using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Xml.Serialization;

using System.Xml.Schema;

using System.Xml;

using System.IO;

using System.Diagnostics;

using System.Collections.ObjectModel;

using System.Threading;

using System.ComponentModel;

using System.Xml.Linq;

using System.Reflection;

using System.Xml.XPath;

​

using NUnit.Framework; //NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/58274413/accessing-schema-information-during-xml-validation

​

    public class TestClass

    {

        public static void Test()

        {

            FixXml(GetXml());

        }

        //Taken from https://docs.microsoft.com/en-us/dotnet/api/system.xml.schema.extensions.getschemainfo?view=netframework-4.8#System_Xml_Schema_Extensions_GetSchemaInfo_System_Xml_Linq_XElement_

        //with an added null check:

        static void DumpInvalidNodes(XElement el)  

        {  

            if (el.GetSchemaInfo().Validity != XmlSchemaValidity.Valid)  

                Console.WriteLine("Invalid Element {0}",  

                    el.AncestorsAndSelf()  

                    .InDocumentOrder()  

                    .Aggregate("", (s, i) => s + "/" + i.Name.ToString()));  

            foreach (XAttribute att in el.Attributes())  

            {

                var si = att.GetSchemaInfo();

                // MUST CHECK FOR NULL HERE

                // Because w3 standard attributes like xmlns:xsi will have null SchemaInfo

                // when not included in the schema, rather than being reported as Invalid.

                if (si != null && si.Validity != XmlSchemaValidity.Valid)  

                    Console.WriteLine("Invalid Attribute {0}",  

                        att  

                        .Parent  

                        .AncestorsAndSelf()  

                        .InDocumentOrder()  

                        .Aggregate("",  

                            (s, i) => s + "/" + i.Name.ToString()) + "/@" + att.Name.ToString()  

                        );  

            }

            foreach (XElement child in el.Elements())  

                DumpInvalidNodes(child);  

        }  

        public static void FixXml(string xmlDoc)

        {

            XDocument doc = XDocument.Parse(xmlDoc);

​

            XmlSchemaSet schema = new XmlSchemaSet();

            using (var sr = new StringReader(GetXsd()))

            using (var xmlReader = XmlReader.Create(sr))

            {

                schema.Add("", xmlReader);

            }

            schema.Compile();

​

            var errors = new List<XmlSchemaValidationException>();

​

            ValidationEventHandler callback = (sender, args) =>

            {

                var exception = (args.Exception as XmlSchemaValidationException);

                if (exception != null)

                {

                    errors.Add(exception);

                }

            };          

​

            doc.Validate(schema, callback, true);           

            foreach (var exception in errors)

            {

                // Handle the exception itself.

                Console.WriteLine(exception);

            }

            if (errors.Count > 0)

            {

                // If there were any errors, traverse the entire document looking for invalid nodes:

                DumpInvalidNodes(doc.Root);

            }

        }

        // XML and Schema from 

        //https://www.w3schools.com/xml/schema_example.asp

        //

        static string GetXml()

        {

            var xml = @"<shiporder numericvalue=""not a numeric value"" stringvalue=""ok"" unexpectedAttribute=""unexpected"" xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"">

  <orderperson>John Smith</orderperson>

  <shipto>

    <address>Langgt 23</address>

    <city>4000 Stavanger</city>

    <country>Norway</country>

  </shipto>

  <item>

    <title>Hide your heart</title>

    <price>9.90</price>

  </item>

</shiporder>";

            return xml;

        }

        static string GetXsd()

        {

            var xsd = @"<xs:schema xmlns:xs=""http://www.w3.org/2001/XMLSchema"">

​

<!-- definition of simple elements -->

<xs:element name=""orderperson"" type=""xs:string""/>

<xs:element name=""name"" type=""xs:string""/>

<xs:element name=""address"" type=""xs:string""/>

<xs:element name=""city"" type=""xs:string""/>

<xs:element name=""country"" type=""xs:string""/>

<xs:element name=""title"" type=""xs:string""/>

<xs:element name=""note"" type=""xs:string""/>

<xs:element name=""quantity"" type=""xs:positiveInteger""/>

<xs:element name=""price"" type=""xs:decimal""/>

​

<!-- definition of attributes -->

<xs:attribute name=""orderid"" type=""xs:string""/>

<xs:attribute name=""numericvalue"" type=""xs:long""/>

<xs:attribute name=""stringvalue"" type=""xs:string""/>

​

<!-- definition of complex elements -->

<xs:element name=""shipto"">

  <xs:complexType>

    <xs:sequence>

      <xs:element ref=""name""/>

      <xs:element ref=""address""/>

      <xs:element ref=""city""/>

      <xs:element ref=""country""/>

    </xs:sequence>

  </xs:complexType>

</xs:element>

​

<xs:element name=""item"">

  <xs:complexType>

    <xs:sequence>

      <xs:element ref=""title""/>

      <xs:element ref=""note"" minOccurs=""0""/>

      <xs:element ref=""quantity""/>

      <xs:element ref=""price""/>

    </xs:sequence>

  </xs:complexType>

</xs:element>

​

<xs:element name=""shiporder"">

  <xs:complexType>

    <xs:sequence>

      <xs:element ref=""orderperson""/>

      <xs:element ref=""shipto""/>

      <xs:element ref=""item"" maxOccurs=""unbounded""/>

    </xs:sequence>

    <xs:attribute ref=""orderid"" use=""required""/>

    <xs:attribute ref=""numericvalue"" use=""required""/>

    <xs:attribute ref=""stringvalue"" use=""required""/>

  </xs:complexType>

</xs:element>

​

</xs:schema>";

            return xsd;

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​