How to set the column header as selected in the datagridview in Winform?

To set the column headers of DataGridView in Winform to a selected state, you can use the following code:

dataGridView1.Columns[columnIndex].HeaderCell.Selected = true;

The columnIndex is the index of the column to be set as selected. You can use this code to set the column header to selected status after loading data or whenever needed.