image - Screen Capture program in VB.NET -

i had created application captures screenshot of desktop screen. works button have used in form. want make thing works automatically using timers whenever try run program nullreferenceexception occur can 1 tell me whats going wrong here.

timercapture interval=5  timersave interval=6 

here code can tell scenario:

public class form1       private sub timercapture_tick(byval sender system.object, byval e system.eventargs) handles timercapture.tick         dim bounds rectangle         dim screenshot system.drawing.bitmap         dim graph graphics         bounds = screen.primaryscreen.bounds         screenshot = new system.drawing.bitmap(bounds.width, bounds.height, system.drawing.imaging.pixelformat.format32bppargb)         graph = graphics.fromimage(screenshot)         graph.copyfromscreen(bounds.x, bounds.y, 0, 0, bounds.size, copypixeloperation.sourcecopy)         picturebox1.image = screenshot     end sub         private sub timersave_tick(byval sender system.object, byval e system.eventargs) handles timersave.tick         me.picturebox1.image.save("d:\\capture.bmp")      end sub      private sub form1_load(byval sender system.object, byval e system.eventargs) handles mybase.load          ' me.windowstate = formwindowstate.minimized          'me.showintaskbar = false      end sub      private sub timerclose_tick(byval sender system.object, byval e system.eventargs) handles timerclose.tick         me.close()      end sub      private sub capture_btn_click(byval sender system.object, byval e system.eventargs) handles capture_btn.click         dim bounds rectangle         dim screenshot system.drawing.bitmap         dim graph graphics         bounds = screen.primaryscreen.bounds         screenshot = new system.drawing.bitmap(bounds.width, bounds.height, system.drawing.imaging.pixelformat.format32bppargb)         graph = graphics.fromimage(screenshot)         graph.copyfromscreen(bounds.x, bounds.y, 0, 0, bounds.size, copypixeloperation.sourcecopy)         picturebox1.image = screenshot     end sub      private sub save_btn_click(byval sender system.object, byval e system.eventargs) handles save_btn.click         me.picturebox1.image.save("d:\\capture.bmp")     end sub end class 

thanks in advance....

i think problem in timersave_tick, if, reason haven't valued me.picturebox1.image in timercapture_tick, throw nullreferenceexception while trying access picturebox1.image.

try modify in such way:

private sub timersave_tick(byval sender system.object, byval e system.eventargs) handles timersave.tick     if(me.picturebox1.image isnot nothing)         me.picturebox1.image.save("d:\\capture.bmp")     end if end sub 

anyway, should able debug under visual studio, see exception thrown..