Browsing Via Directories or HTTP, with ASP.NET

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Introduction

This sample project allows users to browse directories via the web. With this code, you can browse these directories via UNC paths or HTTP directory browsing. Example:

• UNC paths - c:\ or \\server\share
• HTTP directory browsing - http://server/directory

Using the code

Create a C# Web Application called Browsing - then drop the files that are in the zip file into that folder. There are 2 helper classes that do all the work that may be removed into their own files and should be applied as a business layer. All the code is kept clean and delineated with #regions.

Explanation of code blocks

Client side JavaScript

The list box I used is really a DIV with a border made to look like a list box. There can be images and text, as well as, any other HTML inside the custom list box - something the regular HTML dropdown does not allow. The two JavaScript functions below are called when a row is single clicked or double clicked.

On a single click, the row is highlighted when the HighLight() method is called. On a double click, the row gets highlighted and sends a request back to the server to update the directories using the DoBrowse() method.

<script language="javascript">
function DoBrowse(obj, objectName, isDirectory)
{
    HighLight(obj, objectName);
    
    if (isDirectory)
    {                
        Form1._actionHidden.value = 'RefreshBrowse';
    }
    else
    {
        Form1._actionHidden.value = 'OpenFile';
    }
    
    Form1._clickedObjectHidden.value = objectName;
    Form1.submit();
}

function HighLight(obj, objectName)
{
    var objs = document.all;
    
    for (var i=0; i<objs.length; i++)
    {
        if (objs[i].className == 'hilite')
        {
            objs[i].className = 'nohilite';
        }
    }
    
    obj.className = 'hilite';
}
</script>

ASP.NET code

On a postback, I want to trigger an action - kind of like an event - but I do not have an event driven object. So I created this _actionHidden.Value that gets set by the JavaScript above and runs through the DoAction() method.

private void Page_Load(object sender, System.EventArgs e)
{
    if(IsPostBack)
        DoAction();
}

private void DoAction()
{
    switch (_actionHidden.Value)
    {
        case "RefreshBrowse" :
            _browseButton_Click(this, null);
            break;
        case "OpenFile" :
            OpenFile();
            break;
    }
    _actionHidden.Value = "";
}

Fills the list box on a postback with my own HTML table:

private void _browseButton_Click(object sender, 
                 System.Web.UI.ImageClickEventArgs e)
{
    if (0 != _browseTextBox.Text.Length)
    {
        UpdateBrowseTextBoxWithSlash();

        _browseTextBox.Text += _clickedObjectHidden.Value;
        _clickedObjectHidden.Value = "";

        FileList fileList = new FileList(_browseTextBox.Text, "*.*");

        Table tb = new Table();
        TableRow tr;
        TableCell td;

        tb.Width = Unit.Percentage(100);
        tb.BorderWidth = 0;
        tb.CellSpacing = 0;
        tb.CellPadding = 4;

        foreach (string directory in fileList.Directories)
        {
            tr = new TableRow();
            td = new TableCell();
            td.Width = Unit.Percentage(100);

            td.CssClass = "nohilite";

            System.Web.UI.WebControls.Image directoryImage = 
                    new System.Web.UI.WebControls.Image();
            directoryImage.ImageUrl = "Images/folder.gif";
            directoryImage.BorderWidth = 0;
            directoryImage.ImageAlign = ImageAlign.AbsMiddle;

            td.Attributes.Add("onDblClick", 
                string.Format("DoBrowse(this, '{0}', 
                true)", directory));
            td.Attributes.Add("onClick", "HighLight(this, '')");

            td.Controls.Add(directoryImage);
            td.Controls.Add(new 
               LiteralControl("<SPAN class='\"text\"'> " 
               + directory + ""));

            tr.Cells.Add(td);
            tb.Rows.Add(tr);
        }

        foreach (string file in fileList.Files)
        {
            tr = new TableRow();
            td = new TableCell();
            td.Width = Unit.Percentage(100);

            td.CssClass = "nohilite";

            td.Attributes.Add("onDblClick", 
                    string.Format("DoBrowse(this, '{0}', 
                    false)", file));
            td.Attributes.Add("onClick", "HighLight(this, '')");

