asp.net初学习实现简单的增删改查功能
在学习中发现网页模板可以大大节约重复的页面代码，同时对于WebSite开发的程序在不同的页面直接调用已写好的代码既不方面，只是作为代码量不大的程序进行开发还是比较方便。
get和post的区别get是通过url传递表单值，post通过url看不到表单域的值；get传递的数据量是有限的，如果要传递大数据量不能用get，比如上传文章、传递密码或者<textarea>发表大段文章，post则没有这个限制；post会有浏览器提示重新提交表单的问题。也就是说get和post都是以不同的方式提交表单的信息，只是方式不一样，post是以头报文的形式传递，我们可以使用火狐的免费插件firebug或者免费的httpwatch（破解版的当然免费）,看到这些。
简单的说浏览器和服务器直接就是请求和回应，内部的具体细节可以看看博客园中的很多示例图，当然我们可以分析一下，就是浏览器通过DNS解析后向服务器发送请求，服务端侦听到客户端（浏览器）请求，开始分配相应套接字并建立连接，之后就是一方发送一方接收回应的过程，这里面存在一个长连接短连接的概念，具体还是查资料，这里就不多说了。
现在我们先来分析一下已经生成好的web程序，我们来反编译看下具体的执行过程。
我们只看其中关键的部分，也是我们一般程序中的主体部分，使用reflector
1 [CompilerGlobalScope] 2 public class default_aspx : _Default, IHttpHandler 3 { 4 // Fields 5 private static object __fileDependencies; 6 private static bool __initialized; 7 8 // Methods 9 [DebuggerNonUserCode] 10 public default_aspx(); 11 [DebuggerNonUserCode] 12 private HtmlHead __BuildControl__control2(); 13 [DebuggerNonUserCode] 14 private HtmlTitle __BuildControl__control3(); 15 [DebuggerNonUserCode] 16 private HtmlForm __BuildControlform1(); 17 [DebuggerNonUserCode] 18 private void __BuildControlTree(default_aspx __ctrl); 19 [DebuggerNonUserCode] 20 protected override void FrameworkInitialize(); 21 [DebuggerNonUserCode] 22 public override int GetTypeHashCode(); 23 [DebuggerNonUserCode] 24 public override void ProcessRequest(HttpContext context); 25 } 26 27 28 Expand Methods 29
它对应的源代码如下：
1 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> 2 3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 4 5 <html xmlns="http://www.w3.org/1999/xhtml"> 6 <head runat="server"> 7 <title>测试</title> 8 </head> 9 <body> 10 <form id="form1" runat="server"> 11 <div> 12 13 </div> 14 </form> 15 </body> 16 </html>
现在我们再来看关键的部分：
1 [DebuggerNonUserCode] 2 private void __BuildControlTree(default_aspx __ctrl) 3 { 4 this.InitializeCulture(); 5 IParserAccessor accessor = __ctrl; 6 accessor.AddParsedSubObject(new LiteralControl("\r\n\r\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\r\n\r\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\r\n")); 7 HtmlHead head = this.__BuildControl__control2(); 8 accessor.AddParsedSubObject(head); 9 accessor.AddParsedSubObject(new LiteralControl("\r\n<body>\r\n ")); 10 HtmlForm form = this.__BuildControlform1(); 11 accessor.AddParsedSubObject(form); 12 accessor.AddParsedSubObject(new LiteralControl("\r\n</body>\r\n</html>\r\n")); 13 }
从上面可以看出，.NET运行时将html创建成一个树对象，而后已以创建节点对象模型
1 [DebuggerNonUserCode] 2 private HtmlTitle __BuildControl__control3() 3 { 4 HtmlTitle title = new HtmlTitle(); 5 IParserAccessor accessor = title; 6 accessor.AddParsedSubObject(new LiteralControl("测试")); 7 return title; 8 }
这里我只是让大家能看到 <title>测试</title>的效果，具体的可以自己看看。
下面就写个小代码试下手感受下asp.net web开发，基本原理都差不多只是对于刚从Winform转过来的同学感觉上很繁琐,节约时间不多说了，直接上代码，代码简单就是为了自己熟悉测试的
1 <%@ WebHandler Language="C#" Class="List" %> 2 3 using System; 4 using System.Web; 5 using System.Data; 6 using System.Data.SqlClient; 7 8 public class List : IHttpHandler { 9 10 public void ProcessRequest (HttpContext context) { 11 context.Response.ContentType = "text/html"; 12 DataTable dt = SqlHelper.ExecuteDataTble(); 13 System.Text.StringBuilder sb = new System.Text.StringBuilder(); 14 foreach (DataRow dr in dt.Rows) 15 { 16 sb.AppendLine(" <tr>"); 17 sb.AppendLine("<td>" + dr["s_no"] + "</td>"); 18 sb.AppendLine("<td>" + dr["s_name"] + "</td>"); 