黑色的空窗户奇维

Question

I made GUI for my program. When I launch app, then it appears empty black screen.

This isn't completed program, but I expect a working application.

Python code: http://pastebin.com/RbMKAd9t
Kivy interface: http://pastebin.com/12eHp0y4

Answer 1

I infer that your kv file is called interface.kv, and you load it only with Builder.load_string. In this case the problem is that Builder.load_string doesn't return anything because there is no root widget definition (ie without the <>) in the file.

Add a root widget definition, or change the build method to return Main() .