.net - Catch block not catching exception -

i have child form throwing applicationexception in load event handler (intentionally testing purposes). parent form wraps childform.show() method in try...catch ex exception block. catch block displays message , closes child form. works expected when debugged in visual studio 2008 (.net 3.5 sp1). however, when run outside of visual studio, catch block seems missed , unhandled exception occurs. idea why is?

thank you.

example code:

public class form1      private sub button1_click(byval sender system.object, byval e system.eventargs) handles button1.click         dim f2 form2          f2 = new form2          try             messagebox.show("opening form 2")             f2.showdialog()         catch ex exception             f2.close()             messagebox.show("form 2 closed.")         end try     end sub  end class  public class form2      private sub form2_load(byval sender system.object, byval e system.eventargs) handles mybase.load         throw new applicationexception("test form_load")     end sub      public sub new()          ' call required windows form designer.         initializecomponent()          ' add initialization after initializecomponent() call.     end sub  end class 

stack trace:

  system.applicationexception:  test form_load   @ windowsapplication1.form2.form2_load(object sender, eventargs e)  in unhandledexceptiontest2\windowsapplication1\form2.vb  system.windows.forms.form.onload(eventargs e)  system.windows.forms.form.oncreatecontrol()  system.windows.forms.control.createcontrol(boolean fignorevisible)  system.windows.forms.control.createcontrol()  system.windows.forms.control.wmshowwindow(message& m)    @  system.windows.forms.control.wndproc(message&> m)    @  system.windows.forms.scrollablecontrol.wndproc(message&> m)    @  system.windows.forms.containercontrol.wndproc(message&> m)    @  system.windows.forms.form.wmshowwindow(message&> m)    @  system.windows.forms.form.wndproc(message&> m)    @  system.windows.forms.control.controlnativewindow.onmessage(message&> m)    @  system.windows.forms.control.controlnativewindow.wndproc(message&> m)    @  system.windows.forms.nativewindow.callback(intptr hwnd, int32 msg, intptr wparam, intptr  lparam) 

the form.load event behaves same way other events in windows forms. dispatched message loop, in case when windows sends wm_showwindow message. there exception handler in message loop prevents uncaught exception terminating message loop. exception handler raises application.threadevent event. default event handler displays unhandled exception dialog.

long story short, cannot catch exception raised in load event in button click handler. other catching , handling exceptions in load event handler itself, hard right, i'd recommend add public method form. initialize(). move code load event method. call initialize() after calling show() method, exceptions yours catch.