System.Text.Normalization.IsNormalized C# (CSharp) Method

        private bool IsNormalized(String strInput)
        {
            if (strInput == null)
                throw new ArgumentNullException(
                    Environment.GetResourceString("ArgumentNull_String"), "strInput");

            int iError = ERROR_SUCCESS;
            int iTest = nativeNormalizationIsNormalizedString(
                normalizationForm, ref iError, strInput, strInput.Length);

            switch(iError)
            {
                // Success doesn't need to do anything
                case ERROR_SUCCESS:
                    break;

                // Do appropriate stuff for the individual errors:
                // Only possible value here is ERROR_NO_UNICODE_TRANSLATION
                case ERROR_NO_UNICODE_TRANSLATION:
                    throw new ArgumentException(
                        Environment.GetResourceString("Argument_InvalidCharSequenceNoIndex" ),
                        "strInput");
                case ERROR_NOT_ENOUGH_MEMORY:
                    throw new OutOfMemoryException(
                        Environment.GetResourceString("Arg_OutOfMemoryException"));
                default:
                    throw new InvalidOperationException(
                        Environment.GetResourceString("UnknownError_Num", iError));
            }

            // Bit 1 is true, 0 is false from our return value.
            return ((iTest & 1) == 1);
        }