="CustomerConLibrary" Namespace="CustomerConLibrary" %>   <!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></title> </head> <body>     <form id="form1" runat="server">     <div>                   <cc:Star ID="star1" runat="server" Comment="WindowsXP" Score="3" />               </div>     </form> </body> </html>

 

效果图如下：

 

谢谢浏览！