your application.
if you create a PhotoImage under one Tk instance, you cannot access
it from other instances.
to fix this, make sure you only use one Tk instance (use Toplevel to create
new toplevel windows), or make sure that you create the image under the
same instance as the widget you're going to use it in. the easiest way to
do
this is to pass in a master keyword argument to the PhotoImage constructor:
photo = PhotoImage(..., master=myroot)
button = Button(myroot, ...)
button.photo = photo # keep a reference
對於PhotoImage對象只能在壹個線程下使用，在主要模塊中已經用TK()啟動壹個線程，再在次模塊中啟動壹個線程就不能調用PhotoImage對象。所以開啟希望開啟次窗口可采用用frame或者toplevel去代替。
以上屬於個人理解，錯誤望指點。