如何参考屏幕管理器的屏幕

时间:2021-06-24 09:16:15

标签: python kivy

我还是 kivy 的新手,我似乎无法在其他地方找到我的案例。我想从主应用程序类访问屏幕类中的方法:

class MainGUI(Screen):
    d_travelled = StringProperty()
    def update_distance(self,dt):
         self.d_travelled = dt

class SecondaryGUI(Screen):
    pass

class GUIManager(ScreenManager):
    pass

class WindowGUI(App):
    def __init__(self):
        super().__init__()
        self.odrive = myDrive.Motors()
        threading.Thread(target = self.RobotControl).start()

    def build(self):
        self.title = 'MyTitle'
        kv = all_imports.Builder.load_file('kv_styles/robot_3.kv')# which instantiate the GUIs
        return kv
    
    def RobotControl(self):
        while True:
            self.root.update_distance(self.odrive.encoder_cal()) <-----Error
            

我在 WindowGUI 中有我的机器人指令,需要与 kivy 并排运行。首先,我想在我的 MainGUI 上显示编码器读数。但是 self.root 中的 RobotControl 指的是 GUIManager。当然,这会引发错误。我如何在 MainGUI 中引用 RobotControl?是否可以将 def update_distance(self,dt) 放入 GUIManager 并让 MainGUI 显示编码器读数?如果是这样,如何?

我的 kv 文件:

#:kivy 2.0
#:import utils kivy.utils
GUIManager:
    MainGUI:
    SecondaryGUI:

<MainGUI>:
    name: "main"

    BoxLayout:
        orientation: "horizontal"
        size: root.width, root.height #covers entire window
        padding: 15
        GridLayout:
            cols: 1
            spacing: 10
            size_hint_x: 0.4
            # padding_right: 50
            BoxLayout:
                orientation:"horizontal"
                size_hint: 1,.4 

                Label:
                    text: "Drop Distance"
                    size_hint: .75,0.1
                
                Button:
                    id: zero_drop
                    text: "Zero"
                    size_hint: .25,.1
                    on_press:app.odrive.zero_encoder_read()
            BoxLayout:
                orientation: "horizontal"
                TextInput:
                    id: Encoder
                    multiline: False
                    readonly: True
                    text: root.d_travelled <-------I want to display it here
                    size_hint_x: 0.75

1 个答案:

答案 0 :(得分:0)

感谢 el3phanten 来自 kivy discord 频道。这就是我解决问题的方法:

from kivy.clock import mainthread

class MainGUI(Screen):
    # Do something

class SecondaryGUI(Screen):
    pass

class GUIManager(ScreenManager):
    pass

class WindowGUI(App):
    d_travelled = StringProperty()
    def __init__(self):
        super().__init__()
        self.odrive = myDrive.Motors()
        threading.Thread(target = self.RobotControl).start()

    def build(self):
        self.title = 'MyTitle'
        kv = all_imports.Builder.load_file('kv_styles/robot_3.kv')
        return kv
    
    def RobotControl(self):
        while True:
            val = self.odrive.encoder_cal()
            self.set_val(val)

    @mainthread 
    def set_val(self, val) :
    self.d_travelled = val

和kv:

    BoxLayout:
                orientation: "horizontal"
                TextInput:
                    id: Encoder
                    multiline: False
                    readonly: True
                    text: app.d_travelled 
                    size_hint_x: 0.75