稳扎稳打Silverlight(16) - 2.0数据之独立存储(Isolated Storage)

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稳扎稳打Silverlight(16) - 2.0数据之独立存储(Isolated Storage)

作者： webabcd


介绍
Silverlight 2.0 数据的独立存储(Isolated Storage)：
    IsolatedStorageFile - 操作 独立存储 的类
        IsolatedStorageFile.GetUserStoreForSite() - 按站点获取用户的独立存储
        IsolatedStorageFile.GetUserStoreForApplication() - 按应用程序获取用户的独立存储
    IsolatedStorageSettings - 在独立存储中保存的 key-value 字典表
        IsolatedStorageSettings.SiteSettings - 按站点保存的 key-value 字典表
        IsolatedStorageSettings.ApplicationSettings - 按应用程序保存的 key-value 字典表


在线DEMO
http://www.voidcn.com/article/p-ounmxjds-tq.html  


示例
IsolatedStorage.xaml

<UserControl x:Class="Silverlight20.Data.IsolatedStorage"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
        <StackPanel HorizontalAlignment="Left">
                <TextBox x:Name="txtMsg" Margin="5" />
                <TextBox x:Name="txtMsg2" Margin="5" />
                <Button x:Name="increase" Content="增加配额" Click="increase_Click" Margin="5" />
        </StackPanel>
</UserControl>

 

IsolatedStorage.xaml.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using System.IO.IsolatedStorage;

using System.IO;

namespace Silverlight20.Data

{

         public partial class IsolatedStorage : UserControl

        {

                 public IsolatedStorage()

                {

                        InitializeComponent();

                         // 演示 IsolatedStorageFile

                        Demo();

                         // 演示 IsolatedStorageSettings

                        Demo2();

                }

                 /// <summary>

                 /// 演示 IsolatedStorageFile

                 /// </summary>

                 void Demo()

                {

                         // Isolated Storage - 独立存储。一个虚拟文件系统

                         // IsolatedStorageFile - 操作 独立存储 的类

                         //         IsolatedStorageFile.GetUserStoreForSite() - 按站点获取用户的独立存储

                         //         IsolatedStorageFile.GetUserStoreForApplication() - 按应用程序获取用户的独立存储

                        

                         // using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForSite())

                         using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())

                        {

                                 // DirectoryExists(path) - 指定的路径是否存在

                                 // CreateDirectory(path) - 创建指定的路径

                                 // FileExists(path) - 指定的文件是否存在

                                 // CreateFile(path) - 创建指定的文件

                                 // GetDirectoryNames() - 获取根目录下的目录名数组

                                 // GetFileNames()() - 获取根目录下的文件名数组

                                 // GetDirectoryNames(path) - 获取指定目录下的目录名数组

                                 // GetFileNames(path) - 获取指定目录下的文件名数组

                                 // OpenFile() - 打开指定的文件。具体参数参看文档

                                 // DeleteFile(path) - 删除指定的文件

                                 // DeleteDirectory(path) - 删除指定的目录（要求目录存在，且目录内无内容）

                                 // Remove() - 关闭 IsolatedStorageFile 对象并移除独立存储内的全部内容

                                 // 在根目录下创建指定的目录

                                 if (!isf.DirectoryExists( "Directory01"))

                                        isf.CreateDirectory( "Directory01");

                                 if (!isf.DirectoryExists( "Directory02"))

                                        isf.CreateDirectory( "Directory02");

                                 // 创建指定的子目录

                                 string subdirectory01 = System.IO.Path.Combine( "Directory01","subdirectory01");

                                 string subdirectory02 = System.IO.Path.Combine( "Directory01","subdirectory02");

                                 if (!isf.DirectoryExists(subdirectory01))

                                        isf.CreateDirectory(subdirectory01);

                                 if (!isf.DirectoryExists(subdirectory02))

                                        isf.CreateDirectory(subdirectory02);

                                

                                 // 根目录下创建指定的文件

                                 if (!isf.FileExists( "RootFile.txt"))

                                {

                                        IsolatedStorageFileStream isfs = isf.CreateFile( "RootFile01.txt");

                                        isfs.Close();

                                }

                                 // 在指定的目录下创建指定的文件

                                 string file01 = System.IO.Path.Combine(subdirectory01,"File01.txt");

                                 string file02 = System.IO.Path.Combine(subdirectory01,"File02.txt");

                                 string file03 = System.IO.Path.Combine(subdirectory01,"File03.xml");

                                 if (!isf.FileExists(file01))

                                {

                                         // IsolatedStorageFileStream - 独立存储内的文件流。继承自 FileStream

                                        IsolatedStorageFileStream isfs = isf.CreateFile(file01);

                                        isfs.Close();

                                }

                                 if (!isf.FileExists(file02))

                                {

                                        IsolatedStorageFileStream isfs = isf.CreateFile(file02);

                                        isfs.Close();

                                }

                                 if (!isf.FileExists(file03))

                                {

                                        IsolatedStorageFileStream isfs = isf.CreateFile(file03);

