kivyMD：如何使用工具栏操作项创建下拉菜单？

Question

我是 kivymd 的初学者。我试图创建一个像现实生活中的移动应用程序那样的事件。换句话说，当我按下 python kivymd 中的工具栏操作项时，我正在尝试类似下拉菜单。我的要求与下面给出的图像完全相同。

我只能简单地实现下拉菜单。这是我的简单代码，

from kivy.lang import Builder
from kivy.metrics import dp
from kivy.properties import StringProperty
from kivymd.uix.list import OneLineListItem
from kivymd.app import MDApp
from kivymd.uix.menu import MDDropdownMenu

KV = '''
MDScreen:
    MDDropDownItem:
        id: drop_item
        pos_hint: {'center_x': .5, 'center_y': .5}
        text: 'Select'
        on_release: app.menu.open()

'''

class Test(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.screen = Builder.load_string(KV)
        d_items = ['Snapshot','Settings','History','Logout','Exit']
        menu_items = [
            {
                "viewclass": "OneLineListItem",
                "text": i,
                "height": dp(40),
                "on_release": lambda x=i: self.set_item(x),
            } for i in d_items
        ]
        self.menu = MDDropdownMenu(
            caller=self.screen.ids.drop_item,
            items=menu_items,
            position="center",
            width_mult=2,
        )
        self.menu.bind()

    def set_item(self, text_item):
        self.screen.ids.drop_item.text=text_item
        self.menu.dismiss()


    def build(self):
        return self.screen


Test().run()

现在我想实现该事件，就像两个图像中显示的那样。如何在 kivymd 中实现这一点？

Answer 1

试试这个，在屏幕上很难正确定位菜单，你必须根据移动设备的分辨率来计算正确的位置：

from kivy.lang import Builder
from kivy.metrics import dp
from kivy.properties import StringProperty
from kivymd.uix.list import OneLineListItem
from kivymd.app import MDApp
from kivymd.uix.menu import MDDropdownMenu
from kivymd.uix.label import MDLabel
from kivy.core.window import Window

import os
if os.path.exists("_python_bundle/")==False:
    try:
        Window.size=(350,600)
    except:
        pass

from kivy.lang import Builder
from kivy.properties import StringProperty, NumericProperty
from kivy.uix.behaviors import ButtonBehavior
from kivy.uix.widget import Widget

from kivymd.uix.behaviors import RectangularRippleBehavior
from kivymd.uix.boxlayout import MDBoxLayout
from kivy.uix.boxlayout import BoxLayout
from kivymd.theming import ThemableBehavior

KV = '''
Screen:
    ScreenManager:
        Screen:
            name: "screen1"
            MDToolbar:
                pos_hint: {'top': 1}
                title: "App jbsidis"
                right_action_items: [["dots-vertical", lambda x:app.menu.open()]]
                left_action_items: [["menu", lambda x:app.menu.open()]]
    FloatLayout:
        MDDropDownItem_jbsidis:
            id: drop_item
            size: 1, 0
            pos_hint: {'center_x': .42, 'center_y': .72}
            #pos_hint: {'center_x': .320215, 'center_y': .68} #398 #complex location for menu by jbsidis, you must calculate this on a cellphone device

<MDDropDownItem_jbsidis>
    orientation: "vertical"
    adaptive_size: True
    spacing: "5dp"
    padding: "-20dp", "0dp", "0dp", 0
    
    FloatLayout:
        adaptive_size: True
        padding: dp(-10)
        spacing: "10dp"
        #pos_hint: {'center_x': .6}

        MDLabel:
            id: label_item
            size_hint: None, None
            #size: self.texture_size
            color: root.theme_cls.text_color
            font_size: root.font_size
<jbsidis_item>
    MDLabel:
        text: root.text
    


'''

class MDDropDownItem_jbsidis(ThemableBehavior, RectangularRippleBehavior, ButtonBehavior, MDBoxLayout):
    text = StringProperty()
    current_item = StringProperty()
    font_size = NumericProperty("18sp")
    def on_text(self, instance, value):
        self.ids.label_item.text = value

    def set_item(self, name_item):
        self.ids.label_item.text = name_item
        self.current_item = name_item

class jbsidis_item(MDBoxLayout):
    text = StringProperty()
    pass


class JBSIDIS(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.screen = Builder.load_string(KV)
        d_items = ['Snapshot','Settings','History','Logout','Exit']
        menu_items = [
            {
                "viewclass": "MDDropDownItem_jbsidis",
                "markup": True,
                "text": "[b]"+i,
                "height": dp(30),
                "divider": None,
                "on_release": lambda x=i: self.set_item(x),
            } for i in d_items
        ]
        self.menu = MDDropdownMenu(
            caller=self.screen.ids.drop_item,
            items=menu_items,
            position="center",
            width_mult=3.3,
            hor_growth="right",
            opening_time=2,
        )
##        self.menu = MDDropdownMenu(
##            caller=self.screen.ids.drop_item,
##            items=menu_items,
##            position="center",
##            width_mult=3.3,
##            hor_growth="right",
##            opening_time=2,
##            background_color=[.1,0,1,.5]
##        )
        #to change the bg color of the menu just  add remove the line "background_color=[.1,0,1,.5]"
        self.menu.bind()

    def set_item(self, text_item):
        self.screen.ids.drop_item.text=text_item
        self.menu.dismiss()


    def build(self):
        return self.screen


JBSIDIS().run()

图片：

Answer 2

近似解

from kivy.lang import Builder
from kivy.metrics import dp
from kivymd.app import MDApp
from kivymd.uix.menu import MDDropdownMenu
from kivy.core.window import Window

Window.size=(340,610)
KV = '''
MDScreen:

    MDToolbar:
        id:tool1
        title:'My Demo App'
        pos_hint:{'top':1}
        right_action_items : [["dots-vertical", lambda x: app.menu.open()]]

'''


class Test(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.screen = Builder.load_string(KV)
        items_d = ['Snapshot','Settings','History','Logout','Exit']
        menu_items = [
            {
                "text": f"{i}",
                "viewclass": "OneLineListItem",
                "height": dp(40),
                "on_release": lambda x=f"{i}": self.menu_callback(x),
            } for i in items_d
        ]
        self.menu = MDDropdownMenu(
            caller=self.screen.ids.tool1,
            items=menu_items,
            width_mult=2,
        )

    def menu_callback(self, text_item):
        print(text_item)
        self.menu.dismiss()

    def build(self):
        return self.screen


Test().run()