vb.net - Show single instance of form in other project -

i have multiproject solution 1 project "main", startup project.
project starting forms in other projects referenced in startup project.

problem can start forms instances this:

    dim ka new otherproject.frm_thatform     ka         .bringtofront()         .show(me)     end 

that opens new "thatform" every time to start "thatform" single instance every time , "thatform" comes front.

how that?

i try this:

dim ka otherproject.frm_thatform ka     .bringtofront()     .show(me) end 

... don't work (object reference not set instance of object).

the trick not dim form , use shared object.

otherproject.frm_thatform.show() otherproject.frm_thatform.bringtofront() 

as long dont close window can call same way dimmed object.

instead of ka type otherproject.frm_thatform

as close window loose in it.

edit: apparently works forms inside project. bad :(

what need instead keep list of forms inside main project.

make sure give form name, , when click button open form loop through list find set name.

something this:

 private formlist new list(of form) private sub button2_click(sender system.object, e system.eventargs) handles button2.click     dim theform form = nothing     each f form in formlist         if f.name = "selected form name"             theform = f         end if     next     if theform nothing         theform = new otherproject.frm_thatform()         theform.name = "selected form name"         formlist.add(theform)     end if end sub