title: Placing a TextBox on top of a header column in a DataGridView
body: <p>I have the following function that responds to the ColumnHeaderMouseDoubleClick event in a DataGridView:</p>
  
  <pre><code>void grid_ColumnHeaderMouseDoubleClick(object sender, DataGridViewCellMouseEventArgs e) {
      TextBox t = new TextBox();
      //make the new textbox the same size as the header to cover it up until text is entered
      t.Width = ((DataGridView)sender).CurrentCell.ContentBounds.Width;
      t.Height = ((DataGridView)sender).CurrentCell.ContentBounds.Height;
      t.Dock = DockStyle.Fill;
      t.Visible = true;
      t.BringToFront();
      t.Text = "TEST";
      Controls.Add(t);
  }
  </code></pre>
  
  <p>All of this code is happening inside of a class that extends Panel and had a DataGridView added to the controls of the panel. When I double click on a header and put a breakpoint on this handler the handler is called, but I don't see the textbox anywhere. Does anybody know what I'm doing wrong?</p>