What is the most efficient way to get the default constructor (i.e. instance constructor with no parameters) of a System.Type?
I was thinking something along the lines of the code below but it seems like there should be a simplier more efficient way to do it.
Type type = typeof(FooBar)
BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance;
type.GetConstructors(flags)
.Where(constructor => constructor.GetParameters().Length == 0)
.First();
If you actually need the ConstructorInfo object, then see Curt Hagenlocher's answer.
On the other hand, if you're really just trying to create an object at run-time from a System.Type, see System.Activator.CreateInstance -- it's not just future-proofed (Activator handles more details than ConstructorInfo.Invoke), it's also much less ugly.
you would want to try FormatterServices.GetUninitializedObject(Type) this one is better than Activator.CreateInstance
However , this method doesn't call the object constructor , so if you are setting initial values there, this won't work Check MSDN for this thing http://msdn.microsoft.com/en-us/library/system.runtime.serialization.formatterservices.getuninitializedobject.aspx
there is another way here http://www.ozcandegirmenci.com/post/2008/02/Create-object-instances-Faster-than-Reflection.aspx
however this one fails if the object have parametrize constructors
Hope this helps