CODEWITHSUNDEEP
asp.net-mvc-3
Siva Vaddadi
Siva Vaddadi

Reputation: 1

Anonymous Type Parameters in ASP.NET MVC Framework

Can anyone explain how ASP.NET MVC framework retrieve values from anonymous type parameters, such as Html.ActionLink where the parameter representing HTML attributes can be passed in as Anonymous type. I read it uses Reflection internally. I am looking for pseudocode or example to understand better.

Upvotes: 0

Views: 438

Answers (1)

Darin Dimitrov
Darin Dimitrov

Reputation: 1038730

It uses the RouteValueDictionary precious constructor which allows you to convert an anonymous object into a dictionary:

class Program
{
    static void Main()
    {
        var anon = new { foo = "foo value", bar = "bar value" };
        IDictionary<string, object> values = new RouteValueDictionary(anon);
        foreach (var item in values)
        {
            Console.WriteLine("{0}, {1}", item.Key, item.Value);
        }
    }
}

As far as the implementation is concerned you may always take a look at the ASP.NET MVC source code but here are the relevant parts:

public class RouteValueDictionary : IDictionary<string, object>, ICollection<KeyValuePair<string, object>>, IEnumerable<KeyValuePair<string, object>>, IEnumerable
{

    public RouteValueDictionary(object values)
    {
        this._dictionary = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
        this.AddValues(values);
    }

    private void AddValues(object values)
    {
        if (values != null)
        {
            foreach (PropertyDescriptor descriptor in TypeDescriptor.GetProperties(values))
            {
                object obj2 = descriptor.GetValue(values);
                this.Add(descriptor.Name, obj2);
            }
        }
    }

    ...
}

As you can see it uses the TypeDescriptor.GetProperties method to retrieve all properties of the anonymous object and their values afterwards.

Upvotes: 2

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