单击kivy中的按钮后如何创建对象？

Question

我有一个想要在按下按钮时创建的“条纹”对象。我所拥有的是多个TextInputs和一个按钮。我希望按钮能够获取所有输入并将其存储在“ Streak”对象中。我将如何去做呢？这是.kv代码：

<ScreenOne>:
    name: "one"
    AnchorLayout:
        anchor_x: 'left'
        anchor_y: 'top'
        Button:
            on_release: app.root.current = "main"
            text: "Back"
            size: 50, 25
            size_hint: None, None
            font_size: 18
    GridLayout:
        cols:1
        rows:6
        Label:
            text: "Action"
            font_size: 18
            size: 600, 50
            size_hint: None, None
        TextInput:
            id: action_entry
            multiline: False
            size: 600, 28
            size_hint: None, None
        Label:
            text: "Streak #"
            size: 600, 50
            size_hint: None, None
        TextInput:
            id: streak_entry
            multiline: False
            size_hint: None, None
            size: 600, 28
        Label:
            size: 600, 50
            size_hint: None, None
            text: "Due every"

        GridLayout:
            cols:3
            rows:2
            Label:
                text: "Day(s)"
                size_hint: None, None
                font_size: 18
            Label:
                text: "Hour(s)"
                size_hint: None, None
                font_size: 18
            Label:
                text: "Minute(s)"
                size_hint: None, None
                font_size: 18
            TextInput:
                id: day_entry
                multiline: False
                size_hint: None, None
                size: 200, 28
            TextInput:
                id: hour_entry
                multiline: False
                size_hint: None, None
                size: 200, 28
            TextInput:
                id: minute_entry
                multiline: False
                size_hint: None, None
                size: 200, 28
    AnchorLayout:
        anchor_x: "right"
        anchor_y: "bottom"
        Button:
            text: "Add"
            size: 50, 25
            size_hint: None, None
            font_size: 18
            on_press: Streak.create(instance)

这是.py代码：

class Streak():
    def __init__(self, action, action_num, day, hour, minute):
        self.action = action
        self.action_num = action_num
        self.day = day
        self.hour = hour
        self.minute = minute

class MainScreen(Screen):
    pass

class ScreenOne(Screen):
    pass

class ScreenManagement(ScreenManager):
    pass

presentation = Builder.load_file("StreakStar.kv")

class MainApp(App):
    def build(self): # build() returns an instance
        return presentation

    def create(self, instance):
        streak = Streak(action_entry.text, streak_entry.text, day_entry.text,
                        hour_entry.text, minute_entry.text)


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

当我按下按钮时，我收到一个NameError：名称'Streak'未定义

Answer 1

所有ID已存储在ids库中-假设您想将此变量用作字符串，则可以串联所需的ID。

出现错误的原因是因为函数中先前未定义streak。

def create(self):
    streak = ""
    streak = self.ids.action_entry.text +", "+
             self.ids.streak_entry.text +", "+
             self.ids.day_entry.text....

将为您提供这些ids

的字符串

Answer 2

根本原因

当按下Add按钮时，它尝试调用Streak.create(instance)，但是没有名称为Streak的实例化对象，因此，它引发了以下错误：

  

NameError：名称'Streak'未定义

解决方案

kv文件

• 将Streak.create(instance)替换为app.create()

摘要

    Button:
        text: "Add"
        size: 50, 25
        size_hint: None, None
        font_size: 18
        on_press: app.create()

py文件

• 重写方法create()如下：

摘要

def create(self):
    obj = self.root.get_screen('one')
    self.streak = Streak(obj.ids.action_entry.text, obj.ids.streak_entry.text, obj.ids.day_entry.text, 
                         obj.ids.hour_entry.text, obj.ids.minute_entry.text)