问题
I am trying to display the speedometer in my MainWindow screen. Right now when i run the code, the speedometer works but it is not displayed on the MainWindow screen which i want rather it is just appearing on a normal screen. It is possible to combine class Gauge(Widget): and class MainWindow(Screen): together so that the speedometer will actually be displayed on the MainWindow?
.py file
import kivy
kivy.require('1.6.0')
from kivy.app import App
from kivy.clock import Clock
from kivy.properties import NumericProperty
from kivy.properties import StringProperty
from kivy.properties import BoundedNumericProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.widget import Widget
from kivy.uix.scatter import Scatter
from kivy.uix.image import Image
from kivy.uix.label import Label
from kivy.uix.progressbar import ProgressBar
from os.path import join, dirname, abspath
from kivy.uix.screenmanager import Screen, ScreenManager
class WindowManager(ScreenManager):
pass
class MainWindow(Screen):
pass
class Gauge(Widget):
unit = NumericProperty(1.8)
value = BoundedNumericProperty(0, min=0, max=100, errorvalue=0)
path = dirname(abspath(__file__))
file_gauge = StringProperty(join(path, "cadran.png"))
file_needle = StringProperty(join(path, "needle.png"))
size_gauge = BoundedNumericProperty(128, min=128, max=256, errorvalue=128)
size_text = NumericProperty(10)
def __init__(self, **kwargs):
super(Gauge, self).__init__(**kwargs)
self._gauge = Scatter(
size=(1350,600),
do_rotation=False,
do_scale=False,
do_translation=False
)
_img_gauge = Image(
source=self.file_gauge,
size=(1350,600)
)
self._needle = Scatter(
size=(self.size_gauge, self.size_gauge),
do_rotation=False,
do_scale=False,
do_translation=False
)
_img_needle = Image(
source=self.file_needle,
size=(self.size_gauge, self.size_gauge)
)
self._glab = Label(font_size=self.size_text, markup=True)
self._progress = ProgressBar(max=100, height=20, value=self.value , size=(500,400))
self._gauge.add_widget(_img_gauge)
self._needle.add_widget(_img_needle)
self.add_widget(self._gauge)
self.add_widget(self._needle)
self.add_widget(self._glab)
self.add_widget(self._progress)
self.bind(pos=self._update)
self.bind(size=self._update)
self.bind(value=self._turn)
def _update(self, *args):
'''
Update gauge and needle positions after sizing or positioning.
'''
self._gauge.pos = self.pos
self._needle.pos = (self.x, self.y)
self._needle.center = self._gauge.center
self._glab.center_x = self._gauge.center_x
self._glab.center_y = self._gauge.center_y + (self.size_gauge / 4)
self._progress.x = self._gauge.x + (self.size_gauge/0.468 )
self._progress.y = self._gauge.y + (self.size_gauge/4 )
self._progress.width = self.size_gauge
def _turn(self, *args):
'''
Turn needle, 1 degree = 1 unit, 0 degree point start on 50 value.
