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Posted 30 May 2004

Themed Windows XP style Explorer Bar

, 6 Oct 2005
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A fully customizable Windows XP style Explorer Bar that supports Windows XP themes and animated expand/collapse with transparency.

Default XP theme

Forever Blue theme

Classic theme

OS X Panther theme

XtremeXP theme

iTunes theme



Windows XP style Explorer Bars/Task Bars/Web Views - call them what you will - are all the rage at the moment. There are many great free Explorer Bar controls available on the net such as Derek Lakin's Collapsible Panel Bar, Darren May's Collapsing Group Control, and Tom Guinther's Full-featured XP Style Collapsible Panel. Most of them don't support Windows XP themes, or if they do, they "fake" it by drawing the gradient/arrows themselves, or by including the necessary images in the assembly.

Frustrated by this lack of proper theme support, I decided to make my own.


  • Windows XP theme support - even on pre XP versions
  • Animated expand/collapse with fade effect
  • Animated show/hide of items with slide effect
  • Automatic layout of all groups and their items
  • Groups can start collapsed or expanded
  • Group re-ordering (including at design time)
  • Focus and keyboard navigation similar to Windows XP's Explorer Bar
  • User defined settings - gradients, colors, borders and more
  • Supports .NET Framework versions 1.0 and 1.1
  • Supports Binary and XML Serialization


So, how can we make use of themes?

My first attempt was to take screenshots of the real Explorer Bar in action so I could get the images and colors that I would need. This worked well as long as I only used the Luna themes that come with XP. I was forced to go back to the drawing board.

After stumbling across Don Kackman's article on Adding XP Themes to Custom .NET Controls, attempt #2 was to make use of UxTheme.dll. That was until I got to the part where using UxTheme worked as long as you only used the default Blue Luna theme. However, Don came up with a potential solution - get the necessary information from ShellStyle.dll.


Now that I knew where to look, the question was "what am I looking for?" TGTSoft (the makers of StyleXP) have a great free program called ResBuilder that allows you to open and modify Windows resource files. Armed with this program, I was able to have a poke around inside ShellStyle.dll.

ShellStyle.dll in ResBuilder

Figure 1: ShellStyle.dll in ResBuilder

The sections I needed were the Bitmap (obviously) and the UIFILE - more on these later.

Before loading the ShellStyle.dll, we need to check whether themes are available:

// check if we are using themes. if so, load up the
// appropriate shellstyle.dll
if (UxTheme.AppThemed && LoadShellStyleDll())

If they are available, then go ahead and load the ShellStyle.dll:

/// Loads the ShellStyle.dll into memory as determined by the current
/// system theme
private static bool LoadShellStyleDll()
   // work out the path to the shellstyle.dll according
   // to the current theme
   string themeName = UxTheme.ThemeName.Substring(0, 
   string styleName = themeName + "\\Shell\\" + UxTheme.ColorName;
   string stylePath = styleName + "\\shellstyle.dll";

   // if for some reason it doesn't exist, use the default 
   // shellstyle.dll in the windows\system32 directory
   if (!File.Exists(stylePath))
      stylePath = Environment.GetFolderPath(Environment.SpecialFolder.System) + 

   // attempt to load the shellstyle dll
   hModule = LoadLibrary(stylePath);

   // return whether we succeeded
   return (hModule != IntPtr.Zero);


So, what is a UIFILE? The UIFILE is basically a style sheet that tells the Explorer Bar how it should render itself. Below is a small section that shows settings for a special group's titlebar for the Blue Luna theme:

button [id=atom(header)]
   background: rcbmp(110,6,#FF00FF,0,0,1,0);
   borderthickness: rect(2,2,2,0);
   foreground: white;
   fontweight: rcint(10);
   padding: rect(10,0,0,0);
   animation: rectanglev | s | fast;

(For more information on UIFILEs, has a tutorial on how to read a UIFILE).

