I have an automatically binded DataGridView that obtains data and update data directly from a Strongly Typed Dataset and its TableAdapter. the DataGridView allows data editing but I'm having issues dealing with bad formatted data input. For example, one of the columns is a date, formatted in the database as datetime, 11/05/2010. You can edit the date and the DataGridView opens a TextBox in wich you can enter letters, simbols and other unauthorised characters. When you finish editing the cell if has such bad data it throws a System.FormatException How can I prevent some data to be entered? Is there a way to "filter" that data before it is sent back to the DataGridView?