C# Reflection: Get all active assemblies in a solution

creflection

Here's my problem:

I have 2 projects – one 'common' projects with acts like a library with all kinds of support code, and the actual program that uses said project in many of its calls. We'll call these projects "Common" and "Program". They are both in the same solution.

Within "Common", I have a class for common reflection tasks, like creating an instance. If I call GetExecutingAssembly, it gets all the "Common" Types, however when I use GetEntryAssembly I get the "Program" types.

While I certainly could edit the code to work with 2 sets of asm, I'm afraid of a situation where there are more than just 2 projects in the solution – lets say 5 (don't know why, but lets just go there for now), and I'm afraid that calling GetExecutingAssembly and GetEntryAssembly will not get all the Types in the entire program.

Is there something else that i can do to get all the Types in a solution?

Best Answer

Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();

This will get all of the loaded assemblies in the current AppDomain.

As noted in the comments, it's possible to spawn multiple AppDomains, in which case each can have its own assemblies. The immediate advantage to doing so is that you can unload Assemblies by unloading the containing AppDomain.

Related Solutions

Java – reflection and why is it useful

The name reflection is used to describe code which is able to inspect other code in the same system (or itself).

For example, say you have an object of an unknown type in Java, and you would like to call a 'doSomething' method on it if one exists. Java's static typing system isn't really designed to support this unless the object conforms to a known interface, but using reflection, your code can look at the object and find out if it has a method called 'doSomething' and then call it if you want to.

So, to give you a code example of this in Java (imagine the object in question is foo) :

Method method = foo.getClass().getMethod("doSomething", null);
method.invoke(foo, null);

One very common use case in Java is the usage with annotations. JUnit 4, for example, will use reflection to look through your classes for methods tagged with the @Test annotation, and will then call them when running the unit test.

There are some good reflection examples to get you started at http://docs.oracle.com/javase/tutorial/reflect/index.html

And finally, yes, the concepts are pretty much similar in other statically typed languages which support reflection (like C#). In dynamically typed languages, the use case described above is less necessary (since the compiler will allow any method to be called on any object, failing at runtime if it does not exist), but the second case of looking for methods which are marked or work in a certain way is still common.

Update from a comment:

The ability to inspect the code in the system and see object types is not reflection, but rather Type Introspection. Reflection is then the ability to make modifications at runtime by making use of introspection. The distinction is necessary here as some languages support introspection, but do not support reflection. One such example is C++

C# – How to use reflection to call a generic method

You need to use reflection to get the method to start with, then "construct" it by supplying type arguments with MakeGenericMethod:

MethodInfo method = typeof(Sample).GetMethod(nameof(Sample.GenericMethod));
MethodInfo generic = method.MakeGenericMethod(myType);
generic.Invoke(this, null);

For a static method, pass null as the first argument to Invoke. That's nothing to do with generic methods - it's just normal reflection.

As noted, a lot of this is simpler as of C# 4 using dynamic - if you can use type inference, of course. It doesn't help in cases where type inference isn't available, such as the exact example in the question.

Best Answer

Related Solutions

Java – reflection and why is it useful

C# – How to use reflection to call a generic method

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