'''
self._needle.center_x = self._gauge.center_x
self._needle.center_y = self._gauge.center_y
self._needle.rotation = (50 * self.unit) - (self.value * self.unit)
self._glab.text = "[b]{0:.0f}[/b]".format(self.value)
self._progress.value = self.value
class GaugeApp(App):
increasing = NumericProperty(1)
begin = NumericProperty(50)
step = NumericProperty(1)
def build(self):
box = BoxLayout(orientation='horizontal', padding=5)
self.gauge = Gauge(value=50, size_gauge=256, size_text=25)
box.add_widget(self.gauge)
Clock.schedule_interval(lambda *t: self.gauge_increment(), 0.05)
return box
def gauge_increment(self):
begin = self.begin
begin += self.step * self.increasing
if begin > 0 and begin < 100:
self.gauge.value = begin
else:
self.increasing *= -1
self.begin = begin
if __name__ == '__main__':
GaugeApp().run()
回答1:
You need to create an instance of ScreenManager and an instance of Screen. Next you add_widget the Screen to ScreenManager and to the Screen you add box
sm = ScreenManager()
s1 = Screen()
s1.add_widget(box)
sm.add_widget(s1)
This is the complete code which uses your new classes
from kivy.app import App
from kivy.clock import Clock
from kivy.properties import NumericProperty
from kivy.properties import StringProperty
from kivy.properties import BoundedNumericProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.widget import Widget
from kivy.uix.scatter import Scatter
from kivy.uix.image import Image
from kivy.uix.label import Label
from kivy.uix.progressbar import ProgressBar
from os.path import join, dirname, abspath
from kivy.uix.screenmanager import Screen, ScreenManager
class WindowManager(ScreenManager):
pass
class MainWindow(Screen):
pass
class Gauge(Widget):
unit = NumericProperty(1.8)
value = BoundedNumericProperty(0, min=0, max=100, errorvalue=0)
path = dirname(abspath(__file__))
file_gauge = StringProperty(join(path, "cadran.png"))
file_needle = StringProperty(join(path, "needle.png"))
size_gauge = BoundedNumericProperty(128, min=128, max=256, errorvalue=128)
size_text = NumericProperty(10)
def __init__(self, **kwargs):
super(Gauge, self).__init__(**kwargs)
self._gauge = Scatter(
size=(1350,600),
do_rotation=False,
do_scale=False,
do_translation=False
)
_img_gauge = Image(
source=self.file_gauge,
size=(1350,600)
)
self._needle = Scatter(
size=(self.size_gauge, self.size_gauge),
do_rotation=False,
do_scale=False,
do_translation=False
)
_img_needle = Image(
source=self.file_needle,
size=(self.size_gauge, self.size_gauge)
)
self._glab = Label(font_size=self.size_text, markup=True)
self._progress = ProgressBar(max=100, height=20, value=self.value , size=(500,400))
self._gauge.add_widget(_img_gauge)
self._needle.add_widget(_img_needle)
self.add_widget(self._gauge)
self.add_widget(self._needle)
self.add_widget(self._glab)
self.add_widget(self._progress)
self.bind(pos=self._update)
self.bind(size=self._update)
self.bind(value=self._turn)
def _update(self, *args):
'''
Update gauge and needle positions after sizing or positioning.
'''
self._gauge.pos = self.pos
self._needle.pos = (self.x, self.y)
self._needle.center = self._gauge.center
self._glab.center_x = self._gauge.center_x
self._glab.center_y = self._gauge.center_y + (self.size_gauge / 4)
self._progress.x = self._gauge.x + (self.size_gauge/0.468 )
self._progress.y = self._gauge.y + (self.size_gauge/4 )
self._progress.width = self.size_gauge
def _turn(self, *args):
'''
Turn needle, 1 degree = 1 unit, 0 degree point start on 50 value.
'''
self._needle.center_x = self._gauge.center_x
self._needle.center_y = self._gauge.center_y
self._needle.rotation = (50 * self.unit) - (self.value * self.unit)
self._glab.text = "[b]{0:.0f}[/b]".format(self.value)
self._progress.value = self.value
class GaugeApp(App):
increasing = NumericProperty(1)
begin = NumericProperty(50)
step = NumericProperty(1)
def build(self):
box = BoxLayout(orientation='horizontal', padding=5)
self.gauge = Gauge(value=50, size_gauge=256, size_text=25)
box.add_widget(self.gauge)
Clock.schedule_interval(lambda *t: self.gauge_increment(), 0.05)
sm = WindowManager()
s1 = MainWindow()
s1.add_widget(box)
sm.add_widget(s1)
return sm
def gauge_increment(self):
begin = self.begin
begin += self.step * self.increasing
if begin > 0 and begin < 100:
self.gauge.value = begin
else:
self.increasing *= -1
self.begin = begin
if __name__ == '__main__':
GaugeApp().run()
来源：https://stackoverflow.com/questions/59067674/cant-display-speedometer-on-mainwindow-kivy