Read typed objects from XML using known XSD

Steven_W picture Steven_W · Feb 19, 2010 · Viewed 41.3k times · Source

I have the following (as an example) XML file and XSD.

<?xml version="1.0" encoding="utf-8" ?>
<foo>
  <DateVal>2010-02-18T01:02:03</DateVal>
  <TimeVal>PT10H5M3S</TimeVal>
</foo>

and

version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="foo">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="DateVal" type="xs:dateTime" />
        <xs:element name="TimeVal" type="xs:duration" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

Then the following C# code:

  static void Main(string[] args)
  {
     XmlDocument xd = new XmlDocument();
     XmlSchema xs;
     using (var fs = File.OpenRead(FilePath + "SimpleFields.xsd"))
     {
        xs = XmlSchema.Read(fs, null);
     }

     xd.Schemas.Add(xs);
     xd.Load((FilePath + "SimpleFields.xml"));
     xd.Validate(null);

     var el_root = xd.DocumentElement;

     var el_date = (XmlElement)el_root.SelectSingleNode("./DateVal");
     //WANTED: el_date.Value = 2010-02-18 01:02:03 (as a DateTime Object)
     //ACTUAL: el_date.InnerText="2010-02-18T01:02:03"

     var el_duration = (XmlElement)el_root.SelectSingleNode("./TimeVal");
     //WANTED: el_date.Value = 10 hours, 5 minutes, 3 seconds (as a TimeSpan Object)
     //ACTUAL: el_date.InnerText="PT10H5M3S"

     Console.WriteLine("DONE");
     Console.ReadLine();
  }

How can I read the data as strongly typed objects ?

I will be targetting a WindowsMobile device, but this shouldn't need to affect the answer too much. (can be .NET 2.0 or 3.5 ... Not sure if Sstem.Xml.Linq will help or not)

Answer

marc_s picture marc_s · Feb 19, 2010

You need to do two steps:

1) Take your XML schema file and run it through the xsd.exe utility (which comes with the Windows SDK - it's in C:\Program Files\Microsoft SDKs\Windows\v6.0A\Bin\ or some similar path. This can turn the XSD file into a C# class:

xsd /c yourfile.xsd

This should give you a file yourfile.cs which contains a class representing that XML schema.

2) Now, armed with that C# class, you should be able to just deserializing the XML file into an instance of your new object:

XmlSerializer ser = new XmlSerializer(typeof(foo));

string filename = Path.Combine(FilePath, "SimpleFields.xml");

foo myFoo = ser.Deserialize(new FileStream(filename, FileMode.Open)) as foo;

if (myFoo != null)
{
   // do whatever you want with your "foo"
}

That's about as simple as it gets! :-)