ASP.NET三层架构详解 如何实现三层架构

 /*==============================================================*/ /* DBMS name:   Microsoft SQL Server 2000          */ /*==============================================================*/ if exists (select 1 from sysobjects where id = object_id('newsContent') and  type = 'U') drop table newsContent go /*==============================================================*/ /* Table: newsContent                      */ /*==============================================================*/ create table newsContent ( ID      int       identity(1,1)  primary key, Title     nvarchar(50)   not null, Content    ntext      not null, AddDate   datetime     not null, CategoryID  int       not null ) go 

 using System; using System.Configuration; namespace Utility { /// 
 /// ConnectionInfo 的摘要说明。 /// 
 public class ConnectionInfo { public static string GetSqlServerConnectionString() { return ConfigurationSettings.AppSettings["SQLConnString"]; } } } 

 using System; using System.Data; using System.Data.SqlClient; using DBUtility; namespace SQLServerDAL { /// 
 /// SqlHelper 的摘要说明。 /// 
 public abstract class SqlHelper { public static readonly string CONN_STR = ConnectionInfo.GetSqlServerConnectionString(); /// 
 /// 用提供的函数，执行SQL命令，返回一个从指定连接的数据库记录集 /// 
 ///  /// 例如： /// SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); ///  /// SqlConnection有效的SQL连接字符串 /// CommandType：CommandType.Text、CommandType.StoredProcedure /// SQL语句或存储过程 /// SqlParameter[]参数数组 /// SqlDataReader：执行结果的记录集 public static SqlDataReader ExecuteReader(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms) { SqlCommand cmd = new SqlCommand(); SqlConnection conn = new SqlConnection(connString); // 我们在这里用 try/catch 是因为如果这个方法抛出异常，我们目的是关闭数据库连接，再抛出异常， // 因为这时不会有DataReader存在，此后commandBehaviour.CloseConnection将不会工作。 try { PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms); SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection); cmd.Parameters.Clear(); return rdr; } catch { conn.Close(); throw; } } /// 
 /// 为执行命令做好准备：打开数据库连接，命令语句，设置命令类型（SQL语句或存储过程），函数语取。 /// 
 /// SqlCommand 组件 /// SqlConnection 组件 /// SqlTransaction 组件，可以为null /// 语句类型：CommandType.Text、CommandType.StoredProcedure /// SQL语句，可以为存储过程 /// SQL参数数组 private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms) { if (conn.State != ConnectionState.Open) conn.Open(); cmd.Connection = conn; cmd.CommandText = cmdText; if (trans != null) cmd.Transaction = trans; cmd.CommandType = cmdType; if (cmdParms != null) { foreach (SqlParameter parm in cmdParms) cmd.Parameters.Add(parm); } } } } 

 using System; using System.Data; using System.Data.SqlClient; using Model; using IDAL; namespace SQLServerDAL { /// 
 /// Content 的摘要说明。 /// 
 public class Content:IContent { private const string PARM_ID = "@ID"; private const string SQL_SELECT_CONTENT = "Select ID, Title, Content, AddDate, CategoryID From newsContent Where ID = @ID"; public ContentInfo GetContentInfo(int id) { //创意文章内容类 ContentInfo ci = null; //创建一个参数 SqlParameter parm = new SqlParameter(PARM_ID, SqlDbType.BigInt, 8); //赋上ID值 parm.Value = id; using(SqlDataReader sdr = SqlHelper.ExecuteReader(SqlHelper.CONN_STR, CommandType.Text, SQL_SELECT_CONTENT, parm)) { if(sdr.Read()) { ci = new ContentInfo(sdr.GetInt32(0),sdr.GetString(1), sdr.GetString(2), sdr.GetDateTime(3), sdr.GetInt32(4), sdr.GetInt32(5), sdr.GetString(6)); } } return ci; } } } 

