说明（2017-10-6 11:21:58）：
1. 十一放假在家也没写几行代码，本来还想着利用假期把asp.net看完，结果天天喝酒睡觉，回去的票也没买到，惨。。
2. 断断续续的把用户信息的页面写完了，用了三层的方法，之前一直也没记下来，忘了的时候，每次都是从视频里找，这次好歹也要写下来，方便以后抄。
3. 希望十月份能把asp.net学完，然后看传说中的MVC。
代码：
1. 结构图
2. 建立三个类库，一个空web应用程序。DAL引Model，BLL引DAL和Model，WebApp引Model和BLL，反正各种引用。
3. Model里建一个UserInfo类，里面是用户字段和属性。
UserInfo.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 ?6 namespace JJW.Model 7 { 8 ????public class UserInfo 9 ????{10 ????????public int ID { get; set; }11 ????????public string UserName { get; set; }12 ????????public string PassWord { get; set; }13 ????}14 }4. DAL里有两个类，一个SqlHelper类，里面有两个方法GetTable和ExecuteNonQuery，GetTable负责查询，ExecuteNonQuery负责增删改。另一个UserInfoDal类，里面调用SqlHelper类，细化了增删改查的方法。三层里最重要的就是这个DAL层了。
SqlHelper.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.Configuration; 6 using System.Data; 7 using System.Data.SqlClient; 8 ?9 namespace JJW.DAL10 {11 ????public static class SqlHelper12 ????{13 ????????private static readonly string conStr = ConfigurationManager.ConnectionStrings["conStr"].ConnectionString;14 ????????public static DataTable GetTable(string sql, CommandType type, params SqlParameter[] ps)15 ????????{16 ????????????using (SqlConnection con = new SqlConnection(conStr))17 ????????????{18 ????????????????using (SqlDataAdapter sda = new SqlDataAdapter(sql, con))19 ????????????????{20 ????????????????????DataTable dt = new DataTable();21 ????????????????????sda.SelectCommand.CommandType = type;22 ????????????????????if (ps != null)23 ????????????????????{24 ????????????????????????sda.SelectCommand.Parameters.AddRange(ps);25 ????????????????????}26 ????????????????????sda.Fill(dt);27 ????????????????????return dt;28 ????????????????}29 ????????????}30 ????????}31 32 ????????public static int ExecuteNonQuery(string sql, CommandType type, params SqlParameter[] ps)33 ????????{34 ????????????using (SqlConnection con = new SqlConnection(conStr))35 ????????????{36 ????????????????using (SqlCommand cmd = new SqlCommand(sql, con))37 ????????????????{38 ????????????????????cmd.CommandType = type;39 ????????????????????if (ps != null)40 ????????????????????{41 ????????????????????????cmd.Parameters.AddRange(ps);42 ????????????????????}43 ????????????????????con.Open();44 ????????????????????return cmd.ExecuteNonQuery();45 ????????????????}46 ????????????}47 ????????}48 ????}49 }UserInfoDal.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using JJW.Model; 6 using System.Data; 7 using System.Data.SqlClient; 8 ?9 namespace JJW.DAL10 {11 ????public class UserInfoDal12 ????{13 ????????/// <summary>14 ????????/// 返回列表15 ????????/// </summary>16 ????????/// <returns></returns>17 ????????public List<UserInfo> GetEntity()18 ????????{19 ????????????string sql = "SELECT * FROM userInfo";20 ????????????DataTable dt = SqlHelper.GetTable(sql, CommandType.Text);21 ????????????List<UserInfo> list = new List<UserInfo>();22 ????????????if (dt.Rows.Count > 0)23 ????????????{24 ????????????????foreach (DataRow dr in dt.Rows)25 ????????????????{26 ????????????????????UserInfo userInfo = new UserInfo();27 ????????????????????LoadEntity(userInfo, dr);28 ????????????????????list.Add(userInfo);29 ????????????????}30 ????????????}31 ????????????return list;32 ????????}33 ????????/// <summary>34 ????????/// 将表转为属性35 ????????/// </summary>36 ????????/// <param name="userInfo"></param>37 ????????