Instansitate a class by String

[CJ Taylor]

I think I've seen this somewhere, but I cannot remember how to initialze a
class by a string.

That is, I have a class(Component ) that I want to initialize on the fly. It
is derived from a base component I created.

So basically I have.

Public class myDerivedCompon ent
inherits myBaseComponent

.... stuff ...

End Class

and in another code I want to have

dIm myString as String = "myDerivedCompo nent"

Dim myD as myBaseComponent

myD.InstanceOf (myString)

Hopefully this makes sense.

-CJ

[CJ Taylor]

Nevermind found it.

For thsoe that want the answer, its in the Activator class. (System
namespace).

I'll let you know how it goes.

-CJ
"CJ Taylor" <ct*****@morton welding.com> wrote in message
news:u8******** ******@TK2MSFTN GP09.phx.gbl...

I think I've seen this somewhere, but I cannot remember how to initialze a
class by a string.

That is, I have a class(Component ) that I want to initialize on the fly. It is derived from a base component I created.

So basically I have.

Public class myDerivedCompon ent
inherits myBaseComponent

... stuff ...

End Class

and in another code I want to have

dIm myString as String = "myDerivedCompo nent"

Dim myD as myBaseComponent

myD.InstanceOf (myString)

Hopefully this makes sense.

-CJ

[CJ Taylor]

I was looking into that, but it seemed to much since the method I was
calling was within the Current Executing Assembly.

You would have to work here to understand the weirdness of the situation.
=-)

<bu********@yah oo.com> wrote in message
news:01******** *************** *****@phx.gbl.. .

Well, I've done something like that in a differnt way.

I get all Assembly, Class and method on the fly and
execute it.
NOTE: to use "LoadWithPartia lName" you need u'r assembly
in the GAC.

'Load the DLL
objRef =
System.Reflecti on.Assembly.Loa dWithPartialNam e(strDLLName)
If objRef Is Nothing Then Throw New
Exception("Asse mbly : '" & strDLLName & "' could not be
loaded.")
'Instansiate the Class
objInstance = objRef.CreateIn stance
(strClassName)
If objInstance Is Nothing Then Throw New
Exception("Clas s : '" & strClassName & "' could not be
instantiated.")
'Call the Function
CallByName(objI nstance, strMethodName,
CallType.Method , Object)

-----Original Message-----
Nevermind found it.

For thsoe that want the answer, its in the Activator

class. (System

namespace).

I'll let you know how it goes.

-CJ
"CJ Taylor" <ct*****@morton welding.com> wrote in message
news:u8******* *******@TK2MSFT NGP09.phx.gbl.. .

I think I've seen this somewhere, but I cannot remember how to initialze a class by a string.

That is, I have a class(Component ) that I want to

initialize on the fly.

It

is derived from a base component I created.

So basically I have.

Public class myDerivedCompon ent
inherits myBaseComponent

... stuff ...

End Class

and in another code I want to have

dIm myString as String = "myDerivedCompo nent"

Dim myD as myBaseComponent

myD.InstanceOf (myString)

Hopefully this makes sense.

-CJ

.

[CJ Taylor]

Ok, so Activator isn't working th eway I want to (I could be doing something
wrong)

Here is my current code

Public Function CreateEosBase(B yVal sType As String) As EOSBaseComponen t

Dim tType As System.Type

Dim _EOSBase As EOSBaseComponen t

Try

tType = System.Type.Get Type(sType)

_EOSBase = CType(System.Ac tivator.CreateI nstance(tType), EOSBaseComponen t)

Return _EOSBase

Catch ex As Exception

Console.WriteLi ne("Error:" & Me.GetType.ToSt ring() & " " & ex.Message)

End Try

End Function

And type keeps coming back NullReferenceEx ception

Ideas?

CJ

<bu********@yah oo.com> wrote in message
news:01******** *************** *****@phx.gbl.. .

Well, I've done something like that in a differnt way.

I get all Assembly, Class and method on the fly and
execute it.
NOTE: to use "LoadWithPartia lName" you need u'r assembly
in the GAC.

'Load the DLL
objRef =
System.Reflecti on.Assembly.Loa dWithPartialNam e(strDLLName)
If objRef Is Nothing Then Throw New
Exception("Asse mbly : '" & strDLLName & "' could not be
loaded.")
'Instansiate the Class
objInstance = objRef.CreateIn stance
(strClassName)
If objInstance Is Nothing Then Throw New
Exception("Clas s : '" & strClassName & "' could not be
instantiated.")
'Call the Function
CallByName(objI nstance, strMethodName,
CallType.Method , Object)

-----Original Message-----
Nevermind found it.

For thsoe that want the answer, its in the Activator

class. (System

namespace).

I'll let you know how it goes.

-CJ
"CJ Taylor" <ct*****@morton welding.com> wrote in message
news:u8******* *******@TK2MSFT NGP09.phx.gbl.. .

I think I've seen this somewhere, but I cannot remember how to initialze a class by a string.

That is, I have a class(Component ) that I want to

initialize on the fly.

It

is derived from a base component I created.

So basically I have.

Public class myDerivedCompon ent
inherits myBaseComponent

... stuff ...

End Class

and in another code I want to have

dIm myString as String = "myDerivedCompo nent"

Dim myD as myBaseComponent

myD.InstanceOf (myString)

Hopefully this makes sense.

-CJ

.

[Fergus Cooney]

Hi CJ,

There's a post in the languages.cshar p newsgroup, "opening form by
name", which uses Reflection to invoke the constructor of the class from
which you want an instance. It allows you to pass parameters, if necessary.

Regards,
Fergus