使用三层架构制作聊天室

 聊天室设计了两个表，一个表用于存放用户的登录信息，一个表用于存放用户的留言信息。

在 Models中定义的两个实体类Message和User

在DAL中定义两个类UserDAL和MessageDAL

UserDAL中

     public static User GetUser(string userName)
        {
            string str = "select * from T_user where userName=@userName";
            SqlParameter[] para = {new SqlParameter("@userName",SqlDbType.NVarChar) };
            para[0].Value = userName;
            SqlHelper helper = new SqlHelper();
            DataTable dt = helper.ExecuteReturnDataTable(str,para,CommandType.Text);
            if (dt.Rows.Count > 0)
            {
                //找到该用户信息后，保存在user对象中，并且返回这个对象
                User user = new User();
                user.UserId = (int)(dt.Rows[0]["userId"]);
                user.UserName = (string)(dt.Rows[0]["userName"].ToString());
                user.UserPsd = (string)(dt.Rows[0]["userPsd"].ToString());
                return user;

            }
            else
            {
                //没有找到用户
                return null;
            }

MessageDAL中

public class MessageDAL
    {
        /// <summary>
        /// 向信息表中添加信息
        /// </summary>
        /// <param name="message"></param>
        /// <returns></returns>
        public static bool Addmessage(Message message)
        {
            string str = "insert into T_message(messageTime,userName,emotion,messageContent,color,face) values(@messageTime,@userName,@emotion,@messageContent,@color,@face)";
            SqlParameter[] para = {
                                    new SqlParameter("@messageTime",SqlDbType.DateTime),
                                    new SqlParameter("@userName",SqlDbType.NVarChar),
                                    new SqlParameter("@emotion",SqlDbType.NVarChar),
                                    new SqlParameter("@messageContent",SqlDbType.NVarChar),
                                    new SqlParameter("@color",SqlDbType.NVarChar),
                                    new SqlParameter("@face",SqlDbType.NVarChar)
                                  };
            para[0].Value = message.MessageTime;
            para[1].Value = message.UserName;
            para[2].Value = message.Emotion;
            para[3].Value = message.MessageContent;
            para[4].Value = message.Color;
            para[5].Value = message.Face;
            SqlHelper helper = new SqlHelper();
            int result = -1;
            result = helper.ExecuteReturnInt(str, para, CommandType.Text);
            if (result > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
           
        /// <summary>
        /// 把数据行打包成Message数据实体
        /// </summary>
        /// <param name="dataRow">一条记录</param>
        /// <returns>Message实体</returns>
        public static Message GetMessageFromDataRow(DataRow dataRow)
        {
            Message message = new Message();
            message.UserName = dataRow["userName"].ToString();
            message.MessageContent = dataRow["messageContent"].ToString();
            message.Emotion = dataRow["emotion"].ToString();
            message.Color = dataRow["color"].ToString();
            message.MessageTime = dataRow["messageTime"].ToString();
            message.Face = dataRow["face"].ToString();
            return message;
        }

        /// <summary>
        /// 获得信息表中前10条用户的数据
        /// </summary>
        /// <param name="message"></param>
        /// <returns></returns>
        public static List<Message> Selectmessage()
        {
            List<Message> messagelist = new List<Models.Message>();
            string str = "select top(10) * from T_message order by messageTime desc";
            SqlHelper helper = new SqlHelper();
            DataTable dt = helper.ExecuteReturnDataTable(str, null, CommandType.Text);
            if (dt.Rows.Count > 0)
            {
                foreach (DataRow row in dt.Rows)
                {
                    messagelist.Add(GetMessageFromDataRow(row));
                }

                return messagelist;
            }
            return null;

        }
    }
在BLL中定义MessageBLL和UserBLL

MessageBLL中

public class   MessageBLL

{
        /// <summary>
        /// 获得信息表中前10条用户的数据
        /// </summary>
        /// <returns></returns>
        public static List<Message> Selectmessage()
        {
            return MessageDAL.Selectmessage();
        }
       
        /// <summary>
        /// 发表留言
        /// </summary>
        /// <param name="message"></param>
        /// <returns></returns>
        public static bool Addmessage(Message message)
        {
           return MessageDAL.Addmessage(message);
        }
    }