/// <param name="dr"></param>38 ????????private void LoadEntity(UserInfo userInfo, DataRow dr)39 ????????{40 ????????????userInfo.ID = Convert.ToInt32(dr["id"]);41 ????????????userInfo.UserName = dr["userName"] != DBNull.Value ? dr["userName"].ToString() : string.Empty;42 ????????????userInfo.PassWord = dr["passWord"] != DBNull.Value ? dr["passWord"].ToString() : string.Empty;43 ????????}44 ????????/// <summary>45 ????????/// 删除46 ????????/// </summary>47 ????????/// <param name="id"></param>48 ????????/// <returns></returns>49 ????????public int DeleteEntity(int id)50 ????????{51 ????????????string sql = "DELETE FROM userInfo WHERE id = @id";52 ????????????return SqlHelper.ExecuteNonQuery(sql, CommandType.Text, new SqlParameter("@id", id));53 ????????}54 ????????/// <summary>55 ????????/// 插入56 ????????/// </summary>57 ????????/// <param name="userName"></param>58 ????????/// <param name="passWord"></param>59 ????????/// <returns></returns>60 ????????public int InsertEntity(UserInfo userInfo)61 ????????{62 ????????????string sql = "INSERT INTO userInfo(userName,passWord) VALUES(@userName,@passWord)";63 ????????????return SqlHelper.ExecuteNonQuery(sql, CommandType.Text, new SqlParameter[]{64 ????????????????new SqlParameter("@userName",userInfo.UserName),new SqlParameter("@passWord",userInfo.PassWord)65 ????????????});66 ????????}67 ????????/// <summary>68 ????????/// 修改69 ????????/// </summary>70 ????????/// <param name="userName"></param>71 ????????/// <param name="passWord"></param>72 ????????/// <param name="id"></param>73 ????????/// <returns></returns>74 ????????public int UpdateEntity(UserInfo userInfo)75 ????????{76 ????????????string sql = "UPDATE userInfo SET userName=@userName, passWord=@passWord WHERE id=@id";77 ????????????SqlParameter[] ps = {new SqlParameter("@userName",SqlDbType.NVarChar,32),new SqlParameter("@passWord",SqlDbType.NVarChar,32),new SqlParameter("@id",SqlDbType.Int,4) };78 ????????????return SqlHelper.ExecuteNonQuery(sql, CommandType.Text, new SqlParameter[]{79 ????????????????new SqlParameter("@userName",userInfo.UserName),new SqlParameter("@passWord",userInfo.PassWord),new SqlParameter("@id",userInfo.ID)80 ????????????});81 ????????}82 ????????/// <summary>83 ????????/// 详细84 ????????/// </summary>85 ????????/// <param name="id"></param>86 ????????/// <returns></returns>87 ????????public UserInfo ShowDetail(int id)88 ????????{89 ????????????string sql = "SELECT * FROM userInfo WHERE id = @id";90 ????????????DataTable dt = SqlHelper.GetTable(sql, CommandType.Text, new SqlParameter("@id", id));91 ????????????UserInfo userInfo = new UserInfo();92 ????????????if (dt.Rows.Count > 0)93 ????????????{94 ????????????????LoadEntity(userInfo, dt.Rows[0]);95 ????????????}96 ????????????return userInfo;97 ????????}98 ????}99 }5. BLL层，里面就是把DAL层里的每个方法返回一个值，感觉BLL层没什么用，可能就是DAL层和UI层之间的一个桥梁吧，避免DAL层直接暴露在UI层里。BLL层里只有一个方法UserInfoBll。
UserInfoBll.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using JJW.Model; 6 ?7 namespace JJW.BLL 8 { 9 ????public class UserInfoBll10 ????{11 ????????DAL.UserInfoDal UserInfoDal = new DAL.UserInfoDal();12 ????????public List<UserInfo> GetEntity()13 ????????{14 ????????????return UserInfoDal.GetEntity();15 ????????}16 ????????public int DeleteEntity(int id)17 ????????{18 ????????????return UserInfoDal.DeleteEntity(id);19 ????????}20 ????????public int InsertEntity(UserInfo userInfo)21 ????????{22 ????????????return UserInfoDal.InsertEntity(userInfo);23 ????????}24 ????????public int UpdateEntity(UserInfo userInfo)25 ????????{26 ????????????return UserInfoDal.UpdateEntity(userInfo);27 ????????}28 ????????public UserInfo ShowDetail(int id)29 ????????{30 ????????????return UserInfoDal.ShowDetail(id);31 ????????}32 ????}33 }6. 最后的UI层，也就是WebApp。里面就是增删改查的页面，目前用的都是ashx一般处理程序，后面可能会改成aspx。
