Reflection - Call constructor with parameters

Question

I read type from loaded assemblies for example:

var someType = loadedAssemblies
            .Where(a => a != null && a.FullName.StartsWith(\"MY.\"         


        

Answer 1

You can make a helper method to get default value of a type:

private static object GetDefaultValue(Type type)
{
    if (type.IsEnum) return type.GetEnumValues().GetValue(0);
    if (type.IsValueType) return Activator.CreateInstance(type);
    return null;
}

Then, you can get default values of the parameters:

var parameters = constructor.GetParameters()
                            .Select(p => GetDefaultValue(p.ParameterType))
                            .ToArray();

And invoke the ConstructorInfo to get the instance:

var obj = constructor.Invoke(parameters);

---

If the constructor's parameters have default values and you want to use them, you can do something like this:

var parameters = constructor
    .GetParameters()
    .Select(p => p.HasDefaultValue ? p.RawDefaultValue : GetDefaultValue(p.ParameterType))
    .ToArray();