BoldSignEasily embed eSignatures in your .NET applications. Free sandbox with native SDK available.
private void gridControl1_CurrentCellValidateString(object sender, GridCurrentCellValidateStringEventArgs e) { //identify the cell somehow - we assume col2 is the hex col GridCurrentCell cc = this.gridControl1.CurrentCell; if(cc.ColIndex == 2) { foreach (char c in e.Text) { char c1 = c.ToString().ToLower()[0]; if("abcdef0123456789".IndexOf(c1) == -1) { e.Cancel = true; break; } } } }