In theory XML should always be portable between different versions of .NET Framework/.NET Core/.NET. But there are always exceptions to the rule.
For example IF you're moving System.Data.DataTables around in XML format, and IF some of those data tables contain columns of type System.Guid, then you're likely in for a surprise! Consider the following example code:
using System;
using System.Data;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
public class Program
{
internal static string SerializeToXml<T>(T input)
{
var writerSettings = new XmlWriterSettings()
{
Encoding = new UTF8Encoding(false),
Indent = true
};
using (var stream = new MemoryStream())
using (var writer = XmlWriter.Create(stream, writerSettings))
{
(new XmlSerializer(typeof(T))).Serialize(writer, input);
return Encoding.UTF8.GetString(stream.ToArray());
}
}
public static void Main()
{
var dt = new DataTable("Name");
dt.Columns.Add("Example", typeof(Guid));
Console.WriteLine(SerializeToXml(dt));
}
}
Unlike most other system types System.Guid gets a version-specific msdata:DataType attribute included in the column definition and that will throw a System.InvalidOperationException: There is an error in XML document (.., ...) wrapping a System.ArgumentException: Column requires a valid DataType when an incompatible runtime attempts to deserialize it.
.NET Framework 4.7.2 output:
<?xml version="1.0" encoding="utf-8"?>
<DataTable>
<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="Name" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="Name">
<xs:complexType>
<xs:sequence>
<xs:element name="Example" msdata:DataType="System.Guid, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" type="xs:string" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataTable>
.NET Core 3.1 output: (yes, it outputs version 4.0.0.0)
<?xml version="1.0" encoding="utf-8"?>
<DataTable>
<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="Name" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="Name">
<xs:complexType>
<xs:sequence>
<xs:element name="Example" msdata:DataType="System.Guid, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e" type="xs:string" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataTable>
.NET 5 output:
.NET 5
<?xml version="1.0" encoding="utf-8"?>
<DataTable>
<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="Name" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="Name">
<xs:complexType>
<xs:sequence>
<xs:element name="Example" msdata:DataType="System.Guid, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e" type="xs:string" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataTable>
.NET 6 output:
<?xml version="1.0" encoding="utf-8"?>
<DataTable>
<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="Name" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="Name">
<xs:complexType>
<xs:sequence>
<xs:element name="Example" msdata:DataType="System.Guid, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e" type="xs:string" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataTable>
.NET 7 output:
<?xml version="1.0" encoding="utf-8"?>
<DataTable>
<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="Name" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="Name">
<xs:complexType>
<xs:sequence>
<xs:element name="Example" msdata:DataType="System.Guid, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e" type="xs:string" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" />
</DataTable>
