Python 当kivy上发生事件时，如何增加计数器

我想生成一个计数，如果某个事件发生而我没有得到它，它会将计数器加1。其思想是，当将其中一个正确的图像（Dropable_zone_Object:[to_box，]）拖放到正确的位置时，计数器应添加+1。目前，该应用程序工作正常，但在打印计数器时，其值始终为1。我应该换什么

Arrastar.kv

#:kivy 1.9.0

<Relaciona3x2>:
    canvas.before:
        Rectangle:
            pos: self.pos
            size: self.size
            source: 'data/img/fondobosque.jpg'
    BoxLayout:
        orientation: 'vertical'
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iglu.png'
                bound_zone_objects: [from_box, to_box ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/indio.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_m/moto.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
        
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/una.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iman_1.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/urraca.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
            
        Image:
            id: to_box
            source: "data/img/caldero.png"
            
<Relaciona4x2>:
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False
            
<Relaciona5x2>:
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False

#:kivy 1.9.0
#:import FadeTransition kivy.uix.screenmanager.FadeTransition

<RelScreenManager>:
    transition: FadeTransition()
    Relaciona3x2:
    Relaciona4x2:
    Relaciona5x2:

<Relaciona3x2>:
    name: 'Rel3x2'
    id: Rel3x2
    canvas.before:
        Rectangle:
            pos: self.pos
            size: self.size
            source: 'data/img/fondobosque.jpg'
    BoxLayout:
        orientation: 'vertical'
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iglu.png'
                bound_zone_objects: [from_box, to_box ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/indio.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_m/moto.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
        
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/una.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iman_1.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/urraca.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
            
        Image:
            id: to_box
            source: "data/img/caldero.png"
            
<Relaciona4x2>:
    name: 'Rel4x2'
    id: Rel4x2
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False
            
<Relaciona5x2>:
    name: 'Rel5x2'
    id: Rel5x2
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False

---

在每次调用

greet（）

时，都会创建一个新的

Contador

实例。您可能应该只创建一个

Contador

实例，如下所示：

class ArrastraApp(App):
    def build(self):
        #Window.fullscreen = 'auto'
        self.cuenta = Contador()
        return Relaciona3x2()
    
    def greet(self):
        # cuenta = Contador()
        print('Draggin done!')
        if DragableButton.droppable_zone_objects is True:
            print(self.cuenta.next())

---

谢谢John，计数器已经做了正确的求和，但是现在当我尝试在计数器达到3时转到下一个屏幕时，它什么也不做

class ArrastraApp(App):
    def build(self):
        #Window.fullscreen = 'auto'
        self.cuenta = Contador()
        return Relaciona3x2()
        if self.cuenta == 3:
            return Relaciona4x2()
        
    
    def greet(self):
        #cuenta = Contador()
        print('Draggin done!')
        print(self.cuenta.next())

---

我还是无法进入下一个屏幕，约翰。我已经在ScreenManager中设置了计数器和If，但是我仍然无法从一个页面转到另一个页面，关于ScreenManager的操作有些我不知道

Arrastar.kv

#:kivy 1.9.0

<Relaciona3x2>:
    canvas.before:
        Rectangle:
            pos: self.pos
            size: self.size
            source: 'data/img/fondobosque.jpg'
    BoxLayout:
        orientation: 'vertical'
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iglu.png'
                bound_zone_objects: [from_box, to_box ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/indio.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_m/moto.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
        
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/una.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iman_1.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/urraca.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
            
        Image:
            id: to_box
            source: "data/img/caldero.png"
            
<Relaciona4x2>:
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False
            
<Relaciona5x2>:
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False

#:kivy 1.9.0
#:import FadeTransition kivy.uix.screenmanager.FadeTransition

<RelScreenManager>:
    transition: FadeTransition()
    Relaciona3x2:
    Relaciona4x2:
    Relaciona5x2:

<Relaciona3x2>:
    name: 'Rel3x2'
    id: Rel3x2
    canvas.before:
        Rectangle:
            pos: self.pos
            size: self.size
            source: 'data/img/fondobosque.jpg'
    BoxLayout:
        orientation: 'vertical'
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iglu.png'
                bound_zone_objects: [from_box, to_box ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/indio.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
                
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_m/moto.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
        
        BoxLayout:
            id: from_box
            
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/una.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_i/iman_1.png'
                bound_zone_objects: [from_box, to_box, ]
                droppable_zone_objects: [to_box, ]
                drop_func: app.greet
                
            Widget:
            
            DragableButton:
                canvas:
                    Rectangle:
                        pos: self.pos
                        size: self.size
                        source: 'data/img/letra_u/urraca.png'
                bound_zone_objects: [from_box, to_box, ]
                #droppable_zone_objects: [to_box, ]
                drop_func: app.greet

            Widget:
            
        Image:
            id: to_box
            source: "data/img/caldero.png"
            
<Relaciona4x2>:
    name: 'Rel4x2'
    id: Rel4x2
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False
            
<Relaciona5x2>:
    name: 'Rel5x2'
    id: Rel5x2
    AnchorLayout:
        Image:
            source: "data/img/fondobosque.jpg"
            allow_stretch: True
            keep_ratio: False

---

self.cuenta

永远不会等于3，因为

self.cuenta

不是数字，而是

Contador

类的实例。也许你应该将self.cuenta.numero与3进行比较。你说的没错，但现在的问题是我不知道如何调用下一个屏幕。我试着这样做：

if self.cuenta.numero==3:return Ralaciona4x2（）

它什么也不做，但是如果在

if

中我放了一个

print（self.cuenta.numero）

它会打印我帐户的结果，用它，

If

做得很好，但是对下一个屏幕的调用没有完成。只是在您将

If

语句放在哪里时才实现。在任何方法中，

返回后出现的任何代码都将永远不会执行。所以你的比较永远不会被执行。另外，当
run（）
方法启动
App
的
build（）
方法时，只调用一次。由于您使用的是
屏幕
，您可能应该使用
屏幕管理器
并根据您的比较切换
屏幕
。