Kivy Python函数类和时钟Stu

Question

这主要不是我掌握的面向对象编程，而是涉及时钟函数

我希望我的GUI有一个按钮，启动一个不断更新的功能（使用时钟功能安排）。同时也希望GUI有一个按钮来结束不断更新的功能。（或者有更好的方法来实现这一点？把它放在if语句中？当我按下那个按钮时，这个值会在python端更新吗？）在

import kivy
import sqlite3
import sched, time
import smbus
import time
from Naked.toolshed.shell import execute_js, muterun_js
import os
import signal
import multiprocessing, signal
from kivy.uix.behaviors.button import ButtonBehavior
from kivy.uix.button import Button
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.widget import Widget
from kivy.base import runTouchApp
from kivy.clock import Clock
from kivy.properties import ListProperty
from kivy.properties import ObjectProperty
from kivy.vector import Vector
from kivy.core.window import Window
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.event import EventDispatcher
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.stacklayout import StackLayout
from kivy.core.image import Image
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition, WipeTransition, SwapTransition

bus = smbus.SMBus(1)
address = 0x04

p = multiprocessing.Process(target = muterun_js,args=('iss_telemetry.js',)) #might delete this

conn = sqlite3.connect('iss_telemetry.db') #sqlite database call change to include directory
c = conn.cursor() 
val = ""

def StringToBytes(val):
    retVal = []
    for c in val:
            retVal.append(ord(c))
    return retVal

class MainScreen(Screen):
    def __init__(self, **kwargs):
        super(MainScreen, self).__init__(**kwargs)

class CalibrateScreen(Screen):
    pass

class ManualControlScreen(Screen):
    def __init__(self, **kwargs):
        super(ManualControlScreen, self).__init__(**kwargs)

    def i2cWrite(self, *args):
        bus.write_i2c_block_data(address, 0, StringToBytes(*args))

class MimicScreen(Screen, EventDispatcher):
    def __init__(self, **kwargs):
        super(MimicScreen, self).__init__(**kwargs)

class MainScreenManager(ScreenManager):
    pass

class MyButton(Button):
    pass

def point_inside_polygon(x, y, poly):
    ...

class TriangleButton(ButtonBehavior, Widget):
    ...

class MainApp(App):

    event = Clock.schedule_interval(self.update_labels, 1)
    event()
    event.cancel()

    def build(self):
        self.mimic_screen = MimicScreen(name = 'mimic')
        root = ScreenManager(transition=WipeTransition())
        root.add_widget(MainScreen(name = 'main'))
        root.add_widget(CalibrateScreen(name = 'calibrate'))
        root.add_widget(self.mimic_screen)
        root.add_widget(ManualControlScreen(name = 'manualcontrol'))
        root.current= 'main'

       # Clock.schedule_interval(self.update_labels, 1)
        return root

    def clockStart(self):
        event()

    def clockEnd(self):
        event.cancel()   

    def i2cWrite(self, *args):
        bus.write_i2c_block_data(address, 0, StringToBytes(*args))

    def update_labels(self, dt):
        c.execute('select two from telemetry')
        values = c.fetchall()
        psarj = values[0]
        ssarj = values[1]
        ptrrj = values[2]
        strrj = values[3]
        beta1b = values[4]
        beta1a = values[5]
        beta2b = values[6]
        beta2a = values[7]
        beta3b = values[8]
        beta3a = values[9]
        beta4b = values[10]
        beta4a = values[11]
        aos = values[12]
        self.mimic_screen.ids.psarjvalue.text = str(psarj[0])[:-5]
        self.mimic_screen.ids.ssarjvalue.text = str(ssarj[0])[:-5]
        self.mimic_screen.ids.ptrrjvalue.text = str(ptrrj[0])[:-5]
        self.mimic_screen.ids.strrjvalue.text = str(strrj[0])[:-5]
        self.mimic_screen.ids.beta1bvalue.text = str(beta1b[0])[:-5]
        self.mimic_screen.ids.beta1avalue.text = str(beta1a[0])[:-5]
        self.mimic_screen.ids.beta2bvalue.text = str(beta2b[0])[:-5]
        self.mimic_screen.ids.beta2avalue.text = str(beta2a[0])[:-5]
        self.mimic_screen.ids.beta3bvalue.text = str(beta3b[0])[:-5]
        self.mimic_screen.ids.beta3avalue.text = str(beta3a[0])[:-5]
        self.mimic_screen.ids.beta4bvalue.text = str(beta4b[0])[:-5]
        self.mimic_screen.ids.beta4avalue.text = str(beta4a[0])[:-5]