You'll notice that there are two UIFILEs - the first one is for the Explorer Bar, and the second is for the Control Panel. Now that we know which one we want, it is time to read its contents:

/// Extracts the UIFILE from the currently loaded ShellStyle.dll
public static string GetResourceUIFile()
   // locate the "UIFILE" resource
   IntPtr hResource = FindResource(hModule, "#1", "UIFILE");

   // get its size
   int resourceSize = SizeofResource(hModule, hResource);

   // load the resource
   IntPtr resourceData = LoadResource(hModule, hResource);

   // copy the resource data into a byte array so we
   // still have a copy once the resource is freed
   byte[] uiBytes = new byte[resourceSize];
   GCHandle gcHandle = GCHandle.Alloc(uiBytes, GCHandleType.Pinned);
   IntPtr firstCopyElement = Marshal.UnsafeAddrOfPinnedArrayElement(uiBytes, 0);
   CopyMemory(firstCopyElement, resourceData, resourceSize);

   // free the resource

   // convert the char array to an ansi string
   string s = Marshal.PtrToStringAnsi(firstCopyElement, resourceSize);

   return s;

Extracting Bitmaps

All bitmaps in the UIFILE have the following format:

rcbmp(id, stretching, transparency, width, height, size, mirror)

To load a bitmap, we just pass the bitmap ID to the GetResourceBMP method:

/// Returns a Bitmap from the currently loaded ShellStyle.dll
public static Bitmap GetResourceBMP(string resourceName)
   // find the resource
   IntPtr hBitmap = LoadBitmap(hModule, Int32.Parse(resourceName));

   // load the bitmap
   Bitmap bitmap = Bitmap.FromHbitmap(hBitmap);

   return bitmap;

The method above works for ordinary bitmaps, but we run into a major problem if the image is a 32bpp PNG - the alpha channel is lost, leaving black areas where the transparency should be.

Alpha channel comparison

Figure 2: Alpha channel comparison

The following solution to this problem was posted on Derek Lakin's blog:

/// Returns a Png Bitmap from the currently loaded ShellStyle.dll
public static Bitmap GetResourcePNG(string resourceName)
   // the resource size includes some header information 
   // (for PNG's in shellstyle.dll this appears to be the 
   // standard 40 bytes of BITMAPHEADERINFO).
   const int FILE_HEADER_BYTES = 40;

   // load the bitmap resource normally to get dimensions etc.
   Bitmap tmpNoAlpha = Bitmap.FromResource(hModule, "#" + resourceName);
   IntPtr hResource = FindResource(hModule, "#" + resourceName, 
                                   (IntPtr) 2 /*RT_BITMAP*/);
   int resourceSize = SizeofResource(hModule, hResource);

   // initialise 32bit alpha bitmap (target)
   Bitmap bitmap = new Bitmap(tmpNoAlpha.Width, 

   // load the resource via kernel32.dll (preserves alpha)
   IntPtr hLoadedResource = LoadResource(hModule, hResource);

   // copy bitmap data into byte array directly
   byte[] bitmapBytes = new byte[resourceSize];
   GCHandle gcHandle = GCHandle.Alloc(bitmapBytes, GCHandleType.Pinned);
   IntPtr firstCopyElement = 
        Marshal.UnsafeAddrOfPinnedArrayElement(bitmapBytes, 0);
   // nb. we only copy the actual PNG data (no header)
   CopyMemory(firstCopyElement, hLoadedResource, resourceSize);

   // copy the byte array contents back
   // to a handle to the alpha bitmap (use lockbits)
   Rectangle copyArea = new Rectangle(0, 0, bitmap.Width, bitmap.Height);
   BitmapData alphaBits = bitmap.LockBits(copyArea, 

   // copymemory to bitmap data (Scan0)
   firstCopyElement = Marshal.UnsafeAddrOfPinnedArrayElement(bitmapBytes, 
   CopyMemory(alphaBits.Scan0, firstCopyElement, 
                  resourceSize - FILE_HEADER_BYTES);

   // complete operation

   // flip bits (not sure why this is needed at the moment..)

   return bitmap;

So, how do we know which one to use for each image? Generally speaking, normal bitmaps will use a hexadecimal transparency value, while PNGs will use an integer value.

// if the transparency value starts with a #, then the image is
// a bitmap, otherwise it is a 32bit png
if (transparent.StartsWith("#"))
   // get the bitmap
   image = Util.GetResourceBMP(id);

   // get the png
   image = Util.GetResourcePNG(id);


The XPExplorerBar consists of three main components:

  1. The TaskPane
  2. Expandos, and
  3. TaskItems

I won't go into great detail about how each of these were implemented as that is what the source code is for, but I will give an insight into some of the more interesting features such as animation.

Using XPExplorerBar

Before using the XPExplorerBar, you need to add a reference to XPExplorerBar.dll in the References section of your project.

