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://webabcd.blog.51cto.com/1787395/342779 


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, FileMode.Open, 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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