首先是web.config设置，这里面有两套登录设置，一个是本地，一个是用户名。
1 <?xml version="1.0" encoding="utf-8"?> 2 ?3 <!-- 4 ??有关如何配置 ASP.NET 应用程序的详细消息，请访问 5 ??http://go.microsoft.com/fwlink/?LinkId=169433 6 ??--> 7 ?8 <configuration> 9 ??<system.web>10 ????<compilation debug="true" targetFramework="4.0" />11 ??</system.web>12 ??<connectionStrings>13 ????<!--<add connectionString="data source=.;initial catalog=jjwdb;integrated security=true;" name="conStr"/>-->14 ????<add connectionString="server=.;uid=sa;pwd=123;database=jjwdb;" name="conStr"/>15 ??</connectionStrings>16 </configuration>
后面是一堆页面，虽然网上粘很繁琐，但为了以后抄的方便，没办法啊。。而且为了不漏下，按字母顺序粘了。
Add.ashx
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using JJW.Model; 6 ?7 namespace JJW.WebApp 8 { 9 ????/// <summary>10 ????/// Add 的摘要说明11 ????/// </summary>12 ????public class Add : IHttpHandler13 ????{14 15 ????????public void ProcessRequest(HttpContext context)16 ????????{17 ????????????context.Response.ContentType = "text/html";18 ????????????UserInfo userInfo = new UserInfo();19 ????????????userInfo.UserName = context.Request["userName"];20 ????????????userInfo.PassWord = context.Request["passWord"];21 ????????????BLL.UserInfoBll UserInfoBll = new BLL.UserInfoBll();22 ????????????UserInfoBll.InsertEntity(userInfo);23 ????????????context.Response.Redirect("UserInfoList.ashx");24 ????????}25 26 ????????public bool IsReusable27 ????????{28 ????????????get29 ????????????{30 ????????????????return false;31 ????????????}32 ????????}33 ????}34 }Add.html
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 </head> 6 <body> 7 ????<form action="Add.ashx" method="post"> 8 ????<table border="1"> 9 ????????<tr>10 ????????????<td>用户名</td>11 ????????????<td><input type="text" name="userName"/></td>12 ????????</tr>13 ????????<tr>14 ????????????<td>密码</td>15 ????????????<td><input type="text" name="passWord"/></td>16 ????????</tr>17 ????????<tr>18 ????????????<td colspan="2"><input type="submit" value="提交"/></td>19 ????????</tr>20 ????</table>21 ????</form>22 </body>23 </html>
DeleteUser.ashx
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 ?6 namespace JJW.WebApp 7 { 8 ????/// <summary> 9 ????/// DeleteUser 的摘要说明10 ????/// </summary>11 ????public class DeleteUser : IHttpHandler12 ????{13 14 ????????public void ProcessRequest(HttpContext context)15 ????????{16 ????????????context.Response.ContentType = "text/html";17 ????????????int id = Convert.ToInt32(context.Request["id"]);18 ????????????BLL.UserInfoBll UserInfoBll = new BLL.UserInfoBll();19 ????????????UserInfoBll.DeleteEntity(id);20 ????????????context.Response.Redirect("UserInfoList.ashx");21 22 ????????}23 24 ????????public bool IsReusable25 ????????{26 ????????????get27 ????????????{28 ????????????????return false;29 ????????????}30 ????????}31 ????}32 }ShowDetail.ashx