To add the XPExplorerBar.dll to the toolbox, you can either:

  1. Select Tools -> Add/Remove Toolbox Items from the menu, or
  2. Right click on the toolbox, select Add/Remove Items.

and browse for XPExplorerBar.dll and then press OK. You can then drag the controls onto your Form.

Note: If you recompile the source code you will need to re-sign XPExplorerBar.dll, as otherwise Visual Studio will throw an exception when you attempt to add it to the toolbox.

  1. Open up the VS.NET command prompt and change the directory to point to the XPExplorerBar\bin\Release directory.
  2. Then type "sn -R XPExplorerBar.dll ..\..\XPExplorerBar.snk" (without the quotes of course).

You should then be able to add it to the toolbox.


The TaskPane acts as a container for all the Expandos that the XPExplorerBar will contain.

  • Expandos

    An ExpandoCollection representing the collection of Expandos contained within the TaskPane.

  • CustomSettings

    The custom settings used to draw the TaskPane.

    Note: Changing one of these settings will override the same system setting defined in a shellstyle.dll.

Adding Expandos to a TaskPane

There are two ways to add Expandos to a TaskPane:

  • Via the Expandos property in the property editor window, or
  • Dragging Expandos from the toolbox onto a TaskPane

Adding Expandos with the property editor

Figure 3: Adding Expandos with the property editor

Reordering Expandos

During design time, you can use the up and down arrow buttons in the Expando Collection Editor to reorder the Expandos.

Use arrow buttons to reorder Expandos at design time

Figure 4: Use arrow buttons to reorder Expandos at design time

At all other times, the TaskPane's Expandos property provides the following methods to reorder Expandos:

  • Move(Expando value, int index)

    Moves the specified Expando to the specified indexed location in the ExpandoCollection.

  • MoveToTop(Expando value)

    Moves the specified Expando to the top of the ExpandoCollection.

  • MoveToBottom(Expando value)

    Moves the specified Expando to the bottom of the ExpandoCollection.

// Move an Expando to the top of the TaskPane

Using Themes Other Than The Current Theme

The XPExplorerBar also allows you to use themes that are different to the current theme.

  • UseClassicTheme()

    Forces the TaskPane and all its Expandos to use a theme equivalent to Windows XP's Classic Theme (this is the default theme on Windows 2000 or earlier).

  • UseCustomTheme(string stylePath)

    Forces the TaskPane and all its Expandos to use the specified theme.

  • UseDefaultTheme()

    Forces the TaskPane and all its Expandos to use the current system theme.

UseClassicTheme() and UseDefaultTheme() will appear to do the same thing on Windows versions prior to XP, or on XP machines with themes disabled. Note that UseCustomTheme() will work on Windows 2000 or earlier.

TaskPane taskpane = new TaskPane();

// foreverblue.dll lives in the same directory as
// the executable. if it were somewhere else, we
// would need to use "path/to/foreverblue.dll"

XPExplorerBar demo with Windows XP theme Forever Blue on Windows 2000

Figure 5: XPExplorerBar demo with Windows XP theme Forever Blue on Windows 2000

Custom themes can be found at ThemeXP.

Collapsing/Expanding Multiple Expandos

The XPExplorerBar now allows you to expand or collapse multiple Expandos at the same time.

  • CollapseAll()

    Collapses all the Expandos contained in the TaskPane.

  • ExpandAll()

    Expands all the Expandos contained in the TaskPane.

  • CollapseAllButOne(Expando expando)

    Collapses all the Expandos contained in the TaskPane, except for the specified Expando which is expanded.


Expandos are containers for TaskItems and other Controls, and can be collapsed/expanded as necessary. Note that Expandos will only animate if they are added to a TaskPane.

I'm sure that right about now, you're wondering where I got the name Expando from. If you look at the UIFILE, you will get an idea (it's the name Microsoft has given the collapsible group).

  • Animate

    Determines whether the Expando will perform collapse/expand or show/hide animations.

  • AutoLayout

    Determines whether the Expando will automagically layout its items.

  • Collapsed

    Determines whether the Expando is collapsed or expanded.

  • CustomSettings

    The custom settings used to draw the Expando's body.

    Note: Changing one of these settings will override the same system setting defined in a shellstyle.dll.

  • CustomHeaderSettings

    The custom settings used to draw the Expando's title bar.

    Note: Changing one of these settings will override the same system setting defined in a shellstyle.dll.

  • ExpandedHeight

    Sets the height of the Expando in its expanded state. This is ignored if the AutoLayout property is used.

