Question

I want to loop over all classes which I have added in my project

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

foreach(Assembly a in foo)
{                
    foreach(Type t in a.GetTypes())
    {

    }
}

this is what I tried but I want to exclude the assemblies which are provided by .net, for example “mscorlib”

Answer 1

One common solution would be to filter the assemblies by name, if all of your assemblies have a common prefix (if you have a more or less unique prefix).

var foo = AppDomain.CurrentDomain.GetAssemblies()
                                 .Where(a=>a.FullName.StartsWith("MyProject."));

If you are only interested in some specific types, consider using attributes for your classes, or even add one at assembly level.

Example:

Create an attribute:

[AttributeUsage(AttributeTargets.Assembly)]
public class MyAssemblyAttribute : Attribute { }

add the following to your AssemblyInfo.cs:

[assembly: MyAssemblyAttribute()]

and filter the assemblies you are looking at:

var foo = AppDomain.CurrentDomain
                   .GetAssemblies()
                   .Where(a => a.GetCustomAttributes(typeof(MyAssemblyAttribute), false).Any());

Also you will find at this question interesting. In one answer it is suggested to check the fully qualified name of each assembly, but this is quite tedious, e.g.:

//add more .Net BCL names as necessary
var systemNames = new HashSet<string>
{
    "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089",
    "System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
    ...
};

var isSystemType = systemNames.Contains(objToTest.GetType().Assembly.FullName); 

It’s always easier to mark your assemblies (by name or attribute) than trying to identify which ones are part of the .Net framework.