Treefrog.Windows.Controllers.ValidationController.ValidateNumericUpDownFunc C# (CSharp) Method

        public static Func<string> ValidateNumericUpDownFunc(string fieldName, NumericUpDown control)
        {
            return () => {
                if (control.Value < control.Minimum || control.Value > control.Maximum)
                    return fieldName + " must be in range [" + control.Minimum + ", " + control.Maximum + "].";
                else
                    return null;
            };
        }