在Kivy for Python中按下按钮时更新label的文本

Question

这是我的代码：我想做一个游戏，当你按下一个按钮，主标签改变文本，但我已经到处找了一个星期，仍然不知道如何做。我看了基维的网站，但我不明白。正如你所见，我是基维的新手，经验不多

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout
from kivy.clock import Clock

energy = 100
hours = 4

class app1(App):
    def build(self):
        self.f = FloatLayout()

        #Labels
        self.energy_label = Label(text = "Energy = " + str(energy), size_hint=(.1, .15),pos_hint={'x':.05, 'y':.9})
        self.time_label = Label(text = "Hours = " + str(hours), size_hint=(.1, .15),pos_hint={'x':.9, 'y':.9})
        self.name_label = Label(text = "Game", size_hint=(.1, .15),pos_hint={'x':.45, 'y':.9})
        self.main_label = Label(text = "Default_text", size_hint=(1, .55),pos_hint={'x':0, 'y':.35})

        #Main Buttons
        self.inventory_button = Button(text = "Inventory", size_hint=(.3, .1),pos_hint={'x':.65, 'y':.2})
        self.help_button = Button(text = "Help", size_hint=(.3, .1),pos_hint={'x':.65, 'y':.1})
        self.craft_button = Button(text = "Craft", size_hint=(.3, .1),pos_hint={'x':.05, 'y':.1})
        self.food_button = Button(text = "Food", size_hint=(.3, .1),pos_hint={'x':.35, 'y':.2})
        self.go_button = Button(text = "Go", size_hint=(.3, .1),pos_hint={'x':.35, 'y':.1})
        self.walk_button = Button(text = "Walk", size_hint=(.3, .1),pos_hint={'x':.05, 'y':.2})

        def update(self, *args):
            self.main_widget.text = str(self.current_text)

        self.f.add_widget(self.energy_label)
        self.f.add_widget(self.main_label)
        self.f.add_widget(self.time_label)
        self.f.add_widget(self.inventory_button)
        self.f.add_widget(self.help_button)
        self.f.add_widget(self.craft_button)
        self.f.add_widget(self.food_button)
        self.f.add_widget(self.go_button)
        self.f.add_widget(self.walk_button)
        self.f.add_widget(self.name_label)
        self.current_text = "Default"
        Clock.schedule_interval(update, 1)
        return self.f


        def update_label(input):
            input = self.current_text

        help_button.bind(on_press = update_label("success!"))


if __name__=="__main__":
    app1().run()

如何更新代码，以便通过按“帮助”按钮，主标签更改其文本？

谢谢你的帮助。

Answer 1

另一种方法是，在Kivy中，Kivy语言属性右边的所有内容都是纯python。因此，您可以将kivy文件连接到python，方法是向函数传递一些标记，然后根据需要在python中执行任何操作。

在.kv文件中：

Button: 
   on_press: root.label_change('btn1')

在Python文件中：

Class MyButton(Button): 

    def label_change(self, event):
     self.event = event 

        if self.event == "btn1": 
           label.text = "something"

Answer 2

好吧！你的代码确实需要改进。（我理解，因为你没有经验。）

改进：1

如果在build（）上返回小部件，或者设置 self.root（不应该在构建函数中生成所有的gui）

def build(self):
    return Hello() #That's what is done here

改进：2

在释放/按两个键总是有用的。

self.help_button = Button(text = "Help", size_hint=(.3, .1),pos_hint={'x':.65, 'y':.1},on_press = self.update)

改进：3

当按下“帮助”按钮时，将调用“更新”功能来更改主标签的文本。

def update(self,event):
    self.main_label.text = "Changed to change"

这是完整的改进代码

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout
from kivy.clock import Clock

energy = 100
hours = 4

class Hello(FloatLayout):
    def __init__(self,**kwargs):
        super(Hello,self).__init__(**kwargs)

        self.energy_label = Label(text = "Energy = " + str(energy), size_hint=(.1, .15),pos_hint={'x':.05, 'y':.9})
        self.time_label = Label(text = "Hours = " + str(hours), size_hint=(.1, .15),pos_hint={'x':.9, 'y':.9})
        self.name_label = Label(text = "Game", size_hint=(.1, .15),pos_hint={'x':.45, 'y':.9})
        self.main_label = Label(text = "Default_text", size_hint=(1, .55),pos_hint={'x':0, 'y':.35})

    #Main Buttons
        self.inventory_button = Button(text = "Inventory", size_hint=(.3, .1),pos_hint={'x':.65, 'y':.2})
        self.help_button = Button(text = "Help", size_hint=(.3, .1),pos_hint={'x':.65, 'y':.1},on_press = self.update)
        self.craft_button = Button(text = "Craft", size_hint=(.3, .1),pos_hint={'x':.05, 'y':.1})
        self.food_button = Button(text = "Food", size_hint=(.3, .1),pos_hint={'x':.35, 'y':.2})
        self.go_button = Button(text = "Go", size_hint=(.3, .1),pos_hint={'x':.35, 'y':.1})
        self.walk_button = Button(text = "Walk", size_hint=(.3, .1),pos_hint={'x':.05, 'y':.2})

        self.add_widget(self.energy_label)
        self.add_widget(self.main_label)
        self.add_widget(self.time_label)
        self.add_widget(self.inventory_button)
        self.add_widget(self.help_button)
        self.add_widget(self.craft_button)
        self.add_widget(self.food_button)
        self.add_widget(self.go_button)
        self.add_widget(self.walk_button)
        self.add_widget(self.name_label)
        self.current_text = "Default"

    def update(self,event):
        self.main_label.text = "Changed to change"

class app1(App):
    def build(self):
        return Hello()
if __name__=="__main__":
     app1().run()

Answer 3

小脏片段！

import kivy
kivy.require('1.9.1')
from kivy.app import App
from kivy.lang import Builder
from kivy.clock import Clock
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
import random,string
Builder.load_string('''
<updlbl>:
    orientation: 'vertical'
    Label:
        id: updlbl
        text: 'Update Label'
    Button:
        text: 'Click me'
        on_press: root.upd('updated text')
 ''')

 class updlbl(BoxLayout):
     def __init__(self, **kwargs):
       super(updlbl,self).__init__(**kwargs)
       pass

     def upd(self,txt):
       self.ids.updlbl.text = txt




 class UpdateLabel(App):
     def build(self):
     self.title = "Update Label"
     return updlbl()

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