Builder.load_string('''
#:kivy 1.8
#:import kivy kivy
#:import win kivy.core.window
<MainScreen>:
    ...
<ManualControlScreen>:
    ...     
<CalibrateScreen>:
    ...
<MimicScreen>:
    name: 'mimic'
    FloatLayout:
        psarjvalue: psarjvalue
        id: mimicscreenlayout
        Image:
            source: 'iss1.png'
            allow_stretch: True
            keep_ratio: False
        ...
        Button:
            id: mimicstartbutton
            size_hint: 0.25,0.1
            pos_hint: {"x": 0.07, "y": 0.6}
            text: 'MIMIC'
            disabled: False
            font_size: 30
            on_release: telemetrystatus.text = 'Sending Telemetry...'
            on_release: app.clockStart()
            on_release: mimicstopbutton.disabled = False
            on_release: mimicstartbutton.disabled = True
        Button:
            id: mimicstopbutton
            size_hint: 0.25,0.1
            pos_hint: {"x": 0.07, "y": 0.4}
            text: 'Stop'
            disabled: True
            font_size: 30
            on_release: telemetrystatus.text = 'I2C Stopped'
            on_release: app.clockStop()
            on_release: mimicstopbutton.disabled = True
            on_release: mimicstartbutton.disabled = False
        Button:
            size_hint: 0.3,0.1
            pos_hint: {"Left": 1, "Bottom": 1}
            text: 'Return'
            font_size: 30
            on_release: app.clockStop()
            on_release: root.manager.current = 'main'

<TriangleButton>:
    ...

''')

if __name__ == '__main__':
    MainApp().run()

以下是相关课程：

^{pr2}$

这是kv规范的相关部分（简化版）

<MimicScreen>:
    name: 'mimic'
    FloatLayout:
        ...
        Button:
            ...
            on_release: app.clockStart()
        Button:
            ...
            on_release: app.clockStop()
        Button:
            ...
            on_release: app.clockStop()

所以当我试着这样运行它时，它会抱怨不知道事件是什么。我觉得在类函数之外声明它会使整个类都可以使用它。在

建议？建议？谢谢你的帮助

Answer 1

它在抱怨，因为您需要将一个变量定义为global，才能在一个函数中使用它，而这个函数没有传递给或者使用self.varname将它附加到对象。此外，您正在创建事件，然后在调用build之前立即取消它。在

您应该有一个按钮，它有一个方法on_release，该方法用Clock启动schedule_interval函数调用。按下此按钮后应禁用。第二个按钮将使用cancel取消计划。在

下面是一个基本的工作示例：

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.clock import Clock

class MyLayout(BoxLayout):
    pass

class StartButton(Button):
    def on_release(self):
        self.event_handle = Clock.schedule_interval(self.clocks_are_fun,0.5)
        self.disabled = True
    def clocks_are_fun(self,dt):
        self.parent.parent.ids.mylabel.text = 'Frames: ' + str(Clock.frames)
    def closing_time(self):
        self.event_handle.cancel()

class StopButton(Button):
    def on_release(self):
        self.parent.parent.ids.button1.closing_time()
        self.parent.parent.ids.button1.disabled = False

class MyApp(App):
    def build(self):
        boxyFunTime = MyLayout()
        return boxyFunTime

if __name__ == '__main__':
    MyApp().run()

以及.kv文件：

^{pr2}$