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.IO; 6 using JJW.Model; 7 ?8 namespace JJW.WebApp 9 {10 ????/// <summary>11 ????/// ShowDetail 的摘要说明12 ????/// </summary>13 ????public class ShowDetail : IHttpHandler14 ????{15 16 ????????public void ProcessRequest(HttpContext context)17 ????????{18 ????????????context.Response.ContentType = "text/html";19 ????????????string filePath = context.Request.MapPath("ShowDetail.html");20 ????????????string fileContent = File.ReadAllText(filePath);21 ????????????int id = Convert.ToInt32(context.Request["id"]);22 ????????????BLL.UserInfoBll UserInfoBll = new BLL.UserInfoBll();23 ????????????UserInfo userInfo = UserInfoBll.ShowDetail(id);24 ????????????fileContent = fileContent.Replace("$id", userInfo.ID.ToString()).Replace("$userName", userInfo.UserName).Replace("$passWord", userInfo.PassWord);25 ????????????context.Response.Write(fileContent);26 27 28 ????????}29 30 ????????public bool IsReusable31 ????????{32 ????????????get33 ????????????{34 ????????????????return false;35 ????????????}36 ????????}37 ????}38 }ShowDetail.html
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 ????<title></title> 5 </head> 6 <body> 7 ????<table border="1"> 8 ????????<tr> 9 ????????????<td>ID</td>10 ????????????<td>$id</td>11 ????????</tr>12 ????????<tr>13 ????????????<td>用户名</td>14 ????????????<td>$userName</td>15 ????????</tr>16 ????????<tr>17 ????????????<td>密码</td>18 ????????????<td>$passWord</td>19 ????????</tr>20 ????</table>21 </body>22 </html>
Update.ashx
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using JJW.Model; 6 using System.IO; 7 ?8 namespace JJW.WebApp 9 {10 ????/// <summary>11 ????/// Update 的摘要说明12 ????/// </summary>13 ????public class Update : IHttpHandler14 ????{15 ????????public void ProcessRequest(HttpContext context)16 ????????{17 ????????????context.Response.ContentType = "text/html";18 ????????????int id;19 ????????????if (int.TryParse((context.Request["id"]), out id))20 ????????????{21 ????????????????BLL.UserInfoBll UserInfoBll = new BLL.UserInfoBll();22 ????????????????UserInfo userInfo = UserInfoBll.ShowDetail(id);23 ????????????????//userInfo.UserName = context.Request["userName"];24 ????????????????//userInfo.PassWord = context.Request["passWord"];25 ????????????????//UserInfoBll.UpdateEntity(userInfo);26 27 ????????????????string filePath = context.Request.MapPath("Update.html");28 ????????????????string fileContent = File.ReadAllText(filePath);29 ????????????????fileContent = fileContent.Replace("$userName", userInfo.UserName).Replace("$passWord", userInfo.PassWord).Replace("$id",userInfo.ID.ToString());30 ????????????????context.Response.Write(fileContent);31 ????????????????//context.Response.Redirect("UserInfoList.ashx");32 ????????????}33 34 ????????}35 36 ????????public bool IsReusable37 ????????{38 ????????????get39 ????????????{40 ????????????????return false;41 ????????????}42 ????????}43 ????}44 }Update.html
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 ????<title></title> 5 </head> 6 <body> 7 ????<form action="Update2.ashx" method="post"> 8 ????<input type="hidden" name="id" value="$id" /> 9 ????<table>10 ????????<tr>11 ????????????<td>12 ????????????????用户名13 ????????????</td>14 ????????????<td>15 ????????????????<input type="text" name="userName" value="$userName" />16 ????????????</td>17 ????????</tr>18 ????????<tr>19 ????????????<td>20 ????????????????密码21 ????????????</td>22 ????????????<td>23 ????????????????<input type="text" name="passWord" value="$passWord" />24 ????????????</td>25 ????????</tr>26 ????????<tr>27 ????????????<td colspan="2">28 ????????????????<input type="submit" value="提交" />29 ????????????</td>30 ????????</tr>31 ????</table>32 ????</form>33 </body>34 </html>
