更改Kivy小部件文本

Question

我正在尝试使用Kivy创建一个Pong游戏。 但是，当我尝试在某人获得10分后结束游戏时遇到了问题。 一切工作正常，除了我想使用标签显示“游戏结束”文本。 我创建了一个标签，当前文本设置为空字符串，但是在有人获得足够的分数后，它应该会更改。

我浏览了kivy文档并搜索了stackoverflow，但没有找到答案（或者至少没有一个我了解的答案）。

如果有人能指出正确的方向，我将不胜感激。

这是我的代码：

.py文件：

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.properties import NumericProperty, ReferenceListProperty,\
ObjectProperty
from kivy.vector import Vector
from kivy.clock import Clock


count1 = 0
count2 = 0



class PongPaddle(Widget):
    score = NumericProperty(0)

    def bounce_ball(self, ball):
        if self.collide_widget(ball):
            vx, vy = ball.velocity
            offset = (ball.center_y - self.center_y) / (self.height / 2)
            bounced = Vector(-1 * vx, vy)
            vel = bounced * 1.1
            ball.velocity = vel.x, vel.y + offset


class PongBall(Widget):
    velocity_x = NumericProperty(0)
    velocity_y = NumericProperty(0)
    velocity = ReferenceListProperty(velocity_x, velocity_y)

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


class PongGame(Widget):
    ball = ObjectProperty(None)
    player1 = ObjectProperty(None)
    player2 = ObjectProperty(None)


    def serve_ball(self, vel=(4, 0)):
        self.ball.center = self.center
        self.ball.velocity = vel

    def update(self, dt):
        global count1
        global count2

        self.ball.move()

        #bounce of paddles
        self.player1.bounce_ball(self.ball)
        self.player2.bounce_ball(self.ball)

        #bounce ball off bottom or top
        if (self.ball.y < self.y) or (self.ball.top > self.top):
            self.ball.velocity_y *= -1

        #went of to a side to score point?
        if self.ball.x < self.x:
            self.player1.score += 1
            count2 = count2 + 1
            self.serve_ball(vel=(4, 0))
        if self.ball.x > self.width:
            self.player2.score += 1
            self.serve_ball(vel=(-4, 0))

        if count1 or count2 >= 10:
            #
            #
            #
            #I don't know what needs to be placed here to change the third label's text


    def on_touch_move(self, touch):
        if touch.x < self.width / 3:
            self.player1.center_y = touch.y
        if touch.x > self.width - self.width / 3:
            self.player2.center_y = touch.y

class PongApp(App):
    def build(self):
        game = PongGame()
        game.serve_ball()
        Clock.schedule_interval(game.update, 1.0 / 60.0)
        return game



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

.kv文件

#:kivy 1.0.9

<PongBall>:
    size: 50, 50
    canvas:
        Ellipse:
            pos: self.pos
            size: self.size

<PongPaddle>:
    size: 25, 200
    canvas:
        Rectangle:
            pos: self.pos
            size: self.size


<PongGame>:
    ball: pong_ball
    player1: player_left
    player2: player_right

    canvas:
        Rectangle:
            pos: self.center_x - 5, 0
            size: 10, self.height

    Label:
        font_size: 70
        center_x: root.width / 4
        top: root.top - 50
        text: str(root.player2.score)

    Label:
        font_size: 70
        center_x: root.width * 3/4
        top: root.top - 50
        text: str(root.player1.score)

    PongBall:
        id: pong_ball
        center: self.parent.center

    PongPaddle:
        id: player_left
        x: root.x
        center_y: root.center_y

    PongPaddle:
        id: player_right
        x: root.width-self.width
        center_y: root.center_y

    Label:
        id: game_over_label
        text: " "
        font_size: 100
        center_x: root.width / 2
        center_y: root.height / 2

Answer 1

您将使用与更改得分时更改得分标签相同的方法来更改游戏结束标签。

如果添加ObjectProperty到PongGame在main.py：

end_label = ObjectProperty()

而在在你千伏文件PongGame ，写：

end_label: game_over_label  # linking them up

你可以添加一个功能PongGame在main.py类：

def check_score(self):
    scores = [self.player1.score,
              self.player2.score]
    for s in scores:
        if s == 10:
            self.end_label = "Game Over"
            return

然后在update功能中，您可以在分数增加时随时调用此功能，例如：

 self.player1.score += 1
 self.check_score()

和self.player2.score

Answer 2

在树中查找ID的一种方法是在小部件的根目录中放置一个“重定向器”

在.kv中，在PongGame下：

        gameoverlabel: game_over_label

在.py中的“如果count1或count2> = 10：”下添加

        self.gameoverlabel.text = "win"

希望这会有所帮助