C#

images.Images.Add(new Bitmap("TreeViewImages.bmp"));  // 0 - 59
...
images.ImageSize = new System.Drawing.Size(16,16);

images.ImageSize = new System.Drawing.Size(960,16);

TreeView Tree = new TreeView();
TreeViewImageHelper helper = new TreeViewImageHelper();
...
Tree.ImageList = helper.CreateImageList();

public class TreeViewImageHelper
{
  private static string assemblyname = null;
  private static Assembly assembly = null;

  public TreeViewImageHelper() { }

  public ImageList CreateImageList()
  {
    ImageList list = new ImageList();

    string[] filenames = {
      "Certificate.bmp",
      "CertificateSelected.bmp",
      "Message.bmp",
      "MessageSelected.bmp",
      null
    };

    for (int i = 0; filenames[i] != null; i++)
    {
      Stream stream = GetEmbeddedFile(filenames[i]);
      if (null != stream)
      {
        list.Images.Add(Bitmap.FromStream(stream));
      }
    }
    return list;
  }

  public Stream GetEmbeddedFile( string filename )
  {    
    if( null == assemblyname )
    { assemblyname = Assembly.GetExecutingAssembly().GetName().Name; }

    if (null == assembly)
    { assembly = System.Reflection.Assembly.Load(assemblyname); }

    Stream bitmapstream = null;
    try
    {
      bitmapstream = assembly.GetManifestResourceStream(
        assemblyname + ".Resources" + "." + filename
      );
    }
    catch
    { return null; }
    
    return bitmapstream;
  }

  public int GetImageIndex(int number)
  {
    // return the appropriate index...
  }
}

Luc Pattyn wrote:

- what is GetTagNumber()?

Luc Pattyn wrote:

- why the detour, why not just have a global imageIndex that increments by 2?

Luc Pattyn wrote:

- the MSDN example sets TreeView.ImageList after the list has been loaded.

} catch(Exception exc) {
    log(exc.ToString());
    return null;
}

if(null == assemblyname) {
    assembly=Assembly.GetExecutingAssembly();
    assemblyname = assembly.GetName().Name;
    log("assemblyname ="+assemblyname);
}

Luc Pattyn wrote:

foreach(string filename in filenames) {...}

Luc Pattyn wrote:

And of course you should use a try-catch: there is input/output involved, it can always
fail (some one/some process could move/delete a file/folder before you could click OK,
a network drive could suddenly get disconnected, etc.)