Let's talk about kivy's EventDispatcher here:
The codes I have tried here:
codes here:
from kivy.event import EventDispatcher
class MyEventDispatcher(EventDispatcher):
def __init__(self, **kwargs):
self.register_event_type('on_test')
super(MyEventDispatcher, self).__init__(**kwargs) def do_something(self, value):
# when do_something is called, the 'on_test' event will be
# dispatched with the value
self.dispatch('on_test', value) def on_test(self, *args):
print "I am dispatched", args
Then I did this:
def my_callback(value, *args):
print "Hello, I got an event!", args ev = MyEventDispatcher()
ev.bind(on_test=my_callback)
ev.do_something('test')
Python returned me with this:
the method "my_callback" is bounded to "on_test" of the instance "ev"
After binding, event triggers event
从上面的输出看到，执行了ev.do_something 后
Now if we don't bind the "my_callback", and just do
ev.do_something('test')
let's see what we can get.
由于没有用到dispatch 没有被先事先bind到，所以就比较难受地的给出了报错。ev.do_something dispatch 不到 on_test 上面了。所以要事先声明一下就是bind一下。