Find Types in All Assemblies

I need to look for specific types in all assemblies in a web site or windows app, is there an easy way to do this? Like how the controller factory for ASP.NET MVC looks across all assemblies for controllers.

Thanks.

Solution 1:

There are two steps to achieve this:

• The AppDomain.CurrentDomain.GetAssemblies() gives you all assemblies loaded in the current application domain.
• The Assembly class provides a GetTypes() method to retrieve all types within that particular assembly.

Hence your code might look like this:

foreach (Assembly a in AppDomain.CurrentDomain.GetAssemblies())
{
    foreach (Type t in a.GetTypes())
    {
        // ... do something with 't' ...
    }
}

To look for specific types (e.g. implementing a given interface, inheriting from a common ancestor or whatever) you'll have to filter-out the results. In case you need to do that on multiple places in your application it's a good idea to build a helper class providing different options. For example, I've commonly applied namespace prefix filters, interface implementation filters, and inheritance filters.

For detailed documentation have a look into MSDN here and here.

Solution 2:

LINQ solution with check to see if the assembly is dynamic:

/// <summary>
/// Looks in all loaded assemblies for the given type.
/// </summary>
/// <param name="fullName">
/// The full name of the type.
/// </param>
/// <returns>
/// The <see cref="Type"/> found; null if not found.
/// </returns>
private static Type FindType(string fullName)
{
    return
        AppDomain.CurrentDomain.GetAssemblies()
            .Where(a => !a.IsDynamic)
            .SelectMany(a => a.GetTypes())
            .FirstOrDefault(t => t.FullName.Equals(fullName));
}

Solution 3:

Easy using Linq:

IEnumerable<Type> types =
            from a in AppDomain.CurrentDomain.GetAssemblies()
            from t in a.GetTypes()
            select t;

foreach(Type t in types)
{
    ...
}