DataGridView cell causing validation on simple arrow keys

Question

Why does DataGridView raise CellValidating event upon simple navigation through arrow keys? How can I prevent it? Here is the key information about DataGridView state when it calls CellValidating :

EditMode = EditOnKeyStrokeOrF2
IsCurrentCellInEditMode = False
e.FormattedValue = [Same as the current value of the cell]

As you can see, user has not triggered any editing operation. He's just moving across the cells by pressing right-arrow key. One would not expect validation to occur at this point, right?

Note: Examining call stack shows that KeyDown event triggers a CommitEdit call, which in turn raises OnCellValidating .

Answer 1

Like it or not, this is the way things are desigend to work. See MSDN on CellValidating :

Occurs when a cell loses input focus, enabling content validation.

And to make it complete MSDN on CellValidated :

Occurs after the cell has finished validating.

The most direct and readable solution is probably to put a line like this at the start of the CellValidating event:

if (!dataGridView1.IsCurrentCellDirty)  return;

One reason for the designed behaviour could be the case where a user input is actually needed to create a valid cell value. Not your case, but still a conceivable requirement.