如何在kivy的类中插入Python脚本？

Question

我有一个 python 文本，我想把它放在 kivy 的一个类中。然后我想将这个类用作一个函数并从另一个类中调用它。我应该如何定义类？括号class FaceGenerator()应该写什么？

class FaceGenerator():
    # open the camera and capture video
    cam = cv2.VideoCapture(0)
    face_detector = 
    cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
    # Asking the user for an ID and Name
    ID = raw_input('Please insert your ID number  ')
    Name= raw_input('Please insert your Name  ')
    sample_number = 0 # a counter that counts the number of pictures for 
    each person in the database

    # detecting the face and draw rectangle on it
    while (True):
        retval,image = cam.read() # reading image from cam
        print np.shape(image)
        gray_image = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY) # converting 
        image to gray image
        faces = face_detector.detectMultiScale(gray_image,1.3,5)
        ''' detectMultiScale, detects objects of different sizes in the 
        input image.
        the detected objects are returned as a list of rectangles
        '''
        for (x,y,w,h) in faces:
            cv2.rectangle(image, (x,y), (x+w, y+h), (255,0,0), 2)
            sample_number=sample_number+1
        # saving the captured face in the facebase folder
            cv2.imwrite('Trainer/User.'+ID+'.'+str(sample_number)+'.jpg', 
         gray_image[y:y+h,x:x+w])
    # this loop drawing a rectabgle on the face while the cam is open 
        cv2.imshow('frame',image)
        if cv2.waitKey(100) & 0xFF == ord('q'):
            break
        elif sample_number==20:
            break

    cam.release()
    cv2.destroyAllWindows()
    return Label(text = "Succesfully created trainning set")

Answer 1

如果您想创建一个类，请将 object 放在括号中 --> class FaceGenerator(object): 但是在您的情况下，根本不需要类，您正在寻找的是一个函数。如果我理解正确，您只想在该类上调用一个函数，因此您只能首先定义一个函数

这是我认为您想做的一种方式：

from kivy.app import App
from kivy.base import Builder
from kivy.properties import ObjectProperty
from kivy.uix.boxlayout import BoxLayout


def FaceGenerator():
    #do your stuff
    face = 'PalimPalim'
    return face

Builder.load_string("""
<rootwi>:
    label_to_be_changed: label_to_be_changed
    orientation: 'vertical'
    Button:
        text:'klick me'
        on_press: root.change_Label_text()
    Label:
        id: label_to_be_changed

""")
class rootwi(BoxLayout):
    label_to_be_changed = ObjectProperty()

    def change_Label_text(self):
        temp_str = FaceGenerator()
        self.label_to_be_changed.text = temp_str

class MyApp(App):
    def build(self):
        return rootwi()

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

更多信息

• kv 中的 root 在这种情况下指的是最左边的小部件rootwi
• 为作为小部件一部分的小部件定义 ObjectProperty 是 我最喜欢的更新属性的方式。当然还有其他方法。

Answer 2

@PalimPalim 我在上面担任过您的结构。我的代码现在是这样的 Python代码

import kivy
import cv2, os
import numpy as np
from PIL import Image

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.lang import Builder
from kivy.config import Config
Config.set('graphics', 'fullscreen', '0')
Config.set('graphics','show_cursor','1')

def FaceGenerator():
# open the camera and capture video
    cam = cv2.VideoCapture(0)
    face_detector = 
    cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
    ID = 0
    sample_number = 0 # a counter that counts the number of pictures for 
    each person in the database

    # detecting the face and draw rectangle on it
    while (True):
        retval,image = cam.read() # reading image from cam
        print np.shape(image)
        gray_image = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY) # converting 
        image to gray image
        faces = face_detector.detectMultiScale(gray_image,1.3,5)
        ''' detectMultiScale, detects objects of different sizes in the 
        input image.
        the detected objects are returned as a list of rectangles
        '''
        for (x,y,w,h) in faces:
            cv2.rectangle(image, (x,y), (x+w, y+h), (255,0,0), 2)
            sample_number=sample_number+1
        # saving the captured face in the facebase folder

            cv2.imwrite('Trainer/User.'+str(ID)+'.'+str(sample_number)+'.jpg',
            gray_image[y:y+h,x:x+w])
    # this loop drawing a rectabgle on the face while the cam is open 
        cv2.imshow('frame',image)
        if cv2.waitKey(100) & 0xFF == ord('q'):
            break
        elif sample_number==20:
            break

    cam.release()
    cv2.destroyAllWindows()
    output = "Succesfully created trainning set"
    return output

class ScreenOne(Screen):
    pass

class ScreenTwo(Screen):
    pass

class ScreenThree(Screen):
        pass


class ScreenManagement(ScreenManager):
    pass


sm = Builder.load_file("facerecognition.kv")

class FaceRecognitionApp(App):
    def build(self):
        return sm

if __name__=="__main__":
    FaceRecognitionApp().run()

.KV 文件是：

ScreenManagement:
    id: screen_management
    ScreenOne:
    ScreenTwo:
    ScreenThree:



<ScreenOne>:
    name: "screen1"
    id: screen_one

    FloatLayout:
        canvas.before:
            Rectangle:
                source: "image1.jpg"
                pos:self.pos
                size:self.size

        Label:
            text:"Hello\n Welcome to my App\n"
            font_size:40 
            color: 0,0,0,1
        Button:
            text: 'Next'
            font_size: 32 # font size
            size_hint: .2,.1
            pos_hint:{'right':1, 'y':0}
            on_release: app.root.current="screen2"

<ScreenTwo>:
    name: "screen2"
    id: screen_two

    FloatLayout:
        canvas:

            Rectangle:
                source: "image1.jpg"
                pos:self.pos
                size:self.size

        Label:
            text:"Please insert your Name\n Please insert your Password\n"
            font_size:40 
            color: 0,0,0,1
        Button:
            text: 'Next'
            font_size: 32 # font size
            size_hint: .2,.1
            pos_hint:{'right':1, 'y':0}
            on_release: app.root.current="screen3"

<ScreenThree>:
    name: "screen3"
    id: screen_three


    FloatLayout:
        canvas:

            Rectangle:
                source: "image1.jpg"
                pos:self.pos
                size:self.size


        Button:
            text: 'Next'
            font_size: 32 # font size
            size_hint: .2,.1
            pos_hint:{'right':1, 'y':0}
            on_release: app.root.current="screen1"

        BoxLayout:
            orientation: 'horizontal'
            FaceGenerator()