19 sb.AppendLine("<td>" + dr["s_sex"] + "</td>"); 20 sb.AppendLine("<td>" + dr["s_birthday"] + "</td>"); 21 sb.AppendLine("<td>" + dr["s_avgrade"] + "</td>"); 22 sb.AppendLine("<td>" + dr["s_dept"] + "</td>"); 23 sb.AppendLine("<td><a href=del.ashx?id="+dr["s_no"]+">删除</td>"); 24 sb.AppendLine("<td><input type='checkbox' name='ckdel' value= '"+ dr["s_no"]+"'/>选择</td>"); 25 sb.AppendLine("<td><a href='UpdateRecord.ashx'>修改</td>"); 26 sb.AppendLine("<tr>"); 27 } 28 string content = System.IO.File.ReadAllText(context.Server.MapPath("model.htm")); 29 content = content.Replace("@replace", sb.ToString()).Replace("@title", "学生信息表"); 30 context.Response.Write(content); 31 } 32 33 public bool IsReusable { 34 get { 35 return false; 36 } 37 } 38 39 } 40 public class SqlHelper 41 { 42 public static System.Data.DataTable ExecuteDataTble() 43 { 44 using (SqlConnection con = new SqlConnection("Data Source=ROHELM-PC;Initial Catalog=T-SQL练手;Integrated Security=True")) 45 { 46 using (SqlCommand cmd = con.CreateCommand()) 47 { 48 cmd.CommandText = "select * from student"; 49 DataTable dt = new DataTable(); 50 SqlDataAdapter da = new SqlDataAdapter(cmd); 51 da.Fill(dt); 52 return dt; 53 } 54 } 55 } 56 }
下面这个其实保存的形式是什么无关紧要的，只要是文本形式就行。
model
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 <title></title> 5 <style type="text/css"> 6 table 7 { 8 background-color: Yellow; 9 border-color: Black; 10 border-spacing: 0; 11 border-style: dotted; 12 border-width: medium; 13 } 14 </style> 15 </head> 16 <body> 17 <fieldset title="增删改查测试"> 18 <form action="del.ashx" method="post"> 19 <table border="1"> 20 <thead> 21 <tr> 22 @title</tr> 23 </thead> 24 <tbody> 25 @replace 26 <tr> 27 <td colspan="6"> 28 <center> 29 <input type="submit" value="批量删除" /> 30 </center> 31 </td> 32 <td colspan="2"> 33 <a href="addRecord.htm">添加记录</a> 34 </td> 35 </tr> 36 </tbody> 37 </table> 38 </form> 39 </fieldset> 40 </body> 41 </html>
删除部分
del
1 <%@ WebHandler Language="C#" Class="del" %> 2 3 using System; 4 using System.Web; 5 using System.Data.SqlClient; 6 using System.IO; 7 public class del : IHttpHandler { 8 public void ProcessRequest (HttpContext context) { 9 string tooglePage = File.ReadAllText(context.Server.MapPath("jumpPage.htm")); 10 context.Response.ContentType = "text/html"; 11 //通过url传参数 12 string id = context.Request.QueryString["id"]; 13 string ids = context.Request.Form["ckdel"]; 14 if (!string.IsNullOrEmpty(id)) 15 { 16 SQLhelper.ExecuteNonQuery2("delete from student where s_no=@id", 17 new SqlParameter("@id", id) 18 ); 19 tooglePage = tooglePage.Replace("@targetPage", "List.ashx"); 20 context.Response.Write(tooglePage); 21 } 22 else if (!string.IsNullOrEmpty(ids)) 23 { 24 SQLhelper.ExecuteNonQuery2("delete from student where s_no in (" + ids + ")"); 25 tooglePage = tooglePage.Replace("@targetPage", "List.ashx"); 26 context.Response.Write(tooglePage); 27 } 28 else 29 { 30 31 context.Response.Write("删除不成功！"); 32 } 33 } 34 35 public bool IsReusable { 36 get { 37 return false; 38 } 39 } 40 41 } 42 public partial class SQLhelper 43 { 44 public static void ExecuteNonQuery2(string sql, params SqlParameter[] paramseter) 45 { 46 using (SqlConnection con = new SqlConnection("Data Source=ROHELM-PC;Initial Catalog=T-SQL练手;Integrated Security=True")) 47 { 48 con.Open(); 49 { 50 using (SqlCommand cmd = con.CreateCommand()) 51 { 52 cmd.CommandText = sql; 53 cmd.Parameters.AddRange(paramseter); 54 cmd.ExecuteNonQuery(); 55 } 56 } 57 } 58 } 59 }
