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Ich habe gerade angefangen in C# zu programmieren und habe gelesen, dass das Teilen Ihrer Anwendung/Website in die drei verschiedenen Schichten die beste Praxis ist, aber es fällt mir schwer zu verstehen, wie. Ich arbeite an einem Haustier-Projekt, um mehr über C# zu lehnen, aber ich möchte keine schlechten Angewohnheiten anfangen. Kannst du schauen, was ich habe und sehen, ob ich das richtig mache? Bieten Sie einige Tipps an, wie Sie alles auf die verschiedenen Ebenen aufteilen können?Präsentation, Business und Data Layer
Presentation Layer
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Project: Ruth</title>
<link href="CSS/StyleSheet.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<div class="Body">
<div class="Header">
<div class="Nav">
<img src="images/Header_Main.gif" alt="" width="217" height="101" />
<div class="Menu">
<a href="Default.aspx">
<img src="images/Header_Home-Off.gif" alt="" /></a>
<a href="Default.aspx">
<img src="images/Header_About-Off.gif" alt="" /></a>
<a href="Register.aspx">
<img src="images/Header_Register-Off.gif" alt="" /></a>
<a href="Default.aspx">
<img src="images/Header_Credits-Off.gif" alt="" /></a>
</div>
</div>
</div>
<div class="Content">
<div class="CurrentlyListening">
<asp:Label ID="lblCurrentListen" runat="server" Text="(Nothing Now)" CssClass="Txt"></asp:Label>
</div>
<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">
<RowStyle CssClass="RowStyle" />
<AlternatingRowStyle CssClass="AltRowStyle" />
<HeaderStyle CssClass="HeaderStyle" />
<Columns>
<asp:BoundField DataField="artist_name" HeaderText="Artist" SortExpression="artist_name" HeaderStyle-Width="200" />
<asp:BoundField DataField="album_title" HeaderText="Album" SortExpression="album_title" HeaderStyle-Width="200" />
<asp:BoundField DataField="song_title" HeaderText="Track" SortExpression="song_title" HeaderStyle-Width="200" />
<asp:TemplateField HeaderText="DL">
<ItemTemplate>
<a href="http://####/Proj_Ruth/Data/<%# Eval("file_path") %>" class="lnk">Link</a>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="sdsLibrary" runat="server" ConnectionString="<%$ ConnectionStrings:MusicLibraryConnectionString %>" 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="<%$ ConnectionStrings:MusicLibraryConnectionString.ProviderName %>" 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">
<DeleteParameters>
<asp:Parameter Name="lib_id" Type="Int32" />
</DeleteParameters>
<InsertParameters>
<asp:Parameter Name="artist_name" Type="String" />
<asp:Parameter Name="album_title" Type="String" />
<asp:Parameter Name="song_title" Type="String" />
<asp:Parameter Name="file_path" Type="String" />
</InsertParameters>
<UpdateParameters>
<asp:Parameter Name="artist_name" Type="String" />
<asp:Parameter Name="album_title" Type="String" />
<asp:Parameter Name="song_title" Type="String" />
<asp:Parameter Name="file_path" Type="String" />
<asp:Parameter Name="lib_id" Type="Int32" />
</UpdateParameters>
</asp:SqlDataSource>
</div>
</div>
</form>
</body>
</html>
Business Layer
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);
}
}
}
Data Access Layer (DAL)
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();
}
}
}
}
Off Thema vielleicht, aber muss ich die Verbindung in meinem Beispiel in der DAL schließen? –
Wie bewerten Sie meinen aktuellen Code oben? –
@Jon: Sie müssen * es * nicht explizit schließen, da Sie ein "using construct" verwenden, das die Verbindung abschafft. Das heißt, Sie sollten es wahrscheinlich noch für Klarheit schließen. – Cerebrus