title: DataGridView Tooltip showing, even when form not focused
body: <p><strong>Given</strong>: I have a DataGridView list-based application that uses that uses an external Tooltip (default dgv tooltipp is disabled) to display the large content of a specific column on mouseover.</p>
  
  <p><strong>The problem</strong>:</p>
  
  <p>It always shows the tooltip on mouseover, even, when the form itself is not in focus. </p>
  
  <p><strong>Scenario</strong>:</p>
  
  <ul>
  <li>I'm running my application + Firefox at the same time in non fullscreen mode. </li>
  <li>Using my application i get the tooltip I want.</li>
  <li>Then i am switching to the half overlaying Firefox.</li>
  <li>While my application is behind Firefox it keeps showing the tooltip on top of Firefox, while the form itself is behind it. </li>
  </ul>
  
  <p>Scenario #2:</p>
  
  <ul>
  <li>My application is showing me a tooltip as it is supposed to.</li>
  <li>I decide to delete that Gridview entry by pressing del-button on my keyboard which opens a yes/no-msgbox.</li>
  <li>the tooltip is displaying on top of the msgbox which makes me unable to use the msgbox buttons with my mouse</li>
  </ul>
  
  <p><strong>The settings</strong>:</p>
  
  <p><a href="https://i.stack.imgur.com/QmcV1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QmcV1.png" alt="enter image description here"></a></p>
  
  <p>Code:</p>
  
  <pre><code>Private Sub gridView_CellMouseEnter(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellMouseEnter
          If e.ColumnIndex = DirectCast(sender, DataGridView).Columns.Count - 1 And Not e.RowIndex = -1 Then
              ToolTip1.SetToolTip(sender, sender.rows(e.RowIndex).cells(e.ColumnIndex).value.ToString)
          End If
  End Sub
  </code></pre>
  
  <p>What do i need to do to fix that annoying bug?</p>