Entity factory

[Andrus]

I need to create Factory() method which creates entity objects from
string type names ( e.q. "Customer", "Product" ) for 3.5 WinForms Linq
application.

I tried code below but got error shown in comment.

How to fix this code?
How to create constructor from string type name and call it
using reflection or any other solution ?

Andrus.


class TestApplication {

static void Main() {
object Customer = Factory("Customer");
object Product = Factory("Product");
}

static object Factory(string typeName) {
Type t = Type.GetType(typeName);
// error: type expected.
return new <t>();
}
}

class Customer { public string Name { get; set; } }

class Product { public string Code { get; set; } }

 

[Arne Vajhøj]

I need to create Factory() method which creates entity objects from
string type names ( e.q. "Customer", "Product" ) for 3.5 WinForms Linq
application.

I tried code below but got error shown in comment.

How to fix this code?
How to create constructor from string type name and call it
using reflection or any other solution ?

static object Factory(string typeName) {
Type t = Type.GetType(typeName);
// error: type expected.
return new <t>();
}

Try:

Assembly.Load("YournAssembly").CreateInstance("YourClass")

or:

Assembly.GetExecutingAssembly().CreateInstance("YourClass")

Arne

 

[Marc Gravell]

Since you are using 3.5, and assuming your "Type t =
Type.GetType(typeName);" line works (i.e. t is non-null), then note
that I posted some factory Type extension code the other day that is
significantly quicker than reflection, and allows access to
parameterised ctors; it also makes it easy to work with different
interface/base-classes without fuss:

http://groups.google.co.uk/group/mi....csharp/browse_thread/thread/b5d5a729ace312ad

In this particular case, you might choose to find your types ahead of
time and throw the functions in a Dictionary<string,Func<object*>>, so
you can use object obj = factory["Customer"]();

Just a thought. Of course, simple CreateInstance() may do everything
you need...

*=replace object with some common base-class/interface if you like.

Marc