How to speed up XML deserialization?

Question

I have the following code snippet

public static object XmlDeserialize(string xml, Type objType)
{
    StringReader stream = null;
    XmlTextReader reader = null;
    try
    {
        XmlSerializer serializer = new XmlSerializer(objType);
        stream = new StringReader(xml); // Read xml data
        reader = new XmlTextReader(stream);  // Create reader
        return serializer.Deserialize(reader);
    }
    finally
    {
        if(stream != null) stream.Close();
        if(reader != null) reader.Close();
    }
}

The object itself was generated using xsd.exe and looks something like this:

/// <remarks/>
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.3038")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)]
[System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)]
public partial class MyObject {

    private DemographicsCriteriaStateStartAge[] startAgesField;

    private DemographicsCriteriaStateEndAge[] endAgesField;

    private DemographicsCriteriaStateFilter[] selectedFiltersField;

    /// <remarks/>
    [System.Xml.Serialization.XmlArrayItemAttribute("StartAge", IsNullable=false)]
    public DemographicsCriteriaStateStartAge[] StartAges {
        get {
            return this.startAgesField;
        }
        set {
            this.startAgesField = value;
        }
    }
    ...

The method is usually called the following:

var obj = (MyObject) XmlDeserialize(someXmlString, typeof(MyObject));

The following line of code always takes a fairly large chunk of time (compared to everything else):

XmlSerializer serializer = new XmlSerializer(objType);

What is going on here, for example. Is it building a deserialization assembly in the background? Why is there a performance problem?

What can I do to improve this performance problem?

Answer 1

, . Visual Studio. . " ", true. YourProject.XmlSerialiser.dll .

, , , - (, - ). Visual Studio 2010 , (.csproj), remove/proxytypes Sgen , sgen.exe .

Answer 2

XmlSerializer , , :

class Foo
{
    private static Dictionary<Type, XmlSerializer> xmls = new Dictionary<Type, XmlSerializer>();

    // ...

    public static object XmlDeserialize(string xml, Type objType)
    {
        StringReader stream = null;
        XmlTextReader reader = null;
        try
        {
            XmlSerializer serializer;
            if(xmls.Contains(objType)) {
                serializer = xmls[objType];
            }
            else {
                serializer = new XmlSerializer(objType);
                xmls[objType] = serializer;
            }           

            stream = new StringReader(xml); // Read xml data
            reader = new XmlTextReader(stream);  // Create reader
            return serializer.Deserialize(reader);
        }
        finally
        {
            if(stream != null) stream.Close();
            if(reader != null) reader.Close();
        }
    }
}