  • Items

    An ItemCollection representing the collection of Controls contained within the Expando.

  • ShowFocusCues

    Gets or sets a value indicating whether the Expando should display focus rectangles when it has focus.

  • SpecialGroup

    Determines whether the Expando will be rendered as a Special Group.

  • TitleImage

    Specifies the Image that is displayed on the left side of the Expando's titlebar.

Adding Controls to an Expando

There are two ways to add Controls to an Expando:

  • Via the Items property in the property editor window, or
  • Dragging Controls from the toolbox onto an Expando.

Adding Controls with the property editor

Adding Controls with the property editor

Figure 6a (top) and 6b (bottom): Adding Controls with the property editor.

Version 3.0 now allows other Controls besides TaskItems to be added via the Items property in the designer. Clicking the Add button will add a TaskItem to the Expando, while clicking the arrow next to the Add button will provide a list of the more useful Controls to add to the Expando.

Reordering Controls

During design time, you can use the up and down arrow buttons in the Control Collection Editor to reorder the Controls.

Use arrow buttons to reorder Controls at design time

Figure 7: Use arrow buttons to reorder Controls at design time

At all other times, the Expando's Items property provides the following methods to reorder Controls:

  • Move(Control value, int index)

    Moves the specified Control to the specified indexed location in the ItemCollection.

  • MoveToTop(Control value)

    Moves the specified Control to the top of the ItemCollection.

  • MoveToBottom(Control value)

    Moves the specified Control to the bottom of the ItemCollection.

// Move a TaskItem to the top of the Expando

As of v3.3 Expandos can now be dragged around a TaskPane. For this to happen the TaskPane's AllowExpandoDragging property should be set to true.

Dragging Expandos

Figure 8: Dragging Expandos around a TaskPane

Hide/Show Controls

In order to hide or show items, the HideControl and ShowControl methods have been provided. You shouldn't use control.Visible = false to hide items, as the Expando will need to make the control visible again in order to perform an expand animation without any visual artifacts (such as a black background for some themed controls), most likely causing the control to stay visible when it should be hidden, as well as cause a few layout headaches.

  • HideControl(Control control)

    Hides the specified Control.

  • HideControl(Control[] controls)

    Hides the specified array of Controls.

  • ShowControl(Control control)

    Shows the specified Control.

  • ShowControl(Control[] controls)

    Shows the specified array of Controls.

Note: In order for the Expando to perform an animation, the Expando's AutoLayout and Animate properties must all be true.

Note: As of version 3.3 you can batch HideControl/ ShowControl commands using the BeginUpdate()/ EndUpdate() methods:

// stop the following slide animation 
// commands from being performed

expando.HideControl(new Control[] {taskItem1, taskItem2});

// now perform the animations

Note: At the moment the BeginUpdate()/EndUpdate() methods are only useful for this purpose.

Docking and Scrolling

A docked scrollable Panel

Figure 9: A docked scrollable Panel

As of version 3.0, Expandos no longer support scrolling. The way that scrolling was implemented in version 2.x caused a few rendering problems that I have yet to resolve. Hopefully by removing scroll support in this version I will have more time to fix the problems, and add scrolling support back in a future version (as opposed to delaying releases). Apologies for any inconvenience this may cause.

To add scrolling, simply add a scrollable Panel and set its DockStyle property to Fill.

To stop child controls from covering the title bar and borders when docked, I overrode the Expando's DisplayRectangle property.

/// Overrides DisplayRectangle so that docked controls
/// don't cover the titlebar or borders
public override Rectangle DisplayRectangle
      return new Rectangle(this.Border.Left, 
                           this.HeaderHeight + this.Border.Top,
                           this.Width - this.Border.Left - this.Border.Right,
                           this.ExpandedHeight - this.HeaderHeight - 
                           this.Border.Top - this.Border.Bottom);


Animated collapse in action

Figure 10: Animated collapse in action

To enable collapse/expand animation, the Expando's Animate property must be set to true:

/// Gets or sets whether the Expando is allowed to animate.
public bool Animate
      return this.animate;

      this.animate = value;

When the Expando's Collapsed property changes, it checks whether it can animate.