添加部分
add
1 <%@ WebHandler Language="C#" Class="ADD"%> 2 3 using System; 4 using System.Web; 5 using System.Data.SqlClient; 6 7 public class ADD : IHttpHandler { 8 9 public void ProcessRequest (HttpContext context) { 10 context.Response.ContentType = "text/html"; 11 string s_name=context.Request.Form["Name"]; 12 string s_no = context.Request.Form["num"]; 13 SQLhelper.ExecuteNonQuery("insert into student(s_no,s_name)values(@number,@name)", 14 new SqlParameter("number", s_no), 15 new SqlParameter("name", s_name) 16 ); 17 context.Response.Redirect("List.ashx"); 18 } 19 20 public bool IsReusable { 21 get { 22 return false; 23 } 24 } 25 26 } 27 public partial class SQLhelper 28 { 29 public static void ExecuteNonQuery(string sql, params SqlParameter[] paramseter) 30 { 31 using (SqlConnection con = new SqlConnection("Data Source=ROHELM-PC;Initial Catalog=T-SQL练手;Integrated Security=True")) 32 { 33 con.Open(); 34 { 35 using (SqlCommand cmd = con.CreateCommand()) 36 { 37 cmd.CommandText = sql; 38 cmd.Parameters.AddRange(paramseter); 39 cmd.ExecuteNonQuery(); 40 } 41 } 42 } 43 } 44 }
使用数据库脚本：
SQL
1 USE [T-SQL练手] 2 GO 3 /****** Object: Table [dbo].[student] Script Date: 05/10/2012 00:05:40 ******/ 4 SET ANSI_NULLS ON 5 GO 6 SET QUOTED_IDENTIFIER ON 7 GO 8 SET ANSI_PADDING ON 9 GO 10 CREATE TABLE [dbo].[student]( 11 [s_no] [int] NOT NULL, 12 [s_name] [nvarchar](50) NOT NULL, 13 [s_sex] [char](2) NULL, 14 [s_birthday] [smalldatetime] NULL, 15 [s_speciality] [varchar](50) NULL, 16 [s_avgrade] [numeric](3, 1) NULL, 17 [s_dept] [varchar](50) NULL, 18 CONSTRAINT [PK__student__2F36BC5B7F60ED59] PRIMARY KEY CLUSTERED 19 ( 20 [s_no] ASC 21 )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 22 ) ON [PRIMARY] 23 GO 24 SET ANSI_PADDING OFF 25 GO 26 /****** Object: Default [DF__student__s_speci__03317E3D] Script Date: 05/10/2012 00:05:40 ******/ 27 ALTER TABLE [dbo].[student] ADD CONSTRAINT [DF__student__s_speci__03317E3D] DEFAULT ('计算机软件与理论') FOR [s_speciality] 28 GO 29 /****** Object: Default [DF__student__s_dept__0519C6AF] Script Date: 05/10/2012 00:05:40 ******/ 30 ALTER TABLE [dbo].[student] ADD CONSTRAINT [DF__student__s_dept__0519C6AF] DEFAULT ('计算机科学系') FOR [s_dept] 31 GO 32 /****** Object: Check [CK__student__s_avgra__0425A276] Script Date: 05/10/2012 00:05:40 ******/ 33 ALTER TABLE [dbo].[student] WITH CHECK ADD CONSTRAINT [CK__student__s_avgra__0425A276] CHECK (([s_avgrade]>=(0) AND [s_avgrade]<=(100))) 34 GO 35 ALTER TABLE [dbo].[student] CHECK CONSTRAINT [CK__student__s_avgra__0425A276] 36 GO 37 /****** Object: Check [CK__student__s_birth__023D5A04] Script Date: 05/10/2012 00:05:40 ******/ 38 ALTER TABLE [dbo].[student] WITH CHECK ADD CONSTRAINT [CK__student__s_birth__023D5A04] CHECK (([s_birthday]>='1970-1-1' AND [s_birthday]<='2000-1-1')) 39 GO 40 ALTER TABLE [dbo].[student] CHECK CONSTRAINT [CK__student__s_birth__023D5A04] 41 GO 42 /****** Object: Check [CK__student__s_sex__014935CB] Script Date: 05/10/2012 00:05:40 ******/ 43 ALTER TABLE [dbo].[student] WITH CHECK ADD CONSTRAINT [CK__student__s_sex__014935CB] CHECK (([s_sex]='男' OR [s_sex]='女')) 44 GO 45 ALTER TABLE [dbo].[student] CHECK CONSTRAINT [CK__student__s_sex__014935CB] 46 GO
运行效果：
其他操作显示区域没有调整好，且受到上传图片的限制未演示。
