Kivy- 课外调用方法

Question

我的.kv 文件中有 2 个按钮和 2 个标签

<Controller>:
    lbl1: first_check
    lbl2: second_check

BoxLayout:
    orientation: 'horizontal'


    Button:
        on_press: root.start_program()
        text: 'Start Program'


    Button:
        on_press: root.stop_program()
        text: "Stop Program"


    Label:
        id: first_check
        text: 'No distance given'

    Label:
        id: second_check
        text: 'No distance given'

在.py 文件中，我有根小部件Controller 类和一些附加函数check_distance 和end_goal 在类之外

def check_distance(dt):
"""The if statements in this block of code will be run if r.dist <= 2700"""
c = Controller()
r.loop()
print(r.dist)
if r.dist <= 2700:
    c.show_dist()
    time.sleep(0.5)
    r.loop()
    if r.dist <= 2700:
        c.lbl2.text = "Below 2700"
        end_goal()

def end_goal():
"""Stops the check_distance function from being called every 2 seconds then 
runs the next bit of code"""
    Clock.unschedule(check_distance)
    beepPin.write(1)
    time.sleep(1)
    beepPin.write(0)
    time.sleep(1)
    beepPin.write(1)
    time.sleep(1)
    beepPin.write(0)    

class Controller(BoxLayout):
    def __init__(self, **kwargs):
        super(Controller, self).__init__(**kwargs)



def start_program(self):
    """Tells the check_distance function to run every 2 seconds"""
    Clock.schedule_interval(check_distance, 2)



def stop_program(self):
    """Will stop the check_distance function from running"""
    Clock.unschedule(check_distance)
    self.lbl2.text = str(r.dist)

def show_dist(self):
    self.lbl1.text = str(r.dist)

class BaseMotorApp(App):
    def build(self):
        return Controller()

BaseMotorApp().run()

当按下Start Program 按钮时，check_distance 函数每 2 秒调用一次。一旦满足if 条件，它将运行所有check_distance 代码。我知道这是因为end_goal 被成功调用。问题是c.show_dist() 没有做任何事情，我没有收到任何错误。我希望它在Controller 类中调用show_dist 函数。我什至试图一起消除show_dist 函数，只是在check_distance 函数中键入self.lbl1.text = str(r.dist)，但仍然没有。我猜我调用这个类方法的方式一定有问题。有人可以帮帮我吗？

Answer 1

避免在 Kivy 应用程序中使用 time.sleep

您遇到的问题是由于 time.sleep。您应该将 time.sleep 替换为 Kivy Clock.schedule_once，如下例所示。

def check_distance(dt):
    """The if statements in this block of code will be run if r.dist <= 2700"""
    c = Controller()
    r.loop()
    print(r.dist)
    if r.dist <= 2700:
        c.show_dist()
        Clock.schedule_once(check_distance_assign_label, 0.5)


def check_distance_assign_label(dt):
    r.loop()
    if r.dist <= 2700:
        c.lbl2.text = "Below 2700"
        end_goal()


def end_goal():
    """Stops the check_distance function from being called every 2 seconds then
    runs the next bit of code"""
    Clock.unschedule(check_distance)
    Clock.schedule_once(beepPinWrite(0), 1.0)
    Clock.schedule_once(beepPinWrite(1), 2.0)
    Clock.schedule_once(beepPinWrite(0), 3.0)


def beepPinWrite(index, dt):
    beepPin.write(index)