修炼九阴真经Windows Phone开发 (8)：独立存储Isolated storage

前台XAML

<phone:PhoneApplicationPage
x:Class="IsolatedStorageApp.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
SupportedOrientations="Portrait" Orientation="Portrait"
shell:SystemTray.IsVisible="True">

<!--LayoutRoot is the root grid where all page content is placed-->
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>

<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock x:Name="ApplicationTitle" Text="ISOLATED STORAGE" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock x:Name="PageTitle" Text="独立存储" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>

<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<TextBox Height="72" HorizontalAlignment="Left" Margin="-1,42,0,0" Name="txtWrite" Text="" VerticalAlignment="Top" Width="416" />
<Button Content="保存" Height="72" HorizontalAlignment="Left" Margin="-1,160,0,0" Name="btnWrite" VerticalAlignment="Top" Width="160" Click="txtWrite_Click" />
<TextBlock Height="149" HorizontalAlignment="Left" Margin="12,275,0,0" Name="txtRead" Text="" VerticalAlignment="Top" Width="403" />
<Button Content="读取" Height="72" HorizontalAlignment="Left" Margin="-1,450,0,0" Name="btnRead" VerticalAlignment="Top" Width="160" Click="btnRead_Click" />
</Grid>
</Grid>

<!--Sample code showing usage of ApplicationBar-->
<!--<phone:PhoneApplicationPage.ApplicationBar>
<shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
<shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>
<shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>
<shell:ApplicationBar.MenuItems>
<shell:ApplicationBarMenuItem Text="MenuItem 1"/>
<shell:ApplicationBarMenuItem Text="MenuItem 2"/>
</shell:ApplicationBar.MenuItems>
</shell:ApplicationBar>
</phone:PhoneApplicationPage.ApplicationBar>-->

</phone:PhoneApplicationPage>

后台 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 Microsoft.Phone.Controls;
using System.IO;
using System.IO.IsolatedStorage;

namespace IsolatedStorageApp
{
public partial class MainPage : PhoneApplicationPage
{
// Constructor
public MainPage()
{
InitializeComponent();
}

private void txtWrite_Click(object sender, RoutedEventArgs e)
{
//Obtain the virtual store for application
IsolatedStorageFile myStore = IsolatedStorageFile.GetUserStoreForApplication();

//Create a new folder and call it "FavorFolder"
myStore.CreateDirectory("FavorFolder");

//Create a new file and assign a StreamWriter to the store and this new file (myFile.txt)
//Also take the text contents from the txtWrite control and write it to myFile.txt

StreamWriter writeFile = new StreamWriter(new IsolatedStorageFileStream("FavorFolder\\myFile.txt", FileMode.OpenOrCreate, myStore));
writeFile.WriteLine(txtWrite.Text);
writeFile.Close();
}

private void btnRead_Click(object sender, RoutedEventArgs e)
{
//Obtain a virtual store for application
IsolatedStorageFile myStore = IsolatedStorageFile.GetUserStoreForApplication();

//This code will open and read the contents of myFile.txt
//Add exception in case the user attempts to click Read button first.

StreamReader readFile = null;

try
{
readFile = new StreamReader(new IsolatedStorageFileStream("FavorFolder\\myFile.txt", FileMode.Open, myStore));
string fileText = readFile.ReadLine();

//The control txtRead will display the text entered in the file
txtRead.Text = fileText;
readFile.Close();
}
catch
{
txtRead.Text = "Need to create directory and the file first.";
}
}
}
}

总结：如果是保存临时数据(一次执行周期之间的数据)最好使用PhoneApplicationService类保存;如果是保存应用程序设置(多次执行周期之间保存数据)最好使用独立存储IsolatedStorageSettings类保存。