static string NumberOnlyCodeAppend(KeyInfo keyInfo, out bool isPackageFinished)
        {
            if (keyInfo.IsPressed)
            {
                isPackageFinished = false;
                return("");
            }
            switch (keyInfo.Key)
            {
            case Keys.D1:
            case Keys.NumPad1:
                isPackageFinished = false;
                return("1");

            case Keys.D2:
            case Keys.NumPad2:
                isPackageFinished = false;
                return("2");

            case Keys.D3:
            case Keys.NumPad3:
                isPackageFinished = false;
                return("3");

            case Keys.D4:
            case Keys.NumPad4:
                isPackageFinished = false;
                return("4");

            case Keys.D5:
            case Keys.NumPad5:
                isPackageFinished = false;
                return("5");

            case Keys.D6:
            case Keys.NumPad6:
                isPackageFinished = false;
                return("6");

            case Keys.D7:
            case Keys.NumPad7:
                isPackageFinished = false;
                return("7");

            case Keys.D8:
            case Keys.NumPad8:
                isPackageFinished = false;
                return("8");

            case Keys.D9:
            case Keys.NumPad9:
                isPackageFinished = false;
                return("9");

            case Keys.D0:
            case Keys.NumPad0:
                isPackageFinished = false;
                return("0");

            case Keys.Enter:
                isPackageFinished = true;
                return("");

            default:
                isPackageFinished = false;
                return("");
            }
        }
 internal KeyStateChangedEventArgs(KeyInfo keyInfo)
 {
     KeyInfo = keyInfo;
 }