详解Silverlight 2中的独立存储（Isolated Storage）

下面来看各个功能的实现：

创建目录，直接使用CreateDirectory方法就可以了，另外还可以使用DirectoryExistes方法来判断目录是否已经存在：

void btnCreateDirectory_Click(object sender, RoutedEventArgs e)
{
    using (IsolatedStorageFile store =
                    IsolatedStorageFile.GetUserStoreForApplication())
    {
        String directoryName = this.txtDirectoryName.Text;
        if (this.lstDirectories.SelectedItem != null)
        {
            directoryName = System.IO.Path.Combine(this.lstDirectories.SelectedItem.ToString(),
                            directoryName);
        }

        if (!store.DirectoryExists(directoryName))
        {
            store.CreateDirectory(directoryName);
            HtmlPage.Window.Alert("创建目录成功！");
        }
    }
}

创建文件，通过CreateFile方法来获取一个IsolatedStorageFileStream，并将内容写入到文件中：

void btnCreateFile_Click(object sender, RoutedEventArgs e)
{
    if (this.lstDirectories.SelectedItem == null &&
        this.txtDirectoryName.Text == "")
    {
        HtmlPage.Window.Alert("请先选择一个目录或者输入目录名");
        return;
    }
    using (IsolatedStorageFile store =
                       IsolatedStorageFile.GetUserStoreForApplication())
    {
        String filePath;
        if (this.lstDirectories.SelectedItem == null)
        {
            filePath = System.IO.Path.Combine(this.txtDirectoryName.Text,
                            this.txtFileName.Text + ".txt");
        }
        else
        {
            filePath = System.IO.Path.Combine(this.lstDirectories.SelectedItem.ToString(),
                            this.txtFileName.Text + ".txt");
        }
        
        IsolatedStorageFileStream fileStream = store.CreateFile(filePath);
        using (StreamWriter sw = new StreamWriter(fileStream))
        {
            sw.WriteLine(this.txtFileContent.Text);
        }
        fileStream.Close();
        HtmlPage.Window.Alert("写入文件成功！");
    }
}

读取文件，直接使用System.IO命名空间下的StreamReader：

void btnReadFile_Click(object sender, RoutedEventArgs e)
{
    if (this.lstDirectories.SelectedItem == null ||
        this.lstFiles.SelectedItem == null)
    {
        HtmlPage.Window.Alert("请先选择目录和文件！");
        return;
    }
    using (IsolatedStorageFile store =
                       IsolatedStorageFile.GetUserStoreForApplication())
    {
        String filePath = System.IO.Path.Combine(this.lstDirectories.SelectedItem.ToString(),
                          this.lstFiles.SelectedItem.ToString());
        if (store.FileExists(filePath))
        {
            StreamReader reader = new StreamReader(store.OpenFile(filePath,
                   FileMode.Open, FileAccess.Read));
            this.txtFileContent.Text = reader.ReadToEnd();

            this.txtDirectoryName.Text = this.lstDirectories.SelectedItem.ToString();
            this.txtFileName.Text = this.lstFiles.SelectedItem.ToString();
        }
    }
}