UserBLL中

public class UserBLL
    {
        /// <summary>
        /// 登陆验证
        /// </summary>
        public static bool login(string userName,string userPsd,out User validUser)
        {
            User user = UserDAL.GetUser(userName);
            //没有该用户信息
            if (user == null)
            {
                validUser = null;
                return false;
            }
            //如果登陆的用户名与数据库中的用户名相同时，该用户为合法用户
            if (user.UserName == userName)
            {
                validUser = user;
                return true;
            }
            else
            {
                validUser = null;
                return false;
            }
        }
    }

 

在用户界面层

登录界面

protected void bt_Login_Click(object sender, EventArgs e)
    {
        User user;
       if (this.txt_username.Text.Trim().Length == 0)
        {
            Response.Write("<script>alert('请输入用户名')</script>");
        }
        if (this.txt_userpsd.Text.Trim().Length == 0)
        {
            Response.Write("<script>alert('请输入密码')</script>");
        }
        if (UserBLL.login(this.txt_username.Text, this.txt_userpsd.Text, out user))
        {
            Session["user"] = user;
            Response.Redirect("index.aspx");
        }
        else
        {
            Response.Write("<script>alert('您输入的用户名或者密码错误')</script>");
        }
    }

 

聊天室页面

aspx

    <div>
        <div>
            <p align="center" style="height: 41px; font-style: normal; font-size: x-large; color: Blue;">
                *欢迎<asp:Label ID="L_name" runat="server" Text=""></asp:Label>来到MyChatRoom*<br />
                <asp:Button ID="bt_return" runat="server" Text="返回登录" OnClick="bt_return_Click" /></p>
        </div>
        <table style="width: 100%;">
            <tr>
                <td class="style1">
                    <iframe src="Iframe.aspx" scrolling="yes" style="width: 654px"></iframe>
                </td>
            </tr>
            <tr>
                <td class="style1">
                    <asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="~/image/1.jpg"
                        onclick="ImageButton1_Click" />
                    <asp:ImageButton ID="ImageButton2" runat="server" ImageUrl="~/image/2.jpg"
                        onclick="ImageButton2_Click" />
                    <asp:ImageButton ID="ImageButton3" runat="server"  ImageUrl="~/image/3.jpg"
                        onclick="ImageButton3_Click"/>
                    <asp:ImageButton ID="ImageButton4" runat="server"  ImageUrl="~/image/4.jpg"
                        onclick="ImageButton4_Click"/>
                    <asp:ImageButton ID="ImageButton5" runat="server"  ImageUrl="~/image/5.jpg"
                        onclick="ImageButton5_Click"/>
                </td>
            </tr>
            <tr>
                <td class="style1">
                    <asp:TextBox ID="txt_content" runat="server" TextMode="MultiLine" Height="48px" Width="447px"></asp:TextBox>
                </td>
            </tr>
        </table>
        <table style="width: 40%;">
            <tr>
                <td align="right">
                    <asp:DropDownList ID="ddl_color" runat="server">
                        <asp:ListItem Value="black" Selected="True">黑色</asp:ListItem>
                        <asp:ListItem Value="red">红色</asp:ListItem>
                        <asp:ListItem Value="blue">蓝色</asp:ListItem>
                        <asp:ListItem Value="purple">紫色</asp:ListItem>
                    </asp:DropDownList>
                </td>
                <td align="left">
                    <asp:DropDownList ID="ddl_emotion" runat="server">
                        <asp:ListItem Value="微笑的" Selected="True">微笑的</asp:ListItem>
                        <asp:ListItem Value="高兴的">高兴的</asp:ListItem>
                        <asp:ListItem Value="伤心的">伤心的</asp:ListItem>
                        <asp:ListItem Value="沮丧的">沮丧的</asp:ListItem>
                    </asp:DropDownList>
                </td>
                <td align="left">
                    <asp:Button ID="bt_talk" runat="server" Text="发言" OnClick="bt_talk_Click" />
                </td>
                <td align="left">
                    <asp:Button ID="bt_leave" runat="server" Text="离开" OnClick="bt_leave_Click" />
                </td>
            </tr>
        </table>
    </div>

 

aspx.cs

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            if (Session["user"] != null)
            {
                L_name.Text = ((User)(Session["user"])).UserName;
            }
            else
            {
                Response.Write("<script>alert('请先登录');location.href('Login.aspx')</script>");
            }

