我正在制作一个带有多个屏幕的程序，每个屏幕都有自己的大小，因此每次更换屏幕时都必须重新调整应用程序的大小。
问题在于，当我改变窗户的大小时，Kivy只会增加或减少右侧和底侧的长度，而不是四边，因此屏幕总是得到“未经过调整的”＃34;改变尺寸后。
我试着用线条做一个例子：
-------------------------------- --------------------------------
| Monitor | | |
| -------- | | -------------- |
| | My | | | | | |
| | App | | > | | | |
| -------- | | | | |
| | | |______________| |
-------------------------------- --------------------------------
就像你可以看到程序只改变右侧和下侧的长度。
如何让屏幕再次居中或更好地改变四边的尺寸，而不仅仅是两个？
这是我的代码示例，但我不知道该怎么做：
.py示例：from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.core.window import Window
class Screen_Manager(ScreenManager):
pass
class Main(Screen):
def __init__(self, **kwargs):
super(Main, self).__init__(**kwargs)
def on_pre_enter(self):
Window.size = (900, 500)
class Login(Screen):
def __init__(self, **kwargs):
super(Login, self).__init__(**kwargs)
def on_pre_enter(self):
Window.size = (400, 300)
class MyApp(App):
def build(self):
return Screen_Manager()
MyApp().run()
my.kv示例（my，以便与MyApp一起使用）：<Screen_Manager>:
id: screen_manager
Main:
Login:
<Login>:
name: 'login'
Button:
text: 'Go to Main'
on_press: root.manager.current = 'main'
<Main>:
name: 'main'
Button:
text: 'Go to Login'
on_press: root.manager.current = 'login'
我找到了一条路，但我不喜欢它：
def on_pre_enter(self):
# New size
size = (NEW_X, NEW_Y)
# Get the actual pos and knowing the old size calculate the new one
top = Window.top * Window.size[1] / size[1]
left = Window.left * Window.size[0] / size[0]
# Change the size
Window.size = size
# Fixing pos
Window.top = top
Window.left = left
答案 0 :(得分：2)
我找不到任何暗示kivy能够提供主机设备的屏幕尺寸，所以我希望如果有，有人会告诉我们。与此同时，我从另一个论坛借用了一些设置代码。我只是在我的macbook上测试它，它似乎工作，获得屏幕大小。我不知道在Windows，Linux或多个监视器上会发生什么。但这是新代码：
import sys
"""
returns Monitor size x and y in pixels for desktop platforms, or None for
mobile platforms
Found at:
https://groups.google.com/forum/#!topic/kivy-users/uZYrghb87g0
"""
if sys.platform == 'linux2':
import subprocess
output = subprocess.Popen(
'xrandr | grep "\*" | cut -d" " -f4',
shell=True,
stdout=subprocess.PIPE).communicate()[0]
screenx = int(output.replace('\n', '').split('x')[0])
screeny = int(output.replace('\n', '').split('x')[1])
elif sys.platform == 'win32':
from win32api import GetSystemMetrics
screenx = GetSystemMetrics(0)
screeny = GetSystemMetrics(1)
elif sys.platform == 'darwin':
from AppKit import NSScreen
frame_size = NSScreen.mainScreen().frame().size
screenx = frame_size.width
screeny = frame_size.height
else:
# For mobile devices, use full screen
screenx,screeny = 800,600 # return something
#print "screenx,screeny = ",repr((screenx,screeny))
from kivy.config import Config # config should appear before any other kivy stuff
Config.set('graphics','position','custom')
from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.core.window import Window
class Screen_Manager(ScreenManager):
pass
def center_window(sizex,sizey):
Window.size = (sizex, sizey)
Window.left = (screenx - sizex)/2
Window.top = (screeny - sizey)/2
class Main(Screen):
def __init__(self, **kwargs):
super(Main, self).__init__(**kwargs)
def on_pre_enter(self):
center_window(900,500)
class Login(Screen):
def __init__(self, **kwargs):
super(Login, self).__init__(**kwargs)
def on_pre_enter(self):
center_window(400, 300)
class MultiScreenApp(App):
def build(self):
return Screen_Manager()
MultiScreenApp().run()
答案 1 :(得分：0)
我这样做的方法是保存初始Window.center值，并在调整大小事件之后将Window.left和Window.top值的变化减去。即：
initial_center = None
def build(self):
self.initial_center = Window.center
有关窗口更改事件：
variation_x = Window.center[0] - self.initial_center[0]
variation_y = Window.center[1] - self.initial_center[1]
Window.left -= variation_x
Window.top -= variation_y
我不是Python / Kivy专家，所以这里可能需要做一些小改进，但是我认为这可以解决您的问题。