using System;

using System.Linq.Expressions;

using System.Reflection;

using System.Xml;

public class Program

{

    public static void Main()

    {

        XmlDocument xml = new XmlDocument();

​

        // locate the property

        PropertyInfo innerXml = xml

            .GetType()

            .GetProperty(

                "InnerXml");

​

        // ParameterExpression is used to map a value from the caller

        // to the lambda body

        ParameterExpression document = Expression.Parameter(

            xml.GetType());

​

        ParameterExpression content = Expression.Parameter(

            typeof(string));

​

        // define the body of the lambda

        MethodCallExpression body = Expression.Call(

            document,

            innerXml.GetSetMethod(),

            new Expression[]

            {

                content

            });

​

        // Action<in T1, in T2>

​

        // first Type argument of Func definition will be Type of instance object

        // second Type argument of Func definition will be Type of value

​

        Expression<Action<XmlDocument, string>> lambda = Expression.Lambda<Action<XmlDocument, string>>(

​

            // this is going to be the function body/logic

            body,

​

            // this is the parameter list being passed in to the lambda body

​

            // have to use same ParameterExpression instances referenced in

            // expression body definition above to get them to map through Action call

            new ParameterExpression[]

            {

                document,

                content

            });

​

        // create the Action from the lambda

        Action<XmlDocument, string> action = lambda.Compile();

​

        // use Action to set value

        action(

            xml,

            "<document />");

​

        Console.WriteLine(xml.InnerXml);

    }

}