Update2.ashx
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using JJW.Model; 6 ?7 namespace JJW.WebApp 8 { 9 ????/// <summary>10 ????/// Update2 的摘要说明11 ????/// </summary>12 ????public class Update2 : IHttpHandler13 ????{14 15 ????????public void ProcessRequest(HttpContext context)16 ????????{17 ????????????context.Response.ContentType = "text/html";18 ????????????UserInfo userInfo = new UserInfo();19 ????????????userInfo.ID = Convert.ToInt32(context.Request["id"]);20 ????????????userInfo.UserName = context.Request["userName"].ToString();21 ????????????userInfo.PassWord = context.Request["passWord"].ToString();22 ????????????BLL.UserInfoBll UserInfoBll = new BLL.UserInfoBll();23 ????????????UserInfoBll.UpdateEntity(userInfo);24 ????????????context.Response.Redirect("UserInfoList.ashx");25 ????????}26 27 ????????public bool IsReusable28 ????????{29 ????????????get30 ????????????{31 ????????????????return false;32 ????????????}33 ????????}34 ????}35 }UserInfoList.ashx
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.IO; 6 using JJW.Model; 7 using System.Text; 8 ?9 namespace JJW.WebApp10 {11 ????/// <summary>12 ????/// UserInfoList 的摘要说明13 ????/// </summary>14 ????public class UserInfoList : IHttpHandler15 ????{16 17 ????????public void ProcessRequest(HttpContext context)18 ????????{19 ????????????context.Response.ContentType = "text/html";20 ????????????string filePath = context.Request.MapPath("UserInfoList.html");21 ????????????string fileContent = File.ReadAllText(filePath);22 ????????????BLL.UserInfoBll UserInfoBll = new BLL.UserInfoBll();23 ????????????List<UserInfo> list = UserInfoBll.GetEntity();24 ????????????StringBuilder sb = new StringBuilder();25 ????????????foreach (UserInfo userInfo in list)26 ????????????{27 ????????????????sb.AppendFormat("<tr><td>{0}</td><td>{1}</td><td>{2}</td><td><a href=‘Update.ashx?id={0}‘>修改</a></td><td><a href=‘DeleteUser.ashx?id={0}‘>删除</a></td><td><a href=‘ShowDetail.ashx?id={0}‘>详细</a></td></tr>", userInfo.ID, userInfo.UserName, userInfo.PassWord);28 ????????????}29 ????????????fileContent = fileContent.Replace("$tbody", sb.ToString());30 ????????????context.Response.Write(fileContent);31 ????????}32 33 ????????public bool IsReusable34 ????????{35 ????????????get36 ????????????{37 ????????????????return false;38 ????????????}39 ????????}40 ????}41 }UserInfoLIst.html
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 ????<title></title> 5 </head> 6 <body> 7 ????<h1>用户表</h1> 8 ????<a href ="Add.html">添加用户</a> 9 ????<table border="1">10 ????????<tr>11 ????????????<th>12 ????????????????ID13 ????????????</th>14 ????????????<th>15 ????????????????用户名16 ????????????</th>17 ????????????<th>18 ????????????????密码19 ????????????</th>20 ????????????<th>21 ????????????????修改22 ????????????</th>23 ????????????<th>24 ????????????????删除25 ????????????</th>26 ????????????<th>27 ????????????????详细28 ????????????</th>29 ????????</tr>30 ????????$tbody31 ????</table>32 </body>33 </html>
运行结果：
总结：
至今没有一天之内完整的写一遍，其实需要每天都练习的，里面有很多细节，特别是DAL层里的数据库操作，再次许愿，十月份能把asp.net部分学习完！嘻嘻(#^.^#)
ASP.NET学习笔记（3）——用户增删改查（三层）
原文地址：http://www.cnblogs.com/Jacklovely/p/7631511.html