Silverlight实用窍门系列：49.Silverlight中管理独立存储--Isolated Storage【附带实例源码】

网站+用户+应用程序定位一个独立存储，也就是说必须得相同网站，相同用户，相同应用程序才能够访问这个独立的存储空间。独立存储是IsolatedStorageFile密封类来进行设置的，这个类分布在命名空间System.IO.IsolatedStorag。我们引用System.IO命名空间对文件进行操作。下面我们来看一个演示的Xaml代码如下：

<Grid x:Name="LayoutRoot" Background="White">
 <Button Content="设置独立存储" Height="23" HorizontalAlignment="Left" Margin="29,79,0,0"
 Name="btnSetStorage" VerticalAlignment="Top" Width="75" Click="btnSetStorage_Click" />
 <Button Content="清空独立存储" Height="23" HorizontalAlignment="Left" Margin="268,79,0,0"
 Name="btnClearStorage" VerticalAlignment="Top" Width="75" Click="btnClearStorage_Click" />
 <Button Content="获取独立存储列表" Height="23" HorizontalAlignment="Left" Margin="142,79,0,0"
 Name="btnGetStorage" VerticalAlignment="Top" Width="107" Click="btnGetStorage_Click" />
 <ListBox Height="165" HorizontalAlignment="Left" Margin="12,123,0,0" Name="listBox1"
 VerticalAlignment="Top" Width="166" />
 <ListBox Height="165" HorizontalAlignment="Left" Margin="198,123,0,0" Name="listBox2" 
 VerticalAlignment="Top" Width="166" />
 <Button Content="读取" Height="23" HorizontalAlignment="Left" Margin="365,79,0,0" 
 Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
 <sdk:Label Height="28" HorizontalAlignment="Left" Margin="370,123,0,0" Name="label1"
 VerticalAlignment="Top" Width="189" />
 <sdk:Label Height="28" HorizontalAlignment="Left" Margin="370,181,0,0" Name="label2" 
 VerticalAlignment="Top" Width="189" />
 </Grid>

public partial class MainPage : UserControl
{
 public MainPage()
 {
 InitializeComponent();
 }
 private void btnSetStorage_Click(object sender, RoutedEventArgs e)
 {
 using (var storage = IsolatedStorageFile.GetUserStoreForApplication())
 { 
 //创建First父目录
 if(!storage.DirectoryExists("FatherFirstDir"))
 {
 storage.CreateDirectory("FatherFirstDir");
 
 //创建子目录
 string SonDir = Path.Combine("FatherFirstDir", "SonFirstDir");
 storage.CreateDirectory(SonDir);

 //创建文件
 IsolatedStorageFileStream fileStream = storage.CreateFile(Path.Combine(SonDir, "First.txt"));
 using (StreamWriter swriter = new StreamWriter(fileStream))
 {
 swriter.Write("这是第一个程序txt");
 }
 fileStream.Close();
 }

 //创建Secend父目录
 if (!storage.DirectoryExists("FatherSecendDir"))
 {
 storage.CreateDirectory("FatherSecendDir");
 //在一级目录下添加一个文件
 IsolatedStorageFileStream fileStream = storage.CreateFile(Path.Combine("FatherSecendDir", "second.txt"));
 using (StreamWriter swriter = new StreamWriter(fileStream))
 {
 swriter.Write("新的txt程序");
 }
 fileStream.Close();
 }

 //当前的独立存储状态
 this.label1.Content = "最大空间量：" + storage.Quota + " 已使用量:" + storage.UsedSize;
 //获取文件First.txt的值
 using (StreamReader reader = new StreamReader(storage.OpenFile("FatherFirstDir\\SonFirstDir\\First.txt",
 FileMode.Open, FileAccess.Read)))
 {
 this.label2.Content = reader.ReadToEnd();
 }

 }
 }

 private void btnGetStorage_Click(object sender, RoutedEventArgs e)
 {
 //获取文件夹中的文件以及所有的文件夹名称
 using (var storage = IsolatedStorageFile.GetUserStoreForApplication())
 {
 if (storage.DirectoryExists("FatherSecendDir"))
 {
 String[] fileList = storage.GetFileNames("FatherSecendDir/");
 this.listBox1.ItemsSource = fileList;

 String[] dirList = storage.GetDirectoryNames("*");
 this.listBox2.ItemsSource = dirList;
 }
 }
 }

 private void btnClearStorage_Click(object sender, RoutedEventArgs e)
 {
 //删除所有的文件以及文件夹
 using (var storage = IsolatedStorageFile.GetUserStoreForApplication())
 {
 //在这里简单做一个判断，实际应用过程中不可
 if (storage.FileExists("FatherFirstDir\\SonFirstDir\\First.txt"))
 {
 storage.DeleteFile("FatherFirstDir\\SonFirstDir\\First.txt");
 storage.DeleteDirectory("FatherFirstDir\\SonFirstDir");
 storage.DeleteDirectory("FatherFirstDir");
 storage.DeleteFile("FatherSecendDir\\second.txt");
 storage.DeleteDirectory("FatherSecendDir");
 }
 }
 }

 private void button1_Click(object sender, RoutedEventArgs e)
 {
 int addSpaceSize = 2097152;
 //增加最大独立存储空间量
 using (var storage = IsolatedStorageFile.GetUserStoreForApplication())
 {
 if (storage.AvailableFreeSpace < addSpaceSize)
 {
 storage.IncreaseQuotaTo(storage.Quota+ addSpaceSize);
 }
 this.label1.Content = "最大空间量：" + storage.Quota + " 已使用量:" + storage.UsedSize;
 }

 }
}

最后我们看看运行效果如下，如需源码请点击 SLStorage.zip 下载。