Our WinForms application needs a filter on the DataGridView control. The google search took me back to July 2006 when Microsoft published Building a Drop-Down Filter List for a DataGridView Column Header Cell.

Building a Drop-Down Filter List for a DataGridView Column Header Cell by Karl Erickson

Fast forward back to 2017. Turns out someone put the code on codeplex under datagridviewfilter and I just downloaded the sources.

1. Add 3 files to project
2. find-replace DataGridViewTextBoxColumn -> DataGridViewAutoFilterTextBoxColumn
3. done