Example of visual style applied to a button

public partial class Expando : Button
{
public bool Pressed { get; set; }
public Expando()
{
InitializeComponent();
}

protected override void OnPaint(PaintEventArgs pe)
{
VisualStyleRenderer renderer;
if(Pressed)
renderer= new VisualStyleRenderer(VisualStyleElement.ExplorerBar.NormalGroupExpand.Normal);
else
renderer = new VisualStyleRenderer(VisualStyleElement.ExplorerBar.NormalGroupCollapse.Normal);

pe.Graphics.Clear(BackColor);
renderer.DrawBackground(pe.Graphics, this.DisplayRectangle);
}

protected override void OnClick(EventArgs e)
{
Pressed = !Pressed;
base.OnClick(e);
Refresh();
}
}