Kivy App（来自 buldozer）不显示根屏幕
Kivy App (from buldozer) not displaying root screen
尝试使用以下方法构建一个非常简单的 Android 应用程序：
- Buildozer 版本 0.39
- Python v3.7.1 或 v2.7.15（同样的问题）
- Kivy v1.11.0.dev0
- PythonForAndroid（硕士截至 2019 年 5 月 26 日）
- Cython v0.29.7
- Ubuntu 18.04
Python代码：
from kivy.app import App
from kivy.uix.button import Button
import logging
class StartUpBugApp(App):
__version__ = '1.00' # for buildozer
def build(self):
self.logger = logging.getLogger(__name__)
return Button(text='button')
def on_start(self):
self.logger.critical('In on_start')
print('In on_start', flush=True)
def on_stop(self):
self.logger.critical('In on_stop')
print('In on_stop', flush=True)
def on_pause(self):
self.logger.critical('In on_pause')
print('In on_pause', flush=True)
return True
def on_resume(self):
self.logger.critical('In on_resume')
print('In on_resume', flush=True)
if __name__ == '__main__':
StartUpBugApp().run()
buildozer.spec:
[app]
# (str) Title of your application
title = "StartupBug"
# (str) Package name
package.name = startupbug
# (str) Package domain (needed for android/ios packaging)
package.domain = org.jra
# (str) Source code where the main.py live
source.dir = /home/jra/PycharmProjects/StartUpBug
# (list) Source files to include (let empty to include all the files)
source.include_exts = py
# (list) List of inclusions using pattern matching
#source.include_patterns = assets/*,images/*.png
# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec
source.exclude_exts = spec, p4a, txt, csh, cvsignore, sh, exe, log, basis, tar, bak, directory
# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin
# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg
# (str) Application versioning (method 1)
version = 1.00
# (str) Application versioning (method 2)
# version.regex = __version__ = ['"](.*)['"]
# version.filename = %(source.dir)s/main.py
# (list) Application requirements
# comma seperated e.g. requirements = sqlite3,kivy
requirements = python3, kivy
# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# requirements.source.kivy = ../../kivy
# (list) Garden requirements
#garden_requirements =
#garden_requirements = filebrowser
# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png
# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png
#icon.filename = %(source.dir)s/resources/hearts48.png
# (str) Supported orientation (one of landscape, portrait or all)
orientation = landscape
# (list) List of service to declare
#services = NAME:ENTRYPOINT_TO_PY,NAME2:ENTRYPOINT2_TO_PY
#
# OSX Specific
#
#
# author = © Copyright Info
# change the major version of python used by the app
osx.python_version = 2
# Kivy version to use
osx.kivy_version = 1.9.1
#
# Android specific
#
# (bool) Indicate if the application should be fullscreen or not
fullscreen = 1
# (string) Presplash background color (for new android toolchain)
# Supported formats are: #RRGGBB #AARRGGBB or one of the following names:
# red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray,
# darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy,
# olive, purple, silver, teal.
#android.presplash_color = #FFFFFF
# (list) Permissions
#android.permissions = INTERNET
# (int) Android API to use
# Samsung Galaxy Tab: Android 8.1.0, API 27
android.api = 27
# (int) Minimum API required
android.minapi = 24
# (int) Android SDK version to use
#android.sdk = 20
# (str) Android NDK version to use
#android.ndk = 9c
# (bool) Use --private data storage (True) or --dir public storage (False)
#android.private_storage = True
# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path = /home/jra/Android/android-ndk-r9c
# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path = /home/jra/Android/Sdk
