C#

// will draw every other item with Red background
if (e.Index % 2 != 0)
{
    e = new DrawItemEventArgs(
        e.Graphics,
        e.Font,
        e.Bounds,
        e.Index,
        e.State,
        e.ForeColor, Color.Red);
}
e.DrawBackground();
if (sender is ListBox)
{
    ListBox listBox = (ListBox)sender;
    e.Graphics.DrawString(
        listBox.Items[e.Index].ToString(),
        e.Font,
        new SolidBrush(e.ForeColor),
        e.Bounds);
}

public class Feed
{
    public Feed(string displayText)
    {
        m_DisplayText = displayText;
        isNew = true;
    }
    private string m_DisplayText;
    private bool isNew;
    public string DisplayText
    {
        get { return m_DisplayText; }
    }
    public bool IsNew
    {
        get { return isNew; }
    }
    public void SetRead()
    {
        isNew = false;
    }
    public override string ToString()
    {
        return m_DisplayText;
    }
}

private Color unreadForeColor = SystemColors.Window;
private Color unreadBackColor = SystemColors.ControlText;
[DefaultValue(typeof(Color), "Window")]
public Color UnreadForeColor
{
    get { return unreadForeColor; }
    set { unreadForeColor = value; }
}
[DefaultValue(typeof(Color), "ControlText")]
public Color UnreadBackColor
{
    get { return unreadBackColor; }
    set { unreadBackColor = value; }
}
private void FillList()
{
    lstFeeds.DrawMode = DrawMode.OwnerDrawFixed;
    lstFeeds.SelectedIndexChanged += new EventHandler(lstFeeds_SelectedIndexChanged);
    lstFeeds.DrawItem += new DrawItemEventHandler(lstFeeds_DrawItem);
    Feed[] feeds = new Feed[] {
        new Feed("Feed A"),
        new Feed("Feed B"),
        new Feed("Feed C"),
        new Feed("Feed D")};
    lstFeeds.Items.AddRange(feeds);
}
void lstFeeds_SelectedIndexChanged(object sender, EventArgs e)
{
    if (lstFeeds.SelectedIndices.Count > 0)
    {
        foreach (int selectedIndex in lstFeeds.SelectedIndices)
        {
            Feed selectedFeed = (Feed)lstFeeds.Items[selectedIndex];
            selectedFeed.SetRead();
        }
    }
}
void lstFeeds_DrawItem(object sender, DrawItemEventArgs e)
{
    Feed thisItem = (Feed)lstFeeds.Items[e.Index];
    if (thisItem.IsNew)
    {
        e = new DrawItemEventArgs(
            e.Graphics,
            e.Font,
            e.Bounds,
            e.Index,
            e.State,
            UnreadForeColor,
            UnreadBackColor);
    }
    e.DrawBackground();
    if (sender is ListBox)
    {
        ListBox listBox = (ListBox)sender;
        e.Graphics.DrawString(
            listBox.Items[e.Index].ToString(),
            e.Font,
            new SolidBrush(e.ForeColor),
            e.Bounds);
    }
}

UserControl : ContainerControl<br />
ContainerControl : ScrollableControl, IContainerControl<br />
ScrollableControl : Control, IComponent, IDisposable<br />
Control : Component, IDropTarget, ISynchronizeInvoke, IWin32Window, IBindableComponent, IComponent, IDisposable<br />
Component : MarshalByRefObject, IComponent, IDisposable

using System.ComponentModel;
public class TestControl : Component
{
}

Dave Kreskowiak wrote:

Office 2007 and above now uses an open format XML file to store documents. There's no longer any place to "hide" data.

Dave Kreskowiak wrote:

How big is the payload?

Dave Kreskowiak wrote:

Last I heard, you couldn't fit anything much bigger than an SMS message in it.