method ToolTip.ShowToolTip (ToolTip as Variant, [Title as Variant], [Alignment as Variant], [X as Variant], [Y as Variant])
Shows the tooltip.

TypeDescription
ToolTip as Variant A String expression that indicates the description of the tooltip, that supports built-in HTML format like described bellow.
Title as Variant If present, A String expression that indicates the title of the tooltip.
Alignment as Variant A long expression that indicates the alignment of the tooltip relative to the position of the cursor. If missing, the tooltip is aligned to the left/top corder. 
X as Variant A single that specifies the current X location of the mouse pointer. The x values is always expressed in screen coordinates. If missing or -1, the current mouse X position is used.  A string expression that indicates the offset to move the tooltip window relative to the cursor position.
Y as Variant A single that specifies the current Y location of the mouse pointer. The y values is always expressed in screen coordinates. If missing or -1, the current mouse Y position is used. A string expression that indicates the offset to move the tooltip window relative to the cursor position.
Use the ShowToolTip method to display programmatically the tooltip. Use the HideToolTip method to hide the tooltip. The ToolTipDelay property specifies the time in ms that passes before the ToolTip appears. Use the ToolTipPopDelay property specifies the period in ms of time the ToolTip remains visible if the mouse pointer is stationary within a control. Use the Font property to change the tooltip's font. Use the Appearance property indicates the visual appearance of the borders of the tooltip. Use the BackColor property indicates the tooltip's background color. Use the ForeColor property indicates the tooltip's foreground color.

The ToolTip parameter supports the following HTML elements:

The Alignment parameter can be one of the followings:

Use  numeric values as strings for X and Y parameters, to move the tooltip window relative to the position of the cursor. For instance, ShowToolTp("text",,,"11","12"), means that the tooltip window is moved 11 pixels on the X axis, and 12 pixels on the Y axis, before showing it in the default position. In this case the X and Y parameters MUST be passed as strings not as LONG values.

The following VB sample displays the tooltip when the cursor hovers the form:

Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
    t.ShowToolTip "This is a bit of text that's shown when the cursor hovers the form"
End Sub

The following VB.NET sample displays the tooltip when the cursor hovers the form:

Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
    t.ShowToolTip("This is a bit of text that's shown when the cursor hovers the form")
End Sub

The following C# sample displays the tooltip when the cursor hovers the form:

private void Form1_MouseMove(object sender, MouseEventArgs e)
{
    t.ShowToolTip("This is a bit of text that's shown when the cursor hovers the form", "", "", "", "" );
}

The following C++ sample displays the tooltip when the cursor hovers the form:

BOOL PreTranslateMessage(MSG* pMsg) 
{
	/* 
		Handles the WM_MOUSEMOVE message during the PreTranslateMessage so it can show the tooltip even if we move the mouse over the inside controls too. 
		As the WM_MOUSEMOVE message is not sent to dialog, if the cursor hovers the inside windows...
	*/
	if ( pMsg->message == WM_MOUSEMOVE )
	{
		if ( m_spToolTip != NULL )
			m_spToolTip->ShowToolTip( COleVariant( "This is a bit of text that's shown when the cursor hovers the form" ), vtMissing, vtMissing, vtMissing );
	}
	return CDialog::PreTranslateMessage(pMsg);
}

The following VFP sample displays the tooltip when the cursor hovers the form:

LPARAMETERS nButton, nShift, nXCoord, nYCoord

with t
    .ShowToolTip("This is a bit of text that's shown when the cursor hovers the form")
endwith