ATMLCommonLibrary.controls.validators.RangeFieldValidator.Validate C# (CSharp) Method

        protected override bool Validate()
        {
            bool valid = true;
            if (IsEnabled && ControlToValidate.Enabled)
            {
                // Is valid if different than initial value,
                // which is not necessarily an empty string
                string controlValue = ControlToValidate.Text.Trim();
                string initialValue;
                if (_initialValue == null) initialValue = "";
                else initialValue = _initialValue.Trim();
                double value;
                _isValid = double.TryParse(controlValue, out value);
                // Display an error if ControlToValidate is invalid
                string errorMessage = "";
                if (_isValid)
                {
                    if ((_lowRange != null && value < _lowRange) || (_highRange != null && value > _lowRange))
                    {
                        errorMessage = _errorMessage;
                        if (_icon != null)
                            ErrorProvider.Icon = _icon;
                        valid = false;
                        if (ControlToValidate is ATMLControl)
                            ((ATMLControl)ControlToValidate).HasErrors = true;
                    }
                }
                ErrorProvider.SetError(_controlToValidate, errorMessage);
            }
            return valid;
        }