/// Gets or sets whether the Expando is collapsed.
public bool Collapsed

      if (this.collapsed != value)
         // if we're supposed to collapse, check if we can
         if (value && !this.CanCollapse)
            // looks like we can't so time to bail

         this.collapsed = value;

         // only animate if we're allowed to, we're not in 
         // design mode and we're not initialising
         if (this.Animate && !this.DesignMode && !this.Initialising)

If the Expando is able to animate, it creates a new AnimationHelper that tells the Expando to get ready and starts the animation timer.


            this.animationHelper = new AnimationHelper(this, 

            this.OnStateChanged(new ExpandoEventArgs(this));



/// Starts the animation for the specified expando
protected void StartAnimation()
   // don't bother going any further if we are already animating
   if (this.Animating)

   this.animationStepNum = 0;

   // tell the expando to get ready to animate
   if (this.AnimationType == FadeAnimation)

   // start the animation timer

Once the Expando receives the StartAnimation message, it takes a "snap-shot" of its "client area" (i.e., its dockable area). All the Expando's child controls are set invisible as otherwise they would appear to slide off the bottom of the Expando (also controls that have their FlatStyle property set to System don't like having their opacity changed).

/// Gets the Expando ready to start its collapse/expand animation
protected void StartAnimation()
   this.animating = true;

   // stop the layout engine

   // get an image of the client area that we can
   // use for alpha-blending in our animation
   this.animationImage = this.GetAnimationImage();

   // set each control invisible (otherwise they
   // appear to slide off the bottom of the group)
   foreach (Control control in this.Controls)
      control.Visible = false;

   // restart the layout engine

/// Returns an image of the group's display area to be used
/// in the animation
internal Image GetAnimationImage()
   // create a new image to draw into
   Image image = new Bitmap(this.Width, this.Height);
   // get a graphics object we can draw into
   Graphics g = Graphics.FromImage(image);
   IntPtr hDC = g.GetHdc();

   // some flags to tell the control how to draw itself
   IntPtr flags = (IntPtr) (WmPrintFlags.PRF_CLIENT | 
                            WmPrintFlags.PRF_CHILDREN | 

   // tell the control to draw itself
                             hDC, flags);

   // clean up resources

   // return the completed animation image
   return image;

/// The SendMessage function sends the specified message to a 
/// window or windows. It calls the window procedure for the 
/// specified window and does not return until the window 
/// procedure has processed the message
internal static extern int SendMessage(IntPtr hwnd, 
                                       int msg, 
                                       IntPtr wParam, 
                                       IntPtr lParam);

The animationImage is faded and moved up/down as necessary during the animation.

/// Paints the "Display Rectangle". This is the dockable
/// area of the control (ie non-titlebar/border area). 
protected void PaintDisplayRect(Graphics g)
   // are we animating
   if (this.animating && this.animationImage != null)
      // calculate the transparency value for the animation image
      float alpha = (((float) (this.Height - this.HeaderHeight)) / 
                     ((float) (this.ExpandedHeight - this.HeaderHeight)));

      float[][] ptsArray = {new float[] {1, 0, 0, 0, 0},
                            new float[] {0, 1, 0, 0, 0},
                            new float[] {0, 0, 1, 0, 0},
                            new float[] {0, 0, 0, alpha, 0}, 
                            new float[] {0, 0, 0, 0, 1}}; 

      ColorMatrix colorMatrix = new ColorMatrix(ptsArray);
      ImageAttributes imageAttributes = new ImageAttributes();

      // work out how far up the animation image we need to start
      int y = this.animationImage.Height - this.PseudoClientHeight
               - this.Border.Bottom;

      // draw the image
                  new Rectangle(0, this.HeaderHeight, this.Width, 
                                this.Height - this.HeaderHeight),
                  this.animationImage.Height - y,


A TaskItem

Figure 11: A TaskItem

TaskItems are similar to Labels. Each TaskItem can contain an Image that is restricted to 16x16 pixels. Larger or smaller images can be used, but they will be enlarged/decreased to 16x16 as necessary.

  • CustomSettings

    The custom settings used to draw the TaskItem.

    Note: Changing one of these settings will override the same system setting defined in a shellstyle.dll.

  • Image

    The image that is displayed on a TaskItem.

  • ShowFocusCues

    Gets or sets a value indicating whether the TaskItem should display focus rectangles when it has focus.

Points of Interest


As of v3.2, Binary Serialization support has been reworked and XML Serialization support has been added.

