Display a tooltip over a button using Windows Forms

Question

How can I display a tooltip over a button using Windows Forms?

Answer 1

Lazy and compact storing text in the Tag property

If you are a bit lazy and do not use the Tag property of the controls for anything else you can use it to store the tooltip text and assign MouseHover event handlers to all such controls in one go like this:

private System.Windows.Forms.ToolTip ToolTip1;
private void PrepareTooltips()
{
    ToolTip1 = new System.Windows.Forms.ToolTip();
    foreach(Control ctrl in this.Controls)
    {
        if (ctrl is Button && ctrl.Tag is string)
        {
            ctrl.MouseHover += new EventHandler(delegate(Object o, EventArgs a)
            {
                var btn = (Control)o;
                ToolTip1.SetToolTip(btn, btn.Tag.ToString());
            });
        }
    }
}

In this case all buttons having a string in the Tag property is assigned a MouseHover event. To keep it compact the MouseHover event is defined inline using a lambda expression. In the event any button hovered will have its Tag text assigned to the Tooltip and shown.