/*15.6
(文件浏览器)以图15.14、图15.28 和图15.31中的程序为基础,创建一个( 类似于Windows Explorer 的文件浏览器。这个文件浏览器应具有TreeView,它使用户能够浏览文件夹。还应具有List-View,它用于显示所浏览文件夹的内容( 全部子文件夹和文件)。在ListView 中双击文件应能打开它; 在ListView或TreeView 中双击文件夹应能浏览它。如果由于权限设置使文件或文件夹无法访问,则应通知用户。
*/
using System;
using System.Drawing;
using System.Windows.Forms;
using System.IO;
namespace Explorer
{
   public partial class ExplorerForm : Form
   {
      private string directory;
      public ExplorerForm()
      {
         InitializeComponent();
      }
      public void PopulateTreeView(
         string directoryValue, TreeNode parentNode )
      {
         string[] directoryArray =
            Directory.GetDirectories( directoryValue );
         try
         {
            if ( directoryArray.Length != 0 )
            {
               foreach ( var directory in directoryArray )
               {
                  TreeNode myNode = new TreeNode( directory );
                  parentNode.Nodes.Add( myNode );
                  PopulateTreeView( directory, myNode );
               } 
            } 
         } 
         catch ( UnauthorizedAccessException )
         {
            parentNode.Nodes.Add( "Access denied" );
         }
      } 
      private void ExplorerForm_Load( object sender, EventArgs e )
      {
         Image folderImage = Properties.Resources.folder;
         Image fileImage = Properties.Resources.file;
         fileFolder.Images.Add( folderImage );
         fileFolder.Images.Add( fileImage );
         directoryTreeView.Nodes.Add( "C:" );
         PopulateTreeView( @"C:\", directoryTreeView.Nodes[0] );
      }
      private void directoryTreeView_AfterSelect(
         object sender, TreeViewEventArgs e )
      {
         TreeNode tempNode = directoryTreeView.SelectedNode;
         if ( directoryTreeView.SelectedNode.Text == "C:" )
            directory = directoryTreeView.SelectedNode.Text + @"\";
         else
            directory = directoryTreeView.SelectedNode.Text;
         LoadFilesInDirectory( directory );
      } 
      public void LoadFilesInDirectory( string currentDirectory )
      {
         DirectoryInfo DIcurrent;
         DirectoryInfo[] DIArray;
         FileInfo[] FIArray;
         ListViewItem newDirectoryItem;
         ListViewItem newFileItem;
         try
         {
            browserListView.Items.Clear();
            directory = currentDirectory;
            DIcurrent = new DirectoryInfo( directory );
            DIArray = DIcurrent.GetDirectories();
            FIArray = DIcurrent.GetFiles();
            foreach ( var directoryInformation in DIArray )
            {
               newDirectoryItem = browserListView.Items.Add(
                  directoryInformation.Name );
               newDirectoryItem.ImageIndex = 0;
            } 
            foreach ( var fileInformation in FIArray )
            {
               newFileItem =
                  browserListView.Items.Add( fileInformation.Name );
               newFileItem.ImageIndex = 1;
            } 
         }
         catch ( UnauthorizedAccessException )
         {
            MessageBox.Show( "Warning: Some files may not be " +
               "visible due to permission settings", "Attention",
               MessageBoxButtons.OK, MessageBoxIcon.Warning );
         } 
      } 
      private void browserListView_DoubleClick(
         object sender, EventArgs e )
      {
         string chosen;
         if ( browserListView.SelectedItems.Count != 0 )
         {
            chosen = browserListView.SelectedItems[0].Text;
            System.Diagnostics.Process.Start( directory + "\\" +
               browserListView.SelectedItems[0].Text );
         } 
      } 
   } 
}