Windows Form, DataGrid.

You can use Data Grid’s cell validating event

 

For example in your Data Grid if there are 3 columns

You want second column as required that is user must enter value

 

Following is the code for Cell validating event

 

private void dataGridView1_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)

        {

            if (e.ColumnIndex == 1 && (dataGridView1[e.ColumnIndex, e.RowIndex].EditedFormattedValue == null || dataGridView1[e.ColumnIndex, e.RowIndex].EditedFormattedValue.ToString() == string.Empty))           

                e.Cancel = true;           

           

        }

 

 

Hope this helps