Creating a Row Highlighter for a DataGridView Control

Introduction

Recently, while working on a grid in Winforms, I found myself trying to see if I could highlight the row as I moused over it purely as a cosmetic enhancement to the application.

Using the Code

I used the MouseMove event of the DataGridView as this event is fired when the mouse is over the control and is more suited to altering the controls appearance. Further reading on the event is on MSDN.

int previousRow = 0;

private void dataGridView1_MouseMove(object sender, MouseEventArgs e)
{
  DataGridView.HitTestInfo testInfo = DataGridView1.HitTest(e.X, e.Y);

  //Need to check to make sure that the row index is 0 or greater as the first
  //row is a zero and where there is no rows the row index is a -1
  if(testInfo.RowIndex >= 0 && testInfo.RowIndex != PreviousRow)
  {
    dataGridView1.Rows[previousRow].Selected = false;
    dataGridView1.Rows[testInfo.RowIndex].Selected = true;
    previousRow = testInfo.RowIndex;
  }
}

Points of Interest

If you wish to change the background colour of the selected row, you will need to change SelectionBackColor which can be found by using the following:

dataGridView1.DefaultCellStyle.SelectionBackColor = Color.Yellow;

History

• Original version