XmlSerializer的序列化就是把一个对象的public属性（有Get和Set）和public字段保存到一个xml文件，反序列化就是从一个xml文件得到一个特定的类的实例对象。
Classifieds的程序里面的一些设置就是用序列化技术保存在xml文件里面的。这个类就是 SiteSettings。
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Text;
using System.Xml.Serialization;
using AspNet.StarterKits.Classifieds.Web;
namespace AspNet.StarterKits.Classifieds.BusinessLogicLayer
{
/// <summary>
/// Contains the implementation for the site settings.
/// </summary>
public class SiteSettings
{
private const string XmlConfigFile = "~/App_Data/site-config.xml";
private int _maxPhotosPerAd;
private bool _storePhotosInDatabase;
private string _serverPhotoUploadDirectory;
private bool _adApprovalRequired;
private bool _allowUsersToEditAds;
private bool _allowUsersToDeleteAdsInDB;
private int _maxAdRunningDays;
private AdminNotificationSetting _adminNotification;
private string _siteName;
private string _siteEmail;
public bool AllowImageUploads
{
get
{
return (_maxPhotosPerAd > 0);
}
}
public int MaxPhotosPerAd
{
get
{
return _maxPhotosPerAd;
}
set
{
lock (this)
{
_maxPhotosPerAd = value;
}
}
}
public bool StorePhotosInDatabase
{
get
{
return _storePhotosInDatabase;
}
set
{
lock (this)
{
_storePhotosInDatabase = value;
}
}
}
public string ServerPhotoUploadDirectory
{
get
{
return _serverPhotoUploadDirectory;
}
set
{
lock (this)
{
_serverPhotoUploadDirectory = value;
}
}
}
public bool AdActivationRequired
{
get
{
return _adApprovalRequired;
}
set
{
lock (this)
{
_adApprovalRequired = value;
}
}
}
public bool AllowUsersToEditAds
{
get
{
return _allowUsersToEditAds;
}
set
{
lock (this)
{
_allowUsersToEditAds = value;
}
}
}
public bool AllowUsersToDeleteAdsInDB
{
get
{
return _allowUsersToDeleteAdsInDB;
}
set
{
lock (this)
{
_allowUsersToDeleteAdsInDB = value;
}
}
}
public int MaxAdRunningDays
{
get
{
return _maxAdRunningDays;
}
set
{
lock (this)
{
_maxAdRunningDays = value;
}
}
}
[System.ComponentModel.TypeConverter(typeof(System.ComponentModel.EnumConverter))]
public AdminNotificationSetting AdminNotification
{
get
{
return _adminNotification;
}
set
{
lock (this)
{
_adminNotification = value;
}
}
}
public string SiteName
{
get
{
return _siteName;
}
set
{
lock (this)
{
_siteName = value;
}
}
}
public string SiteEmailAddress
{
get
{
return _siteEmail;
}
set
{
lock (this)
{
_siteEmail = value;
}
}
}
public string SiteEmailFromField
{
get
{
return String.Format("{0} <{1}>", _siteName, _siteEmail);
}
}
public static SiteSettings LoadFromConfiguration()
{
SiteSettings s = LoadFromXml();
if (s == null)
{
s = new SiteSettings();
s.MaxPhotosPerAd = 5;
s.StorePhotosInDatabase = true;
s.ServerPhotoUploadDirectory = "Upload";
s.AdActivationRequired = false;
s.AllowUsersToEditAds = true;
s.AllowUsersToDeleteAdsInDB = true;
s.MaxAdRunningDays = 21;
s.AdminNotification = AdminNotificationSetting.None;
s.SiteName = "ASP.NET Classifieds";
s.SiteEmailAddress = "classifieds@yoursite.com";
SaveToXml(s);
}
return s;
}
public static SiteSettings GetSharedSettings()
{
return ClassifiedsHttpApplication.ClassifiedsApplicationSettings;
}
public static bool UpdateSettings(SiteSettings newSettings)
{
// write settings to code or db
// update Application-wide settings, only over-writing settings that users should edit
lock (ClassifiedsHttpApplication.ClassifiedsApplicationSettings)
{
// Ads must be activated before appearing on the site
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.AdActivationRequired = newSettings.AdActivationRequired;
// Store Photos in Database
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.StorePhotosInDatabase = newSettings.StorePhotosInDatabase;
// ... else: use the following directory to save uploaded Photos:
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.ServerPhotoUploadDirectory = newSettings.ServerPhotoUploadDirectory;
// Maximum Number of Photos to Upload
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.MaxPhotosPerAd = newSettings.MaxPhotosPerAd;
// Maximum Number of Days for which an Ad is active
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.MaxAdRunningDays = newSettings.MaxAdRunningDays;
// Allow Users to edit their own Ads
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.AllowUsersToEditAds = newSettings.AllowUsersToEditAds;
// Users to delete ads direclty in the database
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.AllowUsersToDeleteAdsInDB = newSettings.AllowUsersToDeleteAdsInDB;
// Notifications to Administrators
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.AdminNotification = newSettings.AdminNotification;
// Site Name
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.SiteName = newSettings.SiteName;
// Contact Email Address for Site
ClassifiedsHttpApplication.ClassifiedsApplicationSettings.SiteEmailAddress = newSettings.SiteEmailAddress;
// Serialize to Xml Config File
return SaveToXml(ClassifiedsHttpApplication.ClassifiedsApplicationSettings);
}
}
private static SiteSettings LoadFromXml()
{
SiteSettings settings = null;
HttpContext context = HttpContext.Current;
if (context != null)
{
string configPath = context.Server.MapPath(XmlConfigFile);
XmlSerializer xml = null;
FileStream fs = null;
bool success = false;
int numAttempts = 0;
while (!success && numAttempts < 2)
{
try
{
numAttempts++;
xml = new XmlSerializer(typeof(SiteSettings));
fs = new FileStream(configPath, System.IO.FileMode.Open, System.IO.FileAccess.Read);
settings = xml.Deserialize(fs) as SiteSettings;
success = true;
}
catch (Exception x)
{
// if an exception is thrown, there might have been a sharing violation;
// we wait and try again (max: two attempts)
success = false;
System.Threading.Thread.Sleep(1000);
if (numAttempts == 2)
throw new Exception("The Site Configuration could not be loaded.", x);
}
}
if (fs != null)
fs.Close();
}
return settings;
}
public string GetXml()
{
StringBuilder result = new StringBuilder();
StringWriter s = new StringWriter(result);
try
{
XmlSerializer xml = new XmlSerializer(typeof(SiteSettings));
xml.Serialize(s, this);
}
finally
{
s.Close();
}
return result.ToString();
}
private static bool SaveToXml(SiteSettings settings)
{
if (settings == null)
return false;
HttpContext context = HttpContext.Current;
if (context == null)
return false;
string configPath = context.Server.MapPath(XmlConfigFile);
XmlSerializer xml = null;
System.IO.FileStream fs = null;
bool success = false;
int numAttempts = 0;
while (!success && numAttempts < 2)
{
try
{
numAttempts++;
xml = new XmlSerializer(typeof(SiteSettings));
fs = new FileStream(configPath, FileMode.Create, FileAccess.ReadWrite, FileShare.None);
xml.Serialize(fs, settings);
success = true;
}
catch
{
// if an exception is thrown, there might have been a sharing violation;
// we wait and try again (max: two attempts)
success = false;
System.Threading.Thread.Sleep(1000);
}
}
if (fs != null)
fs.Close();
return success;
}
}
}