Note: v3.2.1 adds a Version property to the serialization process to ensure backward compatibility with future versions. Anyone using serialization is encouraged to upgrade to v3.2.1

In order to fix the problems that v3.1 had with serialization, I needed to find a new way to perform serialization. After much Googling, I came across the concept of surrogates. A surrogate is a class that will be serialized in place of another class (usually because the other class is either not serializable or contains classes that are not serializable or cause serialization problems).

  • TaskPane.TaskPaneSurrogate

    A class that is serialized instead of a TaskPane.

  • Expando.ExpandoSurrogate

    A class that is serialized instead of an Expando.

  • TaskItem.TaskItemSurrogate

    A class that is serialized instead of a TaskItem.

All the above Surrogates have the following methods for importing/exporting data to/from a Surrogate:

  • Load(object value)

    Populates the Surrogate with data that is to be serialized from the specified object.

  • Save()

    Returns an object that contains the deserialized Surrogate data.

The example below shows how a TaskPane can be serialized and deserialized by a TaskPane.TaskPaneSurrogate with Binary and XML serialization:


// serialize a TaskPane to a file
IFormatter formatter = new BinaryFormatter();
stream = new FileStream("TaskPane.bin", FileMode.Create, FileAccess.Write, 

TaskPane.TaskPaneSurrogate taskPaneSurrogate = 
                                        new TaskPane.TaskPaneSurrogate(); 

formatter.Serialize(stream, taskPaneSurrogate);

// deserialize a TaskPane from a file
IFormatter formatter = new BinaryFormatter();
stream = new FileStream("TaskPane.bin", FileMode.Open, FileAccess.Read, 

TaskPane.TaskPaneSurrogate taskPaneSurrogate = 
              (TaskPane.TaskPaneSurrogate) formatter.Deserialize(stream);

TaskPane taskpane = taskPaneSurrogate.Save();


// serialize a TaskPane to a file
XmlSerializer xml = new XmlSerializer(typeof(TaskPane.TaskPaneSurrogate));
StreamWriter writer = new StreamWriter("TaskPane.xml");

TaskPane.TaskPaneSurrogate taskPaneSurrogate = 
                                        new TaskPane.TaskPaneSurrogate(); 
xml.Serialize(writer, taskPaneSurrogate);

// deserialize a TaskPane from a file
XmlSerializer xml = new XmlSerializer(typeof(TaskPane.TaskPaneSurrogate));
TextReader reader = new StreamReader("TaskPane.xml");

TaskPane.TaskPaneSurrogate taskPaneSurrogate = 
                     (TaskPane.TaskPaneSurrogate) xml.Deserialize(reader);

TaskPane taskpane = taskPaneSurrogate.Save();

Note: Controls in the Expando.ItemCollection that are not TaskItems are ignored during the serialization process as (unfortunately) they do not support serialization.

Visual Styles and WM_PRINT

Update: I sent a bug report to Microsoft about visual styles and WM_PRINT messages (which can be found here[^]) and their response was basically that it would be too hard to fix, so it looks like we're stuck with this workaround until Avalon is released.

Some XP themed controls (TextBox, ListView, TreeView, ListBox, CheckedListBox, DateTimePicker, GroupBox) don't draw a themed border when sent a WM_PRINT message, if Visual Styles are enabled.

TextBox border after WM_PRINT message

Figure 12: TextBox border after WM_PRINT message

In order to solve this problem, I immediately ran into another problem - How to find out if Visual Styles are applied (i.e., a manifest or Application.EnableVisualStyles() is being used). After some Googling, I found this solution which checks if themes are enabled and which version of the Common Controls is being used:

/// Checks whether Visual Styles are enabled
protected bool VisualStylesEnabled
      OperatingSystem os = System.Environment.OSVersion;

      // check if the OS is XP or higher
      if (os.Platform == PlatformID.Win32NT && 
         ((os.Version.Major == 5 && os.Version.Minor >= 1) || 
           os.Version.Major > 5))
         // are themes enabled
         if (UxTheme.IsThemeActive() && UxTheme.IsAppThemed())
            DLLVERSIONINFO version = new DLLVERSIONINFO();
            version.cbSize = Marshal.SizeOf(typeof(DLLVERSIONINFO));

            // are we using Common Controls v6
            if (DllGetVersion(ref version) == 0)
               return (version.dwMajorVersion > 5);

      return false;

/// Receives dynamic-link library (DLL)-specific version information. 
/// It is used with the DllGetVersion function
public struct DLLVERSIONINFO
   public int cbSize;
   public int dwMajorVersion;
   public int dwMinorVersion;
   public int dwBuildNumber;
   public int dwPlatformID;

/// Implemented by many of the Microsoft Windows Shell dynamic-link libraries 
/// (DLLs) to allow applications to obtain DLL-specific version information
public static extern int DllGetVersion(ref DLLVERSIONINFO pdvi);

I then subclassed the offending controls and listened for WM_PRINT messages, and drew themed borders over the top of the unthemed borders, if Visual Styles are enabled.

