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POPresentation, Business and Data Layer
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  1. POPresentation, Business and Data Layer
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    copied!<p>I just started programming in C# and was reading about dividing your application / website into the three different layers was the best practice but I am having a hard time understanding exactly how. Im working on a pet project to lean more about C# but I dont want to start on any bad habits. Can you look at what I have and see if I am doing this right? Offer some hints suggestions as to how to break everything down to the different layers? </p> <p><strong>Presentation Layer</strong></p> <pre><code>&lt;%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %&gt; &lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt; &lt;head runat="server"&gt; &lt;title&gt;Project: Ruth&lt;/title&gt; &lt;link href="CSS/StyleSheet.css" rel="stylesheet" type="text/css" /&gt; &lt;/head&gt; &lt;body&gt; &lt;form id="form1" runat="server"&gt; &lt;div class="Body"&gt; &lt;div class="Header"&gt; &lt;div class="Nav"&gt; &lt;img src="images/Header_Main.gif" alt="" width="217" height="101" /&gt; &lt;div class="Menu"&gt; &lt;a href="Default.aspx"&gt; &lt;img src="images/Header_Home-Off.gif" alt="" /&gt;&lt;/a&gt; &lt;a href="Default.aspx"&gt; &lt;img src="images/Header_About-Off.gif" alt="" /&gt;&lt;/a&gt; &lt;a href="Register.aspx"&gt; &lt;img src="images/Header_Register-Off.gif" alt="" /&gt;&lt;/a&gt; &lt;a href="Default.aspx"&gt; &lt;img src="images/Header_Credits-Off.gif" alt="" /&gt;&lt;/a&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class="Content"&gt; &lt;div class="CurrentlyListening"&gt; &lt;asp:Label ID="lblCurrentListen" runat="server" Text="(Nothing Now)" CssClass="Txt"&gt;&lt;/asp:Label&gt; &lt;/div&gt; &lt;asp:GridView ID="gvLibrary" runat="server" AutoGenerateColumns="False" DataKeyNames="lib_id" DataSourceID="sdsLibrary" EmptyDataText="There are no data records to display." Width="760" GridLines="None"&gt; &lt;RowStyle CssClass="RowStyle" /&gt; &lt;AlternatingRowStyle CssClass="AltRowStyle" /&gt; &lt;HeaderStyle CssClass="HeaderStyle" /&gt; &lt;Columns&gt; &lt;asp:BoundField DataField="artist_name" HeaderText="Artist" SortExpression="artist_name" HeaderStyle-Width="200" /&gt; &lt;asp:BoundField DataField="album_title" HeaderText="Album" SortExpression="album_title" HeaderStyle-Width="200" /&gt; &lt;asp:BoundField DataField="song_title" HeaderText="Track" SortExpression="song_title" HeaderStyle-Width="200" /&gt; &lt;asp:TemplateField HeaderText="DL"&gt; &lt;ItemTemplate&gt; &lt;a href="http://####/Proj_Ruth/Data/&lt;%# Eval("file_path") %&gt;" class="lnk"&gt;Link&lt;/a&gt; &lt;/ItemTemplate&gt; &lt;/asp:TemplateField&gt; &lt;/Columns&gt; &lt;/asp:GridView&gt; &lt;asp:SqlDataSource ID="sdsLibrary" runat="server" ConnectionString="&lt;%$ ConnectionStrings:MusicLibraryConnectionString %&gt;" DeleteCommand="DELETE FROM [Library] WHERE [lib_id] = @lib_id" InsertCommand="INSERT INTO [Library] ([artist_name], [album_title], [song_title], [file_path]) VALUES (@artist_name, @album_title, @song_title, @file_path)" ProviderName="&lt;%$ ConnectionStrings:MusicLibraryConnectionString.ProviderName %&gt;" SelectCommand="SELECT [lib_id], [artist_name], [album_title], [song_title], [file_path] FROM [Library] ORDER BY [artist_name], [album_title]" UpdateCommand="UPDATE [Library] SET [artist_name] = @artist_name, [album_title] = @album_title, [song_title] = @song_title, [file_path] = @file_path WHERE [lib_id] = @lib_id"&gt; &lt;DeleteParameters&gt; &lt;asp:Parameter Name="lib_id" Type="Int32" /&gt; &lt;/DeleteParameters&gt; &lt;InsertParameters&gt; &lt;asp:Parameter Name="artist_name" Type="String" /&gt; &lt;asp:Parameter Name="album_title" Type="String" /&gt; &lt;asp:Parameter Name="song_title" Type="String" /&gt; &lt;asp:Parameter Name="file_path" Type="String" /&gt; &lt;/InsertParameters&gt; &lt;UpdateParameters&gt; &lt;asp:Parameter Name="artist_name" Type="String" /&gt; &lt;asp:Parameter Name="album_title" Type="String" /&gt; &lt;asp:Parameter Name="song_title" Type="String" /&gt; &lt;asp:Parameter Name="file_path" Type="String" /&gt; &lt;asp:Parameter Name="lib_id" Type="Int32" /&gt; &lt;/UpdateParameters&gt; &lt;/asp:SqlDataSource&gt; &lt;/div&gt; &lt;/div&gt; &lt;/form&gt; &lt;/body&gt; &lt;/html&gt; </code></pre> <p><strong>Business Layer</strong></p> <pre><code>using System; using System.Collections.Generic; using System.Linq; using System.Web; public class User { DA da = new DA(); public string FirstName { get; set; } public string LastName { get; set; } public string EmailAddress { get; set; } public string Password { get; set; } public string AccessCode { get; set; } public User(string firstName, string lastName, string emailAddress, string password, string accessCode) { FirstName = firstName; LastName = lastName; EmailAddress = emailAddress; Password = password; AccessCode = accessCode; } public void CreateUser(User newUser) { if (da.IsValidAccessCode(newUser.AccessCode)) { da.CreateUser(newUser); } } } </code></pre> <p><strong>Data Access Layer (DAL)</strong></p> <pre><code>using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Data; using System.Data.SqlTypes; using System.Data.SqlClient; using System.Configuration; public class DA { public DA() { } public bool IsValidAccessCode(string accessCode) { bool isValid = false; int count = 0; using (SqlConnection sqlCnn = new SqlConnection(ConfigurationManager.ConnectionStrings["MusicLibraryConnectionString"].ConnectionString)) { sqlCnn.Open(); using (SqlCommand sqlCmd = new SqlCommand(String.Format("SELECT COUNT(*) FROM [AccessCodes] WHERE [accessCode_accessCode] = '{0}';", accessCode), sqlCnn)) { count = (int)sqlCmd.ExecuteScalar(); if (count == 1) { isValid = true; } } } return isValid; } public void CreateUser(User newUser) { using (SqlConnection sqlCnn = new SqlConnection(ConfigurationManager.ConnectionStrings["MusicLibraryConnectionString"].ConnectionString)) { sqlCnn.Open(); using (SqlCommand sqlCmd = new SqlCommand(String.Format("INSERT INTO [Users] (user_firstName, user_lastName, user_emailAddress, user_password, user_accessCode) VALUES ('{0}', '{1}', '{2}', '{3}', '{4}');", newUser.FirstName, newUser.LastName, newUser.EmailAddress, newUser.Password, newUser.AccessCode), sqlCnn)) { sqlCmd.ExecuteNonQuery(); } } DeleteAccessCode(newUser.AccessCode); } public void DeleteAccessCode(string accessCode) { using (SqlConnection sqlCnn = new SqlConnection(ConfigurationManager.ConnectionStrings["MusicLibraryConnectionString"].ConnectionString)) { sqlCnn.Open(); using (SqlCommand sqlCmd = new SqlCommand(String.Format("DELETE FROM [AccessCodes] WHERE [accessCode_accessCode] = '{0}';", accessCode), sqlCnn)) { sqlCmd.ExecuteNonQuery(); } } } } </code></pre>
 

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