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    copied!<p>If you're on .Net 4, you could use the new <code>Expression</code> types (that were added to support <code>dynamic</code>), to create an expression that assigns the properties, compile it to a delegate once, and call that repeatedly. The performance should be comparable with using Reflection.Emit.</p> <pre><code>class ObjectFiller&lt;T&gt; { private static Func&lt;IDictionary&lt;string, object&gt;, T&gt; FillerDelegate; private static void Init() { var obj = Expression.Parameter(typeof(T), "obj"); var valuesDictionary = Expression.Parameter(typeof(IDictionary&lt;string, object&gt;), "values"); var create = Expression.Assign( obj, Expression.Call(typeof(Activator), "CreateInstance", new[] { typeof(T) })); var properties = typeof(T).GetProperties(); var setters = Expression.Block(properties.Select(p =&gt; CreateSetter(p, obj, valuesDictionary))); var methodBody = Expression.Block(typeof(T), new[] { obj }, create, setters, obj); var fillerExpression = Expression.Lambda&lt;Func&lt;IDictionary&lt;string, object&gt;, T&gt;&gt;(methodBody, valuesDictionary); FillerDelegate = fillerExpression.Compile(); } static Expression CreateSetter(PropertyInfo property, Expression obj, Expression valuesDictionary) { var indexer = Expression.MakeIndex( valuesDictionary, typeof(IDictionary&lt;string, object&gt;).GetProperty("Item", new[] { typeof(string) }), new[] { Expression.Constant(property.Name) }); var setter = Expression.Assign( Expression.Property(obj, property), Expression.Convert(indexer, property.PropertyType)); var valuesContainsProperty = Expression.Call( valuesDictionary, "ContainsKey", null, Expression.Constant(property.Name)); var condition = Expression.IfThen(valuesContainsProperty, setter); return condition; } public T FillObject(IDictionary&lt;string, object&gt; values) { if (FillerDelegate == null) Init(); return FillerDelegate(values); } } </code></pre> <p>You could do something very similar in .Net 3 too, using the <code>Expression</code> version of object initializers.</p>
 

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