        }
    }
    /// <summary>
    /// 发言
    /// </summary>
    protected void bt_talk_Click(object sender, EventArgs e)
    {
        if (Session["user"] != null)
        {
            string messageinfo = txt_content.Text.Trim();
            //使用正则表达式的Replace方法
            string result1 = Regex.Replace(messageinfo, @"{!", "<img src='image/");
            string result2 = Regex.Replace(result1, @"!}", ".jpg'/>");
            Message mess = new Message();
            DateTime date = DateTime.Now;
            mess.MessageTime = date.ToString();
            mess.UserName = ((User)(Session["user"])).UserName;
            mess.Emotion = ddl_emotion.SelectedValue;
            mess.MessageContent = result2;
            mess.Color = ddl_color.SelectedValue;
            mess.Face = "";
            bool result=MessageBLL.Addmessage(mess);
            if (result==true)
            {
                Response.Write("<script>alert('发言成功')</script>");
            }
            else
            {
                Response.Write("<script>alert('发言失败')</script>");
            }
        }
    }

    /// <summary>
    /// 离开
    /// </summary>
    protected void bt_leave_Click(object sender, EventArgs e)
    {
        //清除对象
        Session.Contents.Remove("user");
        Response.Redirect("Login.aspx");
    }

    /// <summary>
    /// 返回登录
    /// </summary>
   protected void bt_return_Click(object sender, EventArgs e)
    {
        Response.Redirect("Login.aspx");
    }

   

    /// <summary>
    /// 在文本框中插入表情
    /// </summary>

    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    {
        txt_content.Text += "{!1!}"; //1是图片的名称，下同
    }
    protected void ImageButton2_Click(object sender, ImageClickEventArgs e)
    {
        txt_content.Text += "{!2!}";
    }
    protected void ImageButton3_Click(object sender, ImageClickEventArgs e)
    {
        txt_content.Text += "{!3!}";
    }
    protected void ImageButton4_Click(object sender, ImageClickEventArgs e)
    {
        txt_content.Text += "{!4!}";
    }
    protected void ImageButton5_Click(object sender, ImageClickEventArgs e)
    {
        txt_content.Text += "{!5!}";
    }

Iframe.aspx

 <form id="form1" runat="server">
    <div>
        <asp:DataList ID="dl_iframe" runat="server">
            <ItemTemplate>
                <div style=' color:<%#Eval("color")%>'>
                    <%#Eval("messageTime") %>
                    <%#"("+Eval("userName")+")" %>
                    <%#Eval("emotion")+"说：" %>
                    <%#Eval("messageContent") %>
                </div>
            </ItemTemplate>
        </asp:DataList>
    </div>
    </form>

 

Iframe.aspx.cs

protected void Page_Load(object sender, EventArgs e)
    {

        if (!IsPostBack)
        {
            //messagelist就相当于一个数据表
            List<Message>  messagelist = MessageBLL.Selectmessage();
            dl_iframe.DataSource = messagelist;
            dl_iframe.DataBind();
           
        }
    }

在三层架构中，在DAL层中的数据要以表的形式在页面中显示，可以用List来实现，如果List<Message> messagelist = new List<Models.Message>();

Message message = new Message();

定义一个messagelist对象，将一个个message实体放在里面，然后在aspx.cs 中可以直接将messagelist赋给数据源，

如List<Message>  messagelist = MessageBLL.Selectmessage();
            dl_iframe.DataSource = messagelist;
            dl_iframe.DataBind();

 

 

 

 

 

      

 

 

 

 

1、  Models---为实体类库

实体类库是作为三成架构的辅助类库存在，数据在传递时都是传递一个封装好的实体；

数据库中一个表对应一个实体

2、  DAL----DATA ACCESS LAYER:数据访问层

数据库中一个表对应一个类文件，其中定义对这个表的增删改查等具体的数据库操作；

SQLhelper是最基本的数据库访问类，也放在该类库中

3、  BLL----Business Logic Layer：业务逻辑层

业务逻辑层中的类对具体的业务进行定义，需要调用DAL层去执行命令

4、Web(UI)---User Interface Layer：用户界面层

用户界面层是直接和用户打交道的，UI层要调用BLL层的类来实现具体的操作