Catel.MVVM.Converters.TextToUpperCaseConverter.Convert C# (CSharp) Метод

        protected override object Convert(object value, Type targetType, object parameter)
        {
            var stringValue = value as string;
            if (stringValue != null)
            {
#if NETFX_CORE || XAMARIN_FORMS
                return stringValue.ToUpper();
#else
                return stringValue.ToUpper(CurrentCulture ?? CultureInfo.CurrentCulture);
#endif
            }

            return value;
        }
        #endregion

            public void ReturnsNullForNullValue()
            {
                var converter = new TextToUpperCaseConverter();

                Assert.AreEqual(null, converter.Convert(null, typeof(string), null, (CultureInfo)null));
            }