本地（客户端）数据存储
通过使用独立存储，数据将始终按用户在虚拟文件系统中隔离，虚拟文件系统可以是根目录中的一个文件，也可以是一个目录和文件树。
独立存储数据舱是一个抽象的存储位置，而不是一个具体的存储位置。它由一个或多个独立的存储文件（称为存储区）组成，这些存储文件包含存储数据的实际目录位置。任何类型的数据都可以保存到存储区中。
存储区通常驻留在客户端，但应用程序也可以使用服务器上的独立存储。
SDK没有说文件存储的地方，搜索一下发现存在于类似以下目录的地方：
C:"Documents and Settings"Administrator.WANGXIN.000"Local Settings"Application Data"Microsoft"Silverlight"is"fonkhtyt.ues"gdnfncxm.pga"1"s"yqvlp0zp0vt53mbuwhvhmrf0h2a0a0viyspfl24d0iwrtdzxevaaafba"f
本地文件操作
public static void Demo(TextBlock outputBlock)
{
// 获取本地存储设置
try
{
using (var store = IsolatedStorageFile.GetUserStoreForApplication())
{
// 使用StringBuilder构造结构.
StringBuilder sb = new StringBuilder();
// 建三个目录.
store.CreateDirectory("MyApp1");
store.CreateDirectory("MyApp2");
store.CreateDirectory("MyApp3");
// 在MyApp1目录下建三个子目录.
string subdirectory1 = Path.Combine("MyApp1", "SubDir1");
string subdirectory2 = Path.Combine("MyApp1", "SubDir2");
string subdirectory3 = Path.Combine("MyApp1", "SubDir3");
store.CreateDirectory(subdirectory1);
store.CreateDirectory(subdirectory2);
store.CreateDirectory(subdirectory3);
// 建新文件.
IsolatedStorageFileStream rootFile = store.CreateFile("InTheRoot.txt");
rootFile.Close();
// 子目录下建新文件.
IsolatedStorageFileStream subDirFile =
store.CreateFile(Path.Combine(subdirectory1, "MyApp1A.txt"));
subDirFile.Close();
// 根目录
string[] directoriesInTheRoot = store.GetDirectoryNames();
string[] filesInTheRoot = store.GetFileNames();
string searchpath = Path.Combine(subdirectory1, "*.*");
string[] filesInSubDirs = store.GetFileNames(searchpath);
// '*' 搜索子目录下文件
string[] subDirectories =
store.GetDirectoryNames(Path.Combine("MyApp1", "*"));
sb.AppendLine("Directories in root:");
foreach (string dir in directoriesInTheRoot)
{
sb.AppendLine(" - " + dir);
}
sb.AppendLine();
sb.AppendLine("Directories under MyApp1:");
foreach (string sDir in subDirectories)
{
sb.AppendLine(" - " + sDir);
}
sb.AppendLine();
sb.AppendLine("Files in the root:");
foreach (string fileName in filesInTheRoot)
{
sb.AppendLine(" - " + fileName);
}
sb.AppendLine();
// List files in MyApp1"SubDir1.
sb.AppendLine(@"Files in MyApp1"SubDir1:");
foreach (string fileName in filesInSubDirs)
{
sb.AppendLine(" - " + fileName);
}
sb.AppendLine();
// 写文件
string filePath = Path.Combine(subdirectory1, "MyApp1A.txt");
if (store.FileExists(filePath))
{
try
{
using (StreamWriter sw =
new StreamWriter(store.OpenFile(filePath,
FileMode.Open, FileAccess.Write)))
{
sw.WriteLine("To do list:");
sw.WriteLine("1. Buy supplies.");
}
}
catch (IsolatedStorageException ex)
{
sb.AppendLine(ex.Message);
}
}
// 读文件
try
{
using (StreamReader reader =
new StreamReader(store.OpenFile(filePath,
FileMode.Open, FileAccess.Read)))
{
string contents = reader.ReadToEnd();
sb.AppendLine(filePath + " contents:");
sb.AppendLine(contents);
}
}
catch (IsolatedStorageException ex)
{
sb.AppendLine(ex.Message);
}
// 删文件.
try
{
if (store.FileExists(filePath))
{
//store.DeleteFile(filePath);
}
}
catch (IsolatedStorageException ex)
{
sb.AppendLine(ex.Message);
}
// 删目录
string dirDelete = Path.Combine("MyApp1", "SubDir3");
try
{
if (store.DirectoryExists(dirDelete))
{
store.DeleteDirectory(dirDelete);
}
}
catch (IsolatedStorageException ex)
{
sb.AppendLine(ex.Message);
}
sb.AppendLine();
// remove the store
store.Remove();
sb.AppendLine("Store removed.");
outputBlock.Text = sb.ToString();
}
}
catch (IsolatedStorageException)
{
// TODO: Handle that store was unable to be accessed.
}
}
}
本地键值字典
下面的示例创建一个使用独立存储的应用程序设置字典，添加键/值对，检索该值，更改该值，然后再删除该值。在 Windows Vista 中，该信息存储在 AppData"LocalLow 目录中。对于其他操作系统版本（包括 Apple Macintosh 上的操作系统）而言，该信息存储在 AppData"Local 目录中。
<StackPanel Height="230" Margin="10" HorizontalAlignment="Left" VerticalAlignment="Top" >
<Button Height="30" Width="60" x:Name="bAdd" Content="Add" Margin="10"
Click="bAdd_Click" ></Button>
<Button Height="30" Width="60" x:Name="bRetrieve" Content="Retrieve" Margin="10"
Click="bRetrieve_Click" ></Button>
<Button Height="30" Width="60" x:Name="bChange" Content="Change" Margin="10"
Click="bChange_Click" ></Button>
<Button Height="30" Width="60" x:Name="bDelete" Content="Delete" Margin="10"
Click="bDelete_Click" ></Button>
</StackPanel>
<TextBox Height="50" Width="280" Background="Beige" x:Name="tbResults"
BorderBrush="Beige" BorderThickness="5"
FontFamily="Arial" FontSize="12" Text="Silverlight Test Area"
HorizontalAlignment="Right"></TextBox>
打开 Page.xaml.cs
private IsolatedStorageSettings appSettings = IsolatedStorageSettings.ApplicationSettings;
private void bAdd_Click(object sender, RoutedEventArgs e)
{
try
{
appSettings.Add("email", "someone@contoso.com");
tbResults.Text = "Settings stored.";
}
catch (ArgumentException ex)
{
tbResults.Text = ex.Message;
}
}
private void bRetrieve_Click(object sender, RoutedEventArgs e)
{
try
{
tbResults.Text = "Setting retrieved: " + (string)appSettings["email"];
}
catch (System.Collections.Generic.KeyNotFoundException ex)
{
tbResults.Text = ex.Message;
}
}
private void bChange_Click(object sender, RoutedEventArgs e)
{
appSettings["email"] = "someone@fabrikam.com";
tbResults.Text = "Changed to: " + (string)appSettings["email"];
}
private void bDelete_Click(object sender, RoutedEventArgs e)
{
appSettings.Remove("email");
tbResults.Text = "Email deleted. Click Retrieve to confirm deletion.";
}