/// Processes Windows messages
protected override void WndProc(ref Message m)
   base.WndProc(ref m);

   // don't bother if visual styles aren't applied
   if (!this.visualStylesEnabled)

   // WM_PRINT message?
   if (m.Msg == (int) WindowMessageFlags.WM_PRINT)
      // are we supposed to draw the nonclient area?
      // (ie borders)
      if ((m.LParam.ToInt32() & (int) WmPrintFlags.PRF_NONCLIENT) == 
          (int) WmPrintFlags.PRF_NONCLIENT)
         // open theme data
         IntPtr hTheme = UxTheme.OpenThemeData(this.Handle, 

         if (hTheme != IntPtr.Zero)
            // get the part and state needed
            int partId = (int) UxTheme.Parts.Edit.EditText;
            int stateId = (int) UxTheme.PartStates.EditText.Normal;

            // rectangle to draw into
            RECT rect = new RECT();
            rect.right = this.Width;
            rect.bottom = this.Height;

            // clipping rectangle
            RECT clipRect = new RECT();

            // draw the left border
            clipRect.left = rect.left;
            clipRect.right = rect.left + 2;
            clipRect.bottom = rect.bottom;
            UxTheme.DrawThemeBackground(hTheme, m.WParam, partId, stateId, 
                                        ref rect, ref clipRect);

            // do the same for other borders


The subclassed controls (XPTextBox, XPListView, XPTreeView, XPListBox, XPCheckedListBox, XPDateTimePicker) are included in the download.

Known Problems

  • XPExplorerBar may not correctly render non-official XP themes.


  • 30 September 2005 - Version 3.3
    • Added RightToLeft support for Expandos and TaskItems.
    • Added ability to batch HideControl/ShowControl commands for Expandos (see Hide/Show Controls for more details).
    • Added ability for Expandos to be dragged around a TaskPane.
    • Fixed TaskItem's text is sometimes clipped.
    • Other bug fixes.
  • 24 February 2005 - Version
    • Fixed Expando Hide/ShowControl methods trying to animate while Expando is collapsed.
    • Changed UseDefaultTabHandling property so that the default focus and keyboard navigation is enabled by default. To use tab handling similar to Windows XP's Explorer Bar UseDefaultTabHandling must be explicitly set to false.
  • 17 February 2005 - Version
    • Removed excess Serializable attributes from classes which shouldn't be serialized.
    • Added UseDefaultTabHandling property to Expandos so the user can choose the default focus and keyboard navigation or use focus and keyboard navigation similar to Windows XP's Explorer Bar.
  • 22 January 2005 - Version 3.2.1
    • Added Version property for serialization to ensure backward compatibility with future versions.
    • Other bug fixes.
  • 19 January 2005 - Version 3.2
    • Changed the way Binary Serialization works and added XML serialization support.
    • Fixed can't extract images from shellstyle.dlls on Windows 9x bug.
    • Fixed "Resource transformation for file 'Myfile.resx' failed" bug.
    • Improved theme support.
    • Other bug fixes.
  • 2 November 2004 - Version 3.1
    • Added Binary Serialization support for TaskPanes, Expandos, TaskItems, TaskPane.ExpandoCollections and Expando.ItemCollections.
    • Fixed can't add TaskItems or other controls to Expandos programmatically bug which was accidentally reintroduced in v3.0.
    • Other bug fixes.
  • 25 October 2004 - Version 3.0
    • Added custom settings for TaskPanes, Expandos and TaskItems.
    • Removed native scrolling support for Expandos due to rendering issues.
    • Fixed Expandos start at point (0, 0) when added to a TaskPane programmatically bug.
    • Fixed Expandos start with incorrect height if Collapsed and have a TitleImage bug.
    • Other bug fixes
  • 11 October 2004 - Version 2.1
    • Changed Expandos so that collapse/expand arrows and titlebar highlights are not displayed when the CanCollapse property is false.
  • 30 September 2004 - Version 2.0
    • Added native scrolling support for Expandos.
    • Added focus and keyboard navigation similar to Windows XP's Explorer Bar.
    • Fixed bug: can't add Expandos, TaskItems or other controls programmatically.
  • 3 September 2004 - Version 1.4
    • Added Control re-ordering on Expandos.
  • 26 August 2004 - Version 1.3
    • Added Expando re-ordering.
  • 21 August 2004 - Version 1.21
    • Expandos titlebar now rendered in grayscale when disabled.
    • TaskItems render their text the same as a Label when disabled.
    • Improved theme support.
  • 5 August 2004 - Version 1.2
    • Changed name from XPTaskBar to XPExplorerBar.
    • Added show/hide animation.
    • Improved theme support.
  • 3 June 2004 - Version 1.1
    • Added collapse/expand multiple Expandos.
    • Added custom XP theme support.
  • 31 May 2004 - Initial release.


