因此,我想从Arduino
到serial port
读取数据,并将读取的数据更新为标签文本以显示。当我只有简单的代码可以读取和更新时,它可以工作,但是当我添加ScreenManager
和Screen
时,它将停止更新文本。
最终我将需要根据接收到的数据制作不同的动画,这更多地是在测试此功能是否有效
预先感谢!
这是我的完整代码
import os
os.environ['KIVY_GL_BACKEND'] ='gl'
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.properties import (NumericProperty, StringProperty, ReferenceListProperty, ObjectProperty, ListProperty)
from kivy.clock import Clock
from kivy.vector import Vector
from kivy.core.text import LabelBase
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
LabelBase.register(name='Sans',fn_regular="Sansation-Regular.ttf")
import serial
kivy = Builder.load_string("""
#:import FadeTransition kivy.uix.screenmanager.FadeTransition
<MyManager>:
transition: FadeTransition()
MainScreen:
OperationScreen:
<MainScreen>:
name: 'main'
Label:
text: 'Welcome'
font_size: 40
on_touch_up : app.root.current = 'operation'
Label:
text: 'dafault'
font_size: 20
pos: -200,-100
id: data_label
<OperationScreen>:
name: 'operation'
Label:
text: 'Youre in'
font_size: 40
""")
class OperationScreen(Screen):
pass
class MainScreen(Screen):
def __init__(self,**kwargs):
super(MainScreen,self).__init__(**kwargs)
def Read(self,dt):
Clock.unschedule(self.Read)
data = arduino.readline()
if data != '':
self.ids.data_label.text = data
Clock.schedule_once(self.Read)
pass
class MyManager(ScreenManager):
pass
class mainApp(App):
Main = MainScreen()
def build(self):
Clock.schedule_once(self.Main.Read)
return MyManager()
if __name__ == '__main__':
try:
arduino = serial.Serial('/dev/ttyACM0', 9600, timeout=1)
except:
print("failed to connect")
mainApp().run()
我希望带有“默认”文本的标签会相应地更改,但只是被“默认”冻结了
答案 0 :(得分:1)
您的应用运行时,有两个class MainScreen
的实例。一个已在kv文件中实例化。另一个是手动实例化的,位于Main = MainScreen()
中的class mainApp
。
方法Read()
的调度是在手动创建的实例Main = MainScreen()
中创建的,没有与此相关的模态视图。
id: main_screen
添加MainScreen:
Main = MainScreen()
中的class mainApp
class MyManager()
实现构造函数class mainApp
移到class MyManager()
的构造函数中Clock.create_trigger()
而不是Clock.schedule_once()
event.cancel()
或Clock.unschedule(event)
import os
os.environ['KIVY_GL_BACKEND'] = 'gl'
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.properties import (NumericProperty, StringProperty, ReferenceListProperty, ObjectProperty, ListProperty)
from kivy.clock import Clock
from kivy.vector import Vector
from kivy.core.text import LabelBase
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
# LabelBase.register(name='Sans', fn_regular="Sansation-Regular.ttf")
import serial
kivy = Builder.load_string("""
#:import FadeTransition kivy.uix.screenmanager.FadeTransition
<MyManager>:
transition: FadeTransition()
MainScreen:
id: main_screen
OperationScreen:
<MainScreen>:
name: 'main'
Label:
text: 'Welcome'
font_size: 40
on_touch_up : app.root.current = 'operation'
Label:
text: 'dafault'
font_size: 20
pos: -200,-100
id: data_label
<OperationScreen>:
name: 'operation'
Label:
text: 'Youre in'
font_size: 40
""")
class OperationScreen(Screen):
pass
class MainScreen(Screen):
def Read(self, dt):
data = str(dt)
# data = arduino.readline()
if data != '':
self.ids.data_label.text = data
self.manager.event_trigger()
else:
self.manager.event_trigger.cancel()
class MyManager(ScreenManager):
event_trigger = ObjectProperty(None)
def __init__(self, **kwargs):
super(MyManager, self).__init__(**kwargs)
self.event_trigger = Clock.create_trigger(self.ids.main_screen.Read)
self.event_trigger()
class mainApp(App):
def build(self):
return MyManager()
if __name__ == '__main__':
# try:
# arduino = serial.Serial('/dev/ttyACM0', 9600, timeout=1)
# except:
# print("failed to connect")
mainApp().run()