[.net] Display a tooltip over a button using Windows Forms

3 Answers

Using the form designer:

  • Drag the ToolTip control from the Toolbox, onto the form.
  • Select the properties of the control you want the tool tip to appear on.
  • Find the property 'ToolTip on toolTip1' (the name may not be toolTip1 if you changed it's default name).
  • Set the text of the property to the tool tip text you would like to display.

You can set also the tool tip programatically using the following call:

this.toolTip1.SetToolTip(this.targetControl, "My Tool Tip");

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

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.

Sure, just handle the mousehover event and tell it to display a tool tip. t is a tooltip defined either in the globals or in the constructor using:

ToolTip t = new ToolTip();

then the event handler:

private void control_MouseHover(object sender, EventArgs e)
  t.Show("Text", (Control)sender);

For default tooltip this can be used -

System.Windows.Forms.ToolTip ToolTip1 = new System.Windows.Forms.ToolTip();
ToolTip1.SetToolTip(this.textBox1, "Hello world");

A customized tooltip can also be used in case if formatting is required for tooltip message. This can be created by custom formatting the form and use it as tooltip dialog on mouse hover event of the control. Please check following link for more details -