手動搭建簡單的三層框架
阿新 • • 發佈：2018-11-10
第一、三層框架可以手動搭建，也可以用動軟程式碼生成器來實現，本文使用手動搭建來做，首先先建立一個ASP.Net應用程式ThreeLayerWebDemo，然後在解決方案下分別建立四個類庫BLL、DAL、Model、Common。
第二、在ThreeLayerWebDemo中新建一個資料夾News,在News資料夾下建立一個一般處理程式NewsList.ashx和一個NewsListTemp.html模板，並且將以上各個類庫裡的類名做更改，改為容易記且與類的功能屬性一致得名字。
NewsList.ashx程式碼如下：
using Model; using System; using System.Collections.Generic;using System.IO; using System.Linq; using System.Text; using System.Web; namespace ThreeLayerDemo.News { /// <summary> /// NewsList 的摘要說明 /// </summary> public class NewsList : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType= "text/html"; BLL.NewsInfoService NewsInfoService = new BLL.NewsInfoService();//引用BLL List<NewsInfo> getNews= NewsInfoService.GetAllNews();//獲得資料庫裡的新聞資訊 StringBuilder sb = new StringBuilder(); foreach (var item in getNews) {//dId, dTId, dName, dContent, dlnTime, dEditTime, disDeletedsb.AppendFormat("<tr><td>{0}</td><td>{1}</td><td>{2}</td><td>{3}</td><td>{4}</td><td>{5}</td><td><a href='#'>操作</a></td></tr>", item.dId, item.dName, item.dContent, item.dlnTime, item.dEditTime, item.disDelete); } string TempString = File.ReadAllText(context.Request.MapPath("NewsListTemp.html")); string result= TempString.Replace("@trBody", sb.ToString()); context.Response.Write(result); } public bool IsReusable { get { return false; } } } }
NewListTemp.html模板中的程式碼如下：
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title></title> <meta charset="utf-8" /> </head> <body> <table border="1" width="6"> <tr> <th>dId</th><th>dName</th><th>dContent</th><th>dlnTime</th><th>dEditTime</th><th>disDeleted</th> <th>詳 情</th> </tr> @trBody </table> </body> </html>
在以上一般處理程式NewsList中，當程式執行該程式碼時（該處的方法需要手動生成），則跳轉到BLL類庫下的NewsInfoService類中，並且在該類中生成GetAllNews（）方法。
BLL.NewsInfoService NewsInfoService = new BLL.NewsInfoService();//引用BLL List<NewsInfo> getNews= NewsInfoService.GetAllNews();//獲得資料庫裡的新聞資訊
NewsInfoService類中的程式碼如下：
using Model; using DAL;
using System.Collections.Generic; namespace BLL { public class NewsInfoService { private NewsInfoDal newsInfoDal = new NewsInfoDal();//為什麼要寫為Private public List<NewsInfo> GetAllNews() { return newsInfoDal.GetAllNews(); } } }
Model類庫下的NewsInfo類主要用於存放從資料庫中採集到的資料，用屬性來儲存，程式碼如下
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Model { public class NewsInfo { //dId, dTId, dName, dContent, dlnTime, dEditTime, disDeleted public int dId { get; set; } public string dName { get; set; } public string dContent { get; set; } public DateTime dlnTime { get; set; } public DateTime dEditTime { get; set; } public int disDelete { get; set; } } }
DAL類庫中的NewsInfoDAL這個類主要是用來建立資料庫連線、操作資料庫使用，在該類庫中還需要封裝一個SQLHelper類。
NewsInfoDAL.cs 中的程式碼如下所示：
using Model; using System; using System.Collections.Generic; using System.Data; using System.Data.SqlClient; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DAL { public class NewsInfoDal { List<NewsInfo> list = new List<NewsInfo>(); public List<NewsInfo> GetAllNews() { string sql = "select dId, dName, dContent, dlnTime, dEditTime, disDeleted from ContentInfo"; //dId, dTId, dName, dContent, dlnTime, dEditTime, disDeleted using (SqlDataReader reader=SqlHelper.ExecuteReader(sql)) { if (reader.HasRows) { while (reader.Read()) { NewsInfo dt = new NewsInfo(); dt.dId = reader.GetInt32(0); dt.dName = reader.GetString(1); dt.dContent = reader.GetString(2); dt.dlnTime = reader.GetDateTime(3); dt.dEditTime = reader.GetDateTime(4); dt.disDelete = reader.GetInt32(5); list.Add(dt); } } return list; } } } }
下面在DAL類庫下封裝一個SQLHelper
using System; using System.Collections.Generic; using System.Configuration; using System.Data.SqlClient; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DAL { public static class SqlHelper { //寫三個方法：增刪改，返回一個值，返回多行或多個值 //將連線資料庫的字串寫在一個引用中 private static readonly string constr = ConfigurationManager.ConnectionStrings ["Mysqlserver"].ConnectionString;// //寫一個方法來執行增刪改 public static int ExecuteNonQuery(string sql,params SqlParameter[] pms) { using (SqlConnection con=new SqlConnection (constr)) { using (SqlCommand cmd=new SqlCommand (sql,con)) { if(pms!=null) { cmd.Parameters.AddRange(pms); } con.Open(); return cmd.ExecuteNonQuery(); } } } /// <summary> /// 寫一個方法執行返回一個值的 /// </summary> /// <returns></returns> public static object ExecuteScalar(string sql,params SqlParameter[] pms) { using (SqlConnection con=new SqlConnection (constr )) { using (SqlCommand cmd=new SqlCommand (sql,con)) { if(pms!=null) { cmd.Parameters.AddRange(pms);//把sql中的引數給執行命令 } con.Open(); return cmd.ExecuteScalar(); } } } /// <summary> /// 寫一個方法來返回多個值 /// </summary> /// <param name="sql"></param> /// <param name="pms"></param> /// <returns></returns> public static SqlDataReader ExecuteReader(string sql,params SqlParameter[] pms) { SqlConnection con = new SqlConnection(constr); using (SqlCommand cmd = new SqlCommand(sql, con)) { if (pms != null) { cmd.Parameters.AddRange(pms); } try { con.Open(); return cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);//這樣返回值的時候就將連線物件關閉了 } catch { con.Close(); con.Dispose(); throw; } } } } }
資料庫連線字串寫在Web.config中,(注意：在WinForm中則寫在App.config中)
<?xml version="1.0" encoding="utf-8"?> <!-- 有關如何配置 ASP.NET 應用程式的詳細資訊，請訪問 http://go.microsoft.com/fwlink/?LinkId=169433 --> <configuration> <connectionStrings> <add name="Mysqlserver" connectionString="server=WIN7U-20170517Z;uid=sa;pwd=zhangyukui283166; database=2018Study"/> </connectionStrings> <system.web> <compilation debug="true" targetFramework="4.5.2"/> <httpRuntime targetFramework="4.5.2"/> <httpModules> <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web"/> </httpModules> </system.web> <system.codedom> <compilers> <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701"/> <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+"/> </compilers> </system.codedom> <system.webServer> <validation validateIntegratedModeConfiguration="false"/> <modules> <remove name="ApplicationInsightsWebTracking"/> <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler"/> </modules> </system.webServer> </configuration>