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Mathew Hall
Web Developer
Australia Australia
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Comments and Discussions

GeneralA Question Pin
Brit the Brut20-Mar-07 18:56
memberBrit the Brut20-Mar-07 18:56 
QuestionError on visual studio 2005 Pin
r_nassabeh8-Mar-07 19:31
memberr_nassabeh8-Mar-07 19:31 
AnswerRe: Error on visual studio 2005 Pin
girlinaswing9-Mar-07 0:51
membergirlinaswing9-Mar-07 0:51 
AnswerRe: Error on visual studio 2005 Pin
chiao.vincent17-Mar-07 1:54
memberchiao.vincent17-Mar-07 1:54 
AnswerRe: Error on visual studio 2005 Pin
iJimmyLiu4-Jul-07 20:54
memberiJimmyLiu4-Jul-07 20:54 
QuestionCompatibility with Vista Pin
Satish Thorat22-Feb-07 23:39
memberSatish Thorat22-Feb-07 23:39 
AnswerRe: Compatibility with Vista Pin
FredericSivignonPro23-Feb-07 3:40
memberFredericSivignonPro23-Feb-07 3:40 
GeneralExpando visible problem Pin
amoba22-Feb-07 1:40
memberamoba22-Feb-07 1:40 
QuestionVb.Net 2005? Pin
manschula212-Feb-07 10:39
membermanschula212-Feb-07 10:39 
AnswerRe: Vb.Net 2005? Pin
K32115-Feb-07 10:59
memberK32115-Feb-07 10:59 
GeneralI can't ejecute the app big error[modified] Pin
asuperman152-Feb-07 15:44
memberasuperman152-Feb-07 15:44 
GeneralVista Problems Pin
Chris_McGrath28-Jan-07 17:40
memberChris_McGrath28-Jan-07 17:40 
GeneralRe: Vista Problems Pin
Alon Hirsch19-Feb-07 2:18
memberAlon Hirsch19-Feb-07 2:18 
AnswerUse custom Theme Pin
K32114-Mar-07 10:35
memberK32114-Mar-07 10:35 
JokeRe: Vista Problems Pin
LordPadriac21-Feb-07 3:23
memberLordPadriac21-Feb-07 3:23 
GeneralRe: Vista Problems Pin
Chris_McGrath8-May-07 19:36
memberChris_McGrath8-May-07 19:36 
GeneralRe: Vista Problems Pin
jexia8-Aug-07 18:11
memberjexia8-Aug-07 18:11 
GeneralThanks Pin
Michael_Schmitt29-Dec-06 16:36
memberMichael_Schmitt29-Dec-06 16:36 
GeneralBug Pin
Member 361802527-Dec-06 20:55
memberMember 361802527-Dec-06 20:55 
JokeRe: Bug Pin
abooysen23-Feb-07 8:13
memberabooysen23-Feb-07 8:13 
GeneralRe: Bug Pin
sendi_t3419-Mar-07 10:06
membersendi_t3419-Mar-07 10:06 
AnswerRe: Bug Pin
abooysen19-Mar-07 19:17
memberabooysen19-Mar-07 19:17 
GeneralProblem with .Net FrameWork 2.0 Pin
fifopro20-Dec-06 15:17
memberfifopro20-Dec-06 15:17 
GeneralRe: Problem with .Net FrameWork 2.0 Pin
Member 361802527-Dec-06 20:56
memberMember 361802527-Dec-06 20:56 
Generalexpando's title height Pin
Marc Soleda17-Dec-06 9:01
memberMarc Soleda17-Dec-06 9:01 

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