在 Kivy 中，我如何从另一个以 kv 语言显示的另一个屏幕获取变量

Question

我正在尝试从 kivy 文档修改乒乓球游戏。

我已经制作了一个“游戏结束”屏幕，应用程序在宣布获胜者后进入该屏幕，在那里我想要一个显示获胜者得分的标签，使用下面使用的方法我在标签中得到完全不同的输出,

有人可以解释一下我应该如何实现吗？谢谢！！

相关代码位于两者的底部，我只是将整个代码包括在内，以防问题出在其他地方。

import kivy
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.properties import NumericProperty, ReferenceListProperty, ObjectProperty
from kivy.vector import Vector
from kivy.uix.floatlayout import FloatLayout
from kivy.uix import label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.clock import Clock
from kivy.config import Config
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label





class WindowManager(ScreenManager):

    def On_Win(self):
        p1 =self.Game.player_1.score



class MenuWindow(Screen):
    pass 

class PongBall(Widget):
    velocity_y= NumericProperty(0)
    velocity_x= NumericProperty(0)

    velocity=ReferenceListProperty(velocity_x,velocity_y)

    def move(self):
        self.pos = Vector(self.velocity) +self.pos



class PongPad(Widget):

    score=NumericProperty(0)

    def Check_bounce(self,ball):
        if self.collide_widget(ball)   :
            vx,vy= ball.velocity
            bounced= Vector(-1* vx, vy )
            speedup= abs(((ball.velocity_x *0.1) -(ball.center_y - self.center_y)) *0.002) 
            vel = bounced *  (speedup +1.1)
            offset=(((ball.center_y - self.center_y)/2) - (ball.velocity_x /2)) *0.1
            if (ball.center_y - self.center_y) > 0:
                ball.velocity=vel.x,vel.y
                ball.velocity_y= 2
            else:
                ball.velocity= vel.x,vel.y
                ball.velocity_y= -2


class Game(Screen):



    ball = ObjectProperty(None)
    player_1 = ObjectProperty(None)
    player_2 = ObjectProperty(None)
    win1=NumericProperty(0)
    win2=NumericProperty(0)
    def on_enter(self, *args):
        self.serve_ball()
        Clock.schedule_interval(self.update, 1.0/60.0)

    def Winner(self):
        Winner=""
        if self.player_1.score==2:
            if self.manager.current != "WinGame":
                self.manager.current = "WinGame"
                Winner = "P1 with",str(self.player_1.score) 
        if self.player_2.score == 2:
            if self.manager.current !="WinGame":
                self.manager.current = "WinGame"
                Winner = "P2 with",str(self.player_2.score)

    def TEST(self):#TESTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT
        Winner=""
        if self.player_1.score>=2:
            Winner = "P1 with",str(self.player_1.score)
        print("1")
        print(Winner)
        return Winner
    def serve_ball(self,vel=(4,0)):
        print("234Served")
        self.ball.velocity= vel
        self.ball.center = self.center
        self.player_1.center_y=self.center_y
        self.player_2.center_y=self.center_y


    def Check_Top_Bottom(self):
        #Check bottom collion
        if self.ball.y <0:
            self.ball.velocity_y= abs(self.ball.velocity_y)

        #Check top colision
        if self.ball.y+50> self.height:
            self.ball.velocity_y = -abs(self.ball.velocity_y)

    def Check_if_score(self):#Score
        if self.ball.x >self.width:
            self.player_1.score +=1
            self.win1 +=1
            self.serve_ball()
        if self.ball.x+50 <0:
            self.player_2.score += 1
            self.win2 +=1
            self.serve_ball()

    def update(self,dt):
        self.ball.move()
        self.Check_Top_Bottom()
        self.Check_if_score()
        self.player_1.Check_bounce(self.ball)
        self.player_2.Check_bounce(self.ball)
        self.Winner()
        #print("from Update: ",self.Get_Score())


    def on_touch_move(self,touch):
        if touch.x > self.width/2:
            self.player_2.center_y = touch.y
        else:
            self.player_1.center_y= touch.y



class WinGameScreen(Screen):
    def Get_Win(self):
        screen_manager = self.manager
        game = screen_manager.get_screen('Game')
        a= game.TEST()
        return a


kv= Builder.load_file("myMenu.kv")


class myMenuApp(App):
    def build(self):
        return kv




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

这里是kv文件：

WindowManager:
    MenuWindow:
    Game:
    WinGameScreen:

<MenuWindow>:
    name: "Menu"
    FloatLayout:
        Button:
            size_hint: 0.2,0.05
            pos_hint: {"x":0.39,"y":0.75}
            text:"Play"
            on_release:
                app.root.current= "Game"
                root.manager.transition.direction= "left"
        Button:
            size_hint: 0.2,0.05
            pos_hint: {"x":0.39,"y":0.7}
            text:"Settings"
        Button:
            size_hint: 0.2,0.05
            pos_hint: {"x":0.39,"y":0.65}
            text:"High Score"
        Button:
            size_hint: 0.2,0.05
            pos_hint: {"x":0.39,"y":0.6}
            text:"Quit"

<PongBall>
    size_hint: None, None
    size: 50,50
    canvas:
        Ellipse:
            pos:self.pos
            size:self.size




<PongPad>
    size_hint: None, None
    size:25,150
    canvas:
        Rectangle:
            pos:self.pos
            size:self.size

<Game>:
    name:"Game"
    ball: Pong_ball
    player_1: Player1
    player_2: Player2


    canvas:
        Rectangle:
            pos:self.center_x -5,0
            size: 15,root.height

    PongPad:
        id: Player2
        pos:root.width-25,root.center_y-75

    PongPad:
        id: Player1
        pos:0,root.center_y-75

    PongBall:
        id: Pong_ball
        center: self.parent.center



        FloatLayout:

        Label:
            text:str(root.player_1.score)
            top:root.top -1
            x:root.width -100

        Label:
            text:"Player 2:"
            top: root.top-1
            x:root.width - 135

        Label:
            text: str(root.player_2.score)
            top: root.top -1
            x: root.x+25


        Label
            text: "Player 1:"
            top:root.top-1
            x:root.x -10

<WinGameScreen>:
    name:"WinGame"

    Label:
        id: Final_score
        text: str(root.Get_Win)
        y:0.2

Answer 1

在您的kv 中，一行：

    text: str(root.Get_Win)

在加载kv 时将Label 的文本设置为Get_Win() 方法的字符串版本。它没有运行Get_Win() 方法。您可以删除该行。

由于您在游戏结束时切换到WinGameScreen，因此您可以为WinGameScreen 定义一个on_enter() 方法，该方法将在输入Screen 时运行：

class WinGameScreen(Screen):
    def on_enter(self, *args):
        screen_manager = self.manager
        game = screen_manager.get_screen('Game')
        a= game.TEST()
        self.ids.Final_score.text = str(a)