如何将kivy中的文本输入保存到变量中

Question

我是 kivy 的初学者，我正在尝试制作这个应用程序，下面的代码需要一些关于如何将人名保存到变量中的帮助，以便我可以在其他屏幕上使用它。 自定义屏幕类有我的保存名称按钮和文本输入，我想保存来自该屏幕的文本输入。当用户按下保存名称时，它会将屏幕更改为驾驶屏幕并希望在此屏幕中使用该名称 请耐心阅读，如果可以的话，请帮助我。 谢谢

from kivy.app import App
import cv2
import numpy as np
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.screenmanager import SlideTransition
from kivy.uix.textinput import TextInput
from kivy.properties import StringProperty

class CustomScreen(Screen):


    def softAlarm(self, *args):
        self.sound = SoundLoader.load('Soft-alarm-tone.mp3')
        self.sound.loop = True
        self.sound.play()



    def __init__(self, **kwargs):

        super(CustomScreen, self).__init__(**kwargs)

 
        layout = BoxLayout(orientation='vertical')


        layout.add_widget(Label(text='Driving Patner', font_size=50))


        navig = BoxLayout(size_hint_y=0.2)

        label1 = Label(text='Enter your name:', font_size = 30 , valign = 'bottom')

        navig.add_widget(label1)
      
        next = TextInput(font_size=30)

        name = next.text

        btn=Button(text='Save Name', font_size=30 , valign = 'bottom' ,halign='right')

        btn.bind(on_release=self.switch_next)
 
        navig.add_widget(next)
        navig.add_widget(btn)
        layout.add_widget(navig)


        self.add_widget(layout)


#Here we can write the code to start video analysis and all that
    def switch_next(self, *args):
        self.manager.transition = SlideTransition(direction="right")
        self.manager.current = self.manager.next()



class DrivingScreen(Screen):



    def __init__(self, **kwargs):

        super(DrivingScreen, self).__init__(**kwargs)




        layout = BoxLayout(orientation='vertical')


        layout.add_widget(Label(text='Safe Driving', font_size=50))


        navig = BoxLayout(size_hint_y=0.2)

        next = Button(text='Start Driving')

        next.bind(on_release=self.switch_next)

        navig.add_widget(next)
        layout.add_widget(navig)

        self.add_widget(layout)

#Here we can write to stop video analysis 
    def switch_next(self, *args):
        self.manager.transition = SlideTransition(direction="right")
        self.manager.current = self.manager.next()
        cap = cv2.VideoCapture(0)
        face = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') #reference: https://github.com/opencv/opencv/tree/master/data/haarcascades
        eyes = cv2.CascadeClassifier('haarcascade_eye.xml') #reference: https://github.com/opencv/opencv/blob/master/data/haarcascades/haarcascade_eye.xml
        while (True):

                ret, frame = cap.read()

                gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
                faces = face.detectMultiScale(gray, scaleFactor=1.5, minNeighbors=5)

                if len(faces) > 0:
                        print('Face Detected')
                else:
                        print('Face not Detected')
                #Clock.schedule_once(self.softAlarm, 3)
                #time.sleep(5) this freezes the whole program, best to find another way to implement
                #Event.wait(5)
                        cv2.rectangle(frame,(0,200), (640,300),(0,255,0),cv2.FILLED)
                        cv2.putText(frame, "User Distracted",(150,265),cv2.FONT_HERSHEY_COMPLEX_SMALL,2,(0,0,0),2 )
                #softAlarm()

                for (x, y, w, h) in faces:
                #getting coordinates of face
                #print(x,y,w,h)
                        roi = frame[y:y+h, x:x+w]

                #setting up bounding boxes for face
                        color = (0, 0, 255)                     #note that colors are in BGR and not RGB
                        color2 = (0, 255, 0 )
                        stroke = 3
                        width = x+w
                        height = y+h

                #drawing the bounding box with text
                        cv2.rectangle(frame, (x, y), (width, height), color, stroke )
                        cv2.putText(frame, "Face Detected", (x,y-5), cv2.FONT_HERSHEY_PLAIN, 1, color2, 2 )

                        roi_gray = gray[y:y+h, x:x+w]
                        roi_color = frame[y:y+h, x:x+w]
     
                        eye = eyes.detectMultiScale(roi_gray, scaleFactor=1.3, minNeighbors=2)
                        if len(eye) > 0:
                                print('Eyes detected')
                        else:
                                print('Eyes not detected')
                                cv2.rectangle(frame,(0,200), (640,300),(0,0,255),cv2.FILLED)
                                cv2.putText(frame, "Pay Attention!",(150,265),cv2.FONT_HERSHEY_COMPLEX_SMALL,2,(0,0,0),2 )
                        for (ex, ey, ew, eh) in eye:
                                cv2.rectangle(roi_color,(ex,ey), (ex+ew, ey+eh),color2,2)
                cv2.imshow('Video', frame)

                if cv2.waitKey(1) & 0xFF == ord('q'):
                        break
        cap.release()
        cv2.destroyAllWindows()

class DrivingSummary(Screen):



    def __init__(self, **kwargs):

        super(DrivingSummary, self).__init__(**kwargs)




        layout = BoxLayout(orientation='vertical')


        layout.add_widget(Label(text='Here is your driving summary', font_size=50))


        navig = BoxLayout(size_hint_y=0.2)

        next = Button(text='START DRIVING AGAIN')

        next.bind(on_release=self.switch_next)

        navig.add_widget(next)
        layout.add_widget(navig)

        self.add_widget(layout)


    def switch_next(self, *args):
        self.manager.transition = SlideTransition(direction="right")
        self.manager.current = self.manager.next()


class ScreenManagerApp(App):


    def build(self):

        root = ScreenManager()
        root.add_widget(CustomScreen(name='Screen1'))
        root.add_widget(DrivingScreen(name='Screen2'))
        root.add_widget(DrivingSummary(name='Screen3'))
        return root


# This is only a protection, so that if the file
# is imported it won't try to launch another App

if __name__ == '__main__':
    # And run the App with its method 'run'
    ScreenManagerApp().run()

Answer 1

您可以保存对 Screens 中小部件的引用。比如你的名字TextInput可以通过修改CustomScreen的__init__()方法来保存：

    ...

    self.next = TextInput(font_size=30)  # save reference to this TextInput

    name = self.next.text

    btn = Button(text='Save Name', font_size=30, valign='bottom', halign='right')

    btn.bind(on_release=self.switch_next)

    navig.add_widget(self.next)

    ...

而在DrivingScreen的__init__()方法中，可以创建一个Label来显示名字：

    ...

    self.driver_name = Label(font_size=25)

    layout.add_widget(self.driver_name)

    ...

那么这些引用就可以用在CustomScreen的switch_next()方法中了：

def switch_next(self, *args):
    self.manager.transition = SlideTransition(direction="right")
    self.manager.current = self.manager.next()
    self.manager.current_screen.driver_name.text = self.next.text