无法获取小部件以更新其大小

时间:2018-10-23 20:19:10

标签: python user-interface kivy kivy-language

我一般来说对kivy和编程还很陌生,并且我的代码有问题。我将其简化了很多,以尝试解决根本问题,但它似乎仍无法正常工作。基本上,该kivy文件应该产生一个橙色正方形,然后将正方形的大小更改为COM7传感器生成的整数值。到目前为止,在启动​​时会生成一个正方形,并且传感器确实已成功将整数值传递给python。我尝试更改NumericProperty“ first_rect”的值,但是无论我如何重新定义first_rect,它的值都不会改变,矩形的大小也不会改变。我感觉有一些非常小而直接的缺失,但是我不确定是什么。

任何帮助将不胜感激!

.py文件

import serial
import time 
from functools import partial
from kivy.uix.widget import Widget
from kivy.app import App 
#kivy.require("1.10.0")
from kivy.clock import *
from kivy.uix.screenmanager import ScreenManager, Screen, SlideTransition 
from kivy.properties import ObjectProperty, NumericProperty
from kivy.properties import StringProperty
from kivy.uix.image import Image
from kivy.uix.label import Label 
from kivy.graphics import *
from kivy.core.window import Window 
from kivy.uix.slider import Slider
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout   
from kivy.config import Config
from kivy.lang import Builder
from functools import partial
import time
i = 10
class Bar(Widget):
    pass

class Trial(Screen):
    rect1 = ObjectProperty(None)

#    Clock.schedule_interval(Trial().update, 1.0/60.0)

    def update(self):

        ser = serial.Serial('COM7', 9600, timeout=0)
        thing = [0,0]
        a = 1
        while a==1:
            Byte = ser.readline()
            Byte = Byte.decode('utf-8')
            Byte = Byte.strip()
            Byte_proc = Byte.split(',')
            if Byte_proc[0] != '':
                try:
                    if Byte_proc[1] != '':
                        Byte_proc[0] = int(Byte_proc[0])
                        Byte_proc[1] = int(Byte_proc[1])
                        TestTrial_SmallApp().first_rect = Byte_proc[0]
                        print(TestTrial_SmallApp().first_rect)
                        dummy_var = int(Byte_proc[0])
                        print(dummy_var)
                        a = 0
                        return dummy_var
                except:
                    pass
            time.sleep(.02)

class TestTrial_SmallApp(App):
    first_rect = NumericProperty(100)
    def build(self):

    #Builder.load_file('TestTrial.kv')
        Trial().add_widget(Bar())
        Clock.schedule_interval(lambda dt: Trial().update(), 1.0/60.0)
#       Trial().rect1.bind(pos = (200,200))
        Trial().update()
        return Trial()

TestTrial_SmallApp().run()

.kv文件

#:import utils kivy.utils
#:import Window kivy.core.window
#:import Widget kivy.uix.widget

<Trial>:
    id: "trial"
    rect1: bar_left

    canvas.before:
        Color:
            rgb: 1, 1, 1
        Rectangle:
            pos: self.pos
            size: self.size

        #Rectangle orange bars

    Bar:
        id: bar_left
        pos: 0.25*self.center_x, 0.02*self.height

<Bar>:
    canvas:
        Color:
            rgb: utils.get_color_from_hex('#F68C43')
        Rectangle:
            pos: 300, 300
            size: 300, app.first_rect

1 个答案:

答案 0 :(得分:0)

在下面的声明中

TestTrial_SmallApp().first_rect = Byte_proc[0]
print(TestTrial_SmallApp().first_rect)

每个TestTrial_SmallApp()都在创建TestTrial_SmallApp类的新实例。我认为这不是您想要的。创建一个分配给引用的实例,然后使用该引用来使用该实例,例如

app = TestTrial_SmallApp()
app.first_rect = ...
print(app.first_rect)