gridview row height

You should simply google around to find tons of examples.
You must use the property Height of data grid view.
This changes all rows height one by one:

foreach (DataGridViewRow row in    Mydgv.Rows)
{
    row.Height =27;
}

To change all in one shot use the trick to change the MinimumHeight property.

Mydgv.RowTemplate.MinimumHeight = 27;

Some more samples here[^].