Kivy Screenmanager 问题 -

Question

我目前正在努力使用 Kivy 的屏幕管理器功能。虽然它在菜单中有效，但它不会显示角色。我在文档中没有找到任何有用的信息。

这很好用，所以类不是问题：

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.image import Image
from kivy.core.window import Window


class Character(Widget):
    pass


class Basic(Image):


    def __init__(self, **kwargs):
        super(Basic, self).__init__(**kwargs)
        self._keyboard = Window.request_keyboard(None, self)
        if not self._keyboard:
            return
        self._keyboard.bind(on_key_down=self.on_keyboard_down)
        print('Basic initialised')

    def on_keyboard_down(self, keyboard, keycode, text, modifiers):
        if keycode[1] == 'left':
            self.x -= 10
            print('pressed left')
        elif keycode[1] == 'right':
            self.x += 10
            print('pressed right')
        elif keycode[1] == 'up':
            self.y += 10
            print('pressed up')
        elif keycode[1] == 'down':
            self.y -= 10
            print('pressed down')
        else:
            return False
        return True


class HemeApp(App):

    def build(self):
        wimg = Basic(source='sprite.png')
        m = Character()
        m.add_widget(wimg)
        return m


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

但是当我想通过 ScreenManager 在我的 GameScreen 上显示它时，它只是一个黑屏。

这是代码：

from kivy.app import App
from kivy.lang import Builder
from kivy.clock import Clock
from kivy.config import Config
from kivy.vector import Vector
from kivy.uix.label import Label
from kivy.uix.popup import Popup
from kivy.uix.image import Image
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.core.window import Window
from kivy.animation import Animation
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.behaviors import ButtonBehavior
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.screenmanager import ScreenManager, Screen

Builder.load_file('heme.kv')

##############################################################################################################################


class HemeApp(App):

    title = 'geme'
    icon = 'custoicon.png'

    def build(self):

        sm = ScreenManager()
        sm.add_widget(MenuScreen(name='menu'))
        sm.add_widget(SettingsScreen(name='settings'))
        sm.add_widget(CharacterCreationScreen(name='creationscreen'))
        sm.add_widget(GameScreen(name='gameplay'))

        return sm

    def save(self, plrname):
        fob = open('stats.txt', 'w+')
        fob.write(plrname + "\n")
        fob.close()


class MenuScreen(Screen):
    pass

class SettingsScreen(Screen):
    pass

class CharacterCreationScreen(Screen):
    pass

class Character(Widget):
    pass

class GameScreen(Screen):
    def playy(self):
        print ('playy fired')
        wimg = Basic(source='sprite.png')
        m = Character()
        m.add_widget(wimg)
        return m

    def on_enter(self):
        print ("on_enter fired")
        self.playy()



class MyButton(ButtonBehavior, Image):
    def __init__(self, **kwargs):
        super(MyButton, self).__init__(**kwargs)
        self.source = 'button.png'

    def on_press(self):
        self.source = 'button_pressed.png'

    def on_release(self):
        self.source = 'button.png'



class Basic(Image):


    def __init__(self, **kwargs):
        super(Basic, self).__init__(**kwargs)
        self._keyboard = Window.request_keyboard(None, self)
        if not self._keyboard:
            return
        self._keyboard.bind(on_key_down=self.on_keyboard_down)
        print('Basic initialised')

    def on_keyboard_down(self, keyboard, keycode, text, modifiers):
        print ('on_keyboard_down active')
        if keycode[1] == 'left':
            self.x -= 10
        elif keycode[1] == 'right':
            self.x += 10
        else:
            return False
        return True




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

加上 Kivy 代码：

#; kivy 1.10.0
#:import Factory kivy.factory.Factory

<MenuScreen>:
    FloatLayout:
        canvas.before:
            Rectangle:
                pos: self.pos
                size: self.size
                source: 'bg.png'

        MyButton:
            pos: (330, 400)
            allow_stretch: True
            background_color: (0,1,0,1)
            size_hint: (.2,.2)
            text: 'Play'
            on_release:
                root.manager.transition.direction = 'right'
                root.manager.current = 'creationscreen'
        Label:
            pos: (330, 450)
            text: 'Play'
            color: (1,0,0)

        MyButton:
            pos: (330, 300)
            size_hint: (.2,.2)
            text: 'Goto settings'
            on_release:
                root.manager.transition.direction = 'right'
                root.manager.current = 'settings'
        MyButton:
            pos: (330, 200)
            background_color: (1,0,0,1)
            size_hint: (.2,.2)
            text: 'Quit'
            on_release: exit()

<SettingsScreen>:
    FloatLayout:
        MyButton:
            pos: (330, 400)
            size_hint: (.2,.2)
            text: 'My settings button'
        MyButton:
            pos: (330, 300)
            size_hint: (.2,.2)
            text: 'Back to menu'
            on_release:
                root.manager.transition.direction = 'left'
                root.manager.current = 'menu'

<CharacterCreationScreen>:
    name: name_input
    FloatLayout:
        MyButton:
            pos: (330, 400)
            name: name_input
            size_hint: (.2,.2)
            text: 'Start game'
            on_release:
                root.manager.transition.direction = 'right'
                root.manager.current = 'gameplay'

        MyButton:
            pos: (430, 300)
            text: 'Save'
            on_release: app.save(name_input.text)
            size_hint: (.2,.2)

        TextInput:
            pos: (230, 300)
            id: name_input
            font_size: 20
            multiline: False
            size_hint: (.2,.2)

        MyButton:
            pos: (330, 200)
            size_hint: (.2,.2)
            text: 'Back to menu'
            on_release:
                root.manager.transition.direction = 'left'
                root.manager.current = 'menu'

<GameScreen>:
    game: game
    Character:
        id: game
        pos: self.pos

Answer 1

问题

该字符未显示，因为没有给出添加该字符的位置。

解决方案

1. 将 return m 替换为 self.add_widget(m)

片段

class GameScreen(Screen):
    def playy(self):
        print('playy fired')
        wimg = Basic(source='sprite.png')
        m = Character()
        m.add_widget(wimg)
        self.add_widget(m)

输出