 using System; namespace Model { /// 
 /// Class1 的摘要说明。 /// 
 public class ContentInfo { private int _ID; private string _Content; private string _Title; private string _From; private DateTime _AddDate; private int _clsID; private int _tmpID; /// 
 /// 文章内容构造函数 /// 
 /// 文章流水号ID /// 文章内容 /// 文章标题 /// 文章来源 /// 文章的分类属性ID /// 文章的模板属性ID public ContentInfo(int id,string title,string content,string from,DateTime addDate,int clsid,int tmpid ) { this._ID = id; this._Content = content; this._Title = title; this._From = from; this._AddDate = addDate; this._clsID = clsid; this._tmpID = tmpid; } //属性 public int ID { get  { return _ID; } } public string Content { get  { return _Content; } } public string Title { get  { return _Title; } } public string From { get  { return _From; } } public DateTime AddDate { get  { return _AddDate; } } public int ClsID { get  { return _clsID; } } public int TmpID { get  { return _tmpID; } } } } 

 using System; using Model; namespace IDAL { /// 
 /// 文章内容操作接口 /// 
 public interface IContent { /// 
 /// 取得文章的内容。 /// 
 /// 文章的ID ///  ContentInfo GetContentInfo(int id); } } 

 using System; using System.Reflection; using System.Configuration; using IDAL; namespace DALFactory { /// 
 /// 工产模式实现文章接口。 /// 
 public class Content { public static IDAL.IContent Create() { // 这里可以查看 DAL 接口类。 string path = System.Configuration.ConfigurationSettings.AppSettings["WebDAL"].ToString(); string className = path+".Content"; // 用配置文件指定的类组合 return (IDAL.IContent)Assembly.Load(path).CreateInstance(className); } } } 

 using System; using Model; using IDAL; namespace BLL { /// 
 /// Content 的摘要说明。 /// 
 public class Content { public ContentInfo GetContentInfo(int id) { // 取得从数据访问层取得一个文章内容实例 IContent dal = DALFactory.Content.Create(); // 用DAL查找文章内容 return dal.GetContentInfo(id); } } } 

 <%@ Page language="c#" Codebehind="WebUI.aspx.cs" AutoEventWireup="false" Inherits="Web.WebUI" %>   
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 using System; using System.Collections; using System.ComponentModel; using System.Data; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; using BLL; using Model; namespace myWeb { /// 
 /// WebForm1 的摘要说明。 /// 
 public class WebUI : System.Web.UI.Page { protected System.Web.UI.WebControls.Label lblTitle; protected System.Web.UI.WebControls.Label lblDataTime; protected System.Web.UI.WebControls.Label lblContent; protected System.Web.UI.WebControls.Label lblMsg; private ContentInfo ci ; private void Page_Load(object sender, System.EventArgs e) { if(!Page.IsPostBack) { GetContent("1"); } } private void GetContent(string id) { int ID = WebComponents.CleanString.GetInt(id); Content c = new Content(); ci = c.GetContentInfo(ID); if(ci!=null) { this.lblTitle.Text = ci.Title; this.lblDataTime.Text = ci.AddDate.ToString("yyyy-MM-dd"); this.lblContent.Text = ci.Content; } else { this.lblMsg.Text = "没有找到这篇文章"; } } #region Web 窗体设计器生成的代码 override protected void OnInit(EventArgs e) { // // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。 // InitializeComponent(); base.OnInit(e); } /// 
 /// 设计器支持所需的方法 - 不要使用代码编辑器修改 /// 此方法的内容。 /// 
 private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); } #endregion } } 

 using System; using System.Text; namespace myWeb.WebComponents { /// 
 /// CleanString 的摘要说明。 /// 
 public class CleanString { public static int GetInt(string inputString) { try { return Convert.ToInt32(inputString); } catch { return 0; } } public static string InputText(string inputString, int maxLength) { StringBuilder retVal = new StringBuilder(); // check incoming parameters for null or blank string if ((inputString != null) && (inputString != String.Empty)) { inputString = inputString.Trim(); //chop the string incase the client-side max length //fields are bypassed to prevent buffer over-runs if (inputString.Length > maxLength) inputString = inputString.Substring(0, maxLength); //convert some harmful symbols incase the regular //expression validators are changed for (int i = 0; i ': retVal.Append(">"); break; default: retVal.Append(inputString[i]); break; } } // Replace single quotes with white space retVal.Replace("'", " "); } return retVal.ToString(); } } }