                                        isfs.Close();

                                }

                                txtMsg.Text += "根目录下的目录列表：\r\n";

                                 // 获取根目录下的目录名数组

                                 foreach ( string directoryName in isf.GetDirectoryNames())

                                {

                                        txtMsg.Text += directoryName + "\r\n";

                                }

                                txtMsg.Text += "根目录下的文件列表：\r\n";

                                 // 获取根目录下的文件名数组

                                 foreach ( string fileName in isf.GetFileNames())

                                {

                                        txtMsg.Text += fileName + "\r\n";

                                }

                                txtMsg.Text += "目录 Directory01 下的目录列表：\r\n";

                                 // 获取 Directory01 目录下的目录名数组

                                 foreach ( string directoryName in isf.GetDirectoryNames(subdirectory01))

                                {

                                        txtMsg.Text += directoryName + "\r\n";

                                }

                                txtMsg.Text += "目录 Directory01/subdirectory01 下的*.txt文件列表：\r\n";

                                 // 获取 Directory01/subdirectory01 目录下的后缀名为 txt 的文件名数组

                                 foreach ( string fileName in isf.GetFileNames(System.IO.Path.Combine(subdirectory01,"*.txt")))

                                {

                                        txtMsg.Text += fileName + "\r\n";

                                }

                                 if (isf.FileExists(file01))

                                {

                                         // 在文件 file01 中写入内容

                                        IsolatedStorageFileStream streamWrite = isf.OpenFile(file01,FileMode.Open,FileAccess.Write);

                                         using (StreamWriter sw = new StreamWriter(streamWrite))

                                        {

                                                sw.WriteLine( "我是：webabcd");

                                                sw.WriteLine( "我专注于asp.net,Silverlight");

                                        }

                                        txtMsg.Text += "文件 File01.txt 的内容：\r\n";

                                         // 读取文件 file01 中的内容

                                        IsolatedStorageFileStream streamRead = isf.OpenFile(file01,FileAccess.Read);

                                         using (StreamReader sr = new StreamReader(streamRead))

                                        {

                                                txtMsg.Text += sr.ReadToEnd();

                                        }

                                }

                                 // 删除文件 file01

                                 if (isf.FileExists(file01))

                                {

                                        isf.DeleteFile(file01);

                                }

                                 try

                                {

                                         // 删除目录 subdirectory01

                                        isf.DeleteDirectory(subdirectory01);

                                }

                                 catch (IsolatedStorageException ex)

                                {

                                         // IsolatedStorageException - 操作临时存储失败时抛出的异常

                                         // 因为 subdirectory01 目录内还有文件，所以会抛异常

                                        txtMsg.Text += ex.Message;

                                }

                        }

                }

                 /// <summary>

                 /// 演示 IsolatedStorageSettings

                 /// </summary>

                 void Demo2()

                {

                         // IsolatedStorageSettings - 在独立存储中保存的 key-value 字典表

                         //         IsolatedStorageSettings.SiteSettings - 按站点保存的 key-value 字典表

                         //         IsolatedStorageSettings.ApplicationSettings - 按应用程序保存的 key-value 字典表

                        IsolatedStorageSettings iss = IsolatedStorageSettings.ApplicationSettings;

                         // Add(key,value) - 添加一对 key-value

                        iss.Add( "key","value");

                        txtMsg2.Text += ( string)iss[ "key"] + "\r\n";

                         // 修改指定的 key 的 value

                        iss[ "key"] = "value2";

                        txtMsg2.Text += ( string)iss[ "key"] + "\r\n";

                         // Remove(key) - 移除指定的 key

                         // Count - 字典表内的总的 key-value 数

                        iss.Remove( "key");

                        txtMsg2.Text += iss.Count;

                }

                

                 private void increase_Click( object sender,RoutedEventArgs e)

                {

                         // 演示独立存储的配额的相关操作

                         using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())

                        {

                                 // Quota - 当前配额（KB）

                                 // IncreaseQuotaTo(newQuotaSize) - 增加到指定的配额

                                 // AvailableFreeSpace - 当前的可用配额

                                isf.IncreaseQuotaTo(isf.Quota + 1 * 1024 * 1024);

                                System.Windows.browser.HtmlPage.Window.Alert(

                                         string.Format( "当前配额：{0}；可用配额：{1}",isf.Quota,isf.AvailableFreeSpace));

                        }

                }    

        }

}

 

 

演示 IsolatedStorageFile 的运行结果：
根目录下的目录列表：
Directory01
Directory02
根目录下的文件列表：
RootFile01.txt
__LocalSettings
目录 Directory01 下的目录列表：
subdirectory01
目录 Directory01/subdirectory01 下的*.txt文件列表：
File01.txt
File02.txt
文件 File01.txt 的内容：
我是：webabcd
我专注于asp.net,Silverlight
无法删除，目录不为空或不存在。

演示 IsolatedStorageSettings 的运行结果：
value
value2
0


OK
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