            System.Web.UI.WebControls.Image fileImage = 
                  new System.Web.UI.WebControls.Image();
            fileImage.ImageAlign = ImageAlign.AbsMiddle;
            fileImage.ImageUrl = "Images/file.gif";

            td.Controls.Add(fileImage);
            td.Controls.Add(new 
               LiteralControl("<SPAN class='\"text\"'> " + 
               file + ""));

            tr.Cells.Add(td);
            tb.Rows.Add(tr);
        }
        
        _browsePlaceholder.Controls.Add(tb);
    }
}

Helper Class - FileList

Does all the actual work of getting the ArrayList of directories and files.

protected void ParseHTTPPage ( string directory, string filter)
{
    try
    {
        string[] filterlist = filter.Split(';');
        if (!FileList.IsHTMLContent(directory))
            directory = GetPath(directory);

        string uristring = ExtractUrifromUrl(directory);

        WebClient client = new WebClient();
        byte[] pagedata = client.DownloadData(directory);
        string[] hrefs = ExtractHrefsFromPage(pagedata);
        
        ArrayList dirs = new ArrayList();
        ArrayList files = new ArrayList();
        foreach (string uri in hrefs)
        {
            if (uri.EndsWith("/"))
            {
                //    handle the directory

                if (uri.StartsWith(uristring))
                    dirs.Add(uri.Substring(uristring.Length).Trim('/'));
            }
            else
            {
                string file = Path.GetFileName(uri);
                foreach (string query in filterlist)
                {
                    if (System.Text.RegularExpressions.Regex.IsMatch(file, 
                      "." + query.Replace(".", "\\."), 
                      RegexOptions.IgnoreCase))
                    {
                        files.Add(file);
                        break;
                    }
                }
            }
        }
        
        _directories = new string[dirs.Count];
        dirs.CopyTo(_directories);
        System.Array.Sort(_directories);
        
        _files = new string[files.Count];
        files.CopyTo(_files);
        System.Array.Sort(_files);
        
        _basedirectory = directory;
        if (!_basedirectory.EndsWith("/"))
            _basedirectory += "/";
    }
    catch(Exception except)
    {
        System.Diagnostics.Trace.WriteLine("Exception" + 
                      " parsing URL: " + except.Message);
    }
    return;
}

protected void PasreUNCPage ( string directory, string filter)
{
    try
    {
        if (FileAttributes.Directory != 
          (FileAttributes.Directory & 
          File.GetAttributes(directory)))
            directory = GetPath(directory);
    }
    catch(Exception)
    {
        return;
    }
    
    try
    {
        _directories = 
          RelativePaths( Directory.GetDirectories(directory, "*.*"));
        System.Array.Sort(_directories);
    }
    catch(Exception except)
    {
        System.Diagnostics.Trace.WriteLine("Exception" + 
               " parsing directory: " + except.Message);
    }
    
    try
    {
        _files = new string[0];
        string[] extensions = filter.Split(';');
        foreach (string ext in extensions)
        { 
            string[] foundfiles = 
              RelativePaths( Directory.GetFiles(directory, ext));
            if (foundfiles.Length > 0)
            {
                string[] newlist = new string[_files.Length 
                                            + foundfiles.Length];
                _files.CopyTo(newlist, 0);
                foundfiles.CopyTo(newlist, _files.Length);
                _files = newlist;
                System.Array.Sort(_files);
            }
        }
    }
    catch(Exception except)
    {
        System.Diagnostics.Trace.WriteLine("Exception" + 
                    " parsing files: " + except.Message);
    }

    _basedirectory = directory;
    if (!_basedirectory.EndsWith("\\"))
        _basedirectory += "\\";
    return;
}

Helper Class - PathHelper

Does any of the path handling functions.

Points of Interest

Check out more code samples and components here.

History

Date posted: July 14, 2004.