CreateObject fails with error "CreateObject function was not declared"

Question

Using VS2012, I get the error "CreateObject function was not declared" in this line:

        _cMouseIndicator = CreateObject("twsMouseIndicator.clsMouseIndicator")

Does anybody know what is going wrong here? I thought that CreateObject was a part of one of the standard libraries.

Thank you for the help!

Furkan Omay · Accepted Answer · 2014-10-07 23:04:58Z

2

If you add this import:

Imports Microsoft.VisualBasic.Interaction

then CreateObject should work.

CreateObject is a leftover from the classic Visual Basic like VB6, ASP, VBA and VBScript.

You can also achieve the same late-binding with this snippet:

Dim _cMouseIndicator As Object

Dim t As Type = Type.GetTypeFromProgID("twsMouseIndicator.clsMouseIndicator", True)
_cMouseIndicator = Activator.CreateInstance(t)

But it would be painful to invoke methods on this object with InvokeMember calls.

I'd advise you to add the library you want as a reference. Visual Studio should handle the ActiveX COM imports with Interop and you can use your library with the new keyword.

edited Oct 7, 2014 at 23:04

answered Oct 7, 2014 at 22:57

Furkan Omay

1,0671 gold badge11 silver badges22 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Dave Doknjas Over a year ago

In VB, for either option (CreateObject or Activator.CreateInstance) you need to have Option Strict Off. In C#, the 'dynamic' keyword gives you slack on the relevant object, but without tossing the rest of the code in Option Strict Off coding horror land.

Furkan Omay Over a year ago

@DaveDoknjas dynamic is very convenient but if you use InvokeMember, CreateInstance should work even with Option Strict On although it causes my eyes to bleed. A working VB.NET example for the type "SAPI.SpVoice" would be:

SAPI.GetType().InvokeMember("Speak", Reflection.BindingFlags.InvokeMethod, Nothing, SAPI, New Object() {"Hello world!", 0})

Dave Doknjas Over a year ago

Right - I overlooked that. Totally agree on the bleeding eyes.

tmighty Over a year ago

@FurkanOmay Thanks for the advice about adding the library. Unfortunately I can not do this because then VS does not use my class as out-of-proc anymore. I am only able to run my class with a different ProcessID, if I use CreateObject.

tmighty Over a year ago

But I think the Activator approach also works great. Thank you very much!!

Collectives™ on Stack Overflow

CreateObject fails with error "CreateObject function was not declared"

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related