Question

Working with Asp.Net MVC for quite some time now, but I am stuck on a very strange question. Everytime I create a model I make use of lambda expressions like:

@Html.EditorFor(model=>model.SomeProperty)

Why is Asp.Net MVC using such type of an architecture?

Why cant I just pass in a property using reflection?

Is using lambda expression faster? Because under the hoods what I think is that to get the property name it must be using the reflection.

Answer 1

Lambda > Reflection

Using lambdas you get:

• Design-time, strongly-typed property selectors.
• Refactoring made easy using built-in Visual Studio refactoring tools.

Thanks to lambdas, any API can know a lot of things from the property selector:

• The property type.
• The object of the property.
• Inspect property metadata.

In addition, check the method signature (http://msdn.microsoft.com/en-us/library/ee402949(v=vs.108).aspx):

public static MvcHtmlString EditorFor<TModel, TValue>(
    this HtmlHelper<TModel> html,
    Expression<Func<TModel, TValue>> expression
)

It’s an expression tree rather than a regular lambda. This allows MVC (and again, any API) to manipulate the expression in order to add more behaviors prior to invoking it during run-time, without reflection emit.

Learn more about expression trees:

• http://msdn.microsoft.com/en-us/library/bb397951.aspx