# (str) ANT directory (if empty, it will be automatically downloaded.)
#android.ant_path =
# (bool) If True, then skip trying to update the Android sdk
# This can be useful to avoid excess Internet downloads or save time
# when an update is due and you just want to test/build your package
# android.skip_update = False
# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity
# (list) Pattern to whitelist for the whole project
#android.whitelist =
# (str) Path to a custom whitelist file
#android.whitelist_src =
# (str) Path to a custom blacklist file
#android.blacklist_src =
# (list) List of Java .jar files to add to the libs so that pyjnius can access
# their classes. Don't add jars that you do not need, since extra jars can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar
# (list) List of Java files to add to the android project (can be java or a
# directory containing the files)
#android.add_src =
# (list) Android AAR archives to add (currently works only with sdl2_gradle
# bootstrap)
#android.add_aars =
# (list) Gradle dependencies to add (currently works only with sdl2_gradle
# bootstrap)
# android.gradle_dependencies = 'com.android.support:appcompat-v7:26.1.0'
# (str) python-for-android branch to use, defaults to master
#p4a.branch = stable
# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME
# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png
# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =
# (str) launchMode to set for the main activity
#android.manifest.launch_mode = singleInstance
# (list) Android additionnal libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
#android.add_libs_armeabi_v7a = libs/android-v7/*.so
#android.add_libs_x86 = libs/android-x86/*.so
#android.add_libs_mips = libs/android-mips/*.so
# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
android.wakelock = True
# (list) Android application meta-data to set (key=value format)
#android.meta_data =
# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =
# (str) Android logcat filters to use
#android.logcat_filters = *:S python:D
# (bool) Copy library instead of making a libpymodules.so
#android.copy_libs = 1
# (str) The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86
# Samsung Galaxy arch: armeabi-v7a, armeabi
android.arch = armeabi-v7a
#android.arch = x86
#
# Python for android (p4a) specific
#
# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)
p4a.source_dir = /home/jra/Downloads/Python4android_may_26_2019/python-for-android-master
# (str) The directory in which python-for-android should look for your own build recipes (if any)
#p4a.local_recipes =
# (str) Filename to the hook for p4a
#p4a.hook =
# (str) Bootstrap to use for android builds
# p4a.bootstrap = sdl2
#
# iOS specific
#
# (str) Path to a custom kivy-ios folder
#ios.kivy_ios_dir = ../kivy-ios
# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"
# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s
[buildozer]
# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 2
# (int) Display warning if buildozer is run as root (0 = False, 1 = True)
warn_on_root = 1
# (str) Path to build artifact storage, absolute or relative to spec file
# build_dir = /build/hearts
# (str) Path to build output (i.e. .apk, .ipa) storage
# bin_dir = ./bin
# -----------------------------------------------------------------------------
# List as sections
#
# You can define all the "list" as [section:key].
# Each line will be considered as a option to the list.
# Let's take [app] / source.exclude_patterns.
# Instead of doing:
#
#[app]
#source.exclude_patterns = license,data/audio/*.wav,data/images/original/*
#
# This can be translated into:
#
#[app:source.exclude_patterns]
#license
#data/audio/*.wav
#data/images/original/*
#
# -----------------------------------------------------------------------------
# Profiles
#
# You can extend section / key with a profile
# For example, you want to deploy a demo version of your application without
# HD content. You could first change the title to add "(demo)" in the name
# and extend the excluded directories to remove the HD content.
#
#[app@demo]
#title = My Application (demo)
#
#[app:source.exclude_patterns@demo]
#images/hd/*
#
# Then, invoke the command line with the "demo" profile:
#
#buildozer --profile demo android debug
我必须按照这个问题中的描述修改 p4a master 中的 _android.pyx： 以避免关于 JAVA_NAMESPACE（字节与字符串）的旧错误。已替换
python_act = autoclass(JAVA_NAMESPACE + u'.PythonActivity')
与：
python_act = autoclass("org/kivy/android/PythonActivity")
但是现在应用程序启动并且不显示Button。这是 logcat:
的一些日志输出
2019-05-26 14:51:59.695 30549-30899/org.jra.startupbug I/python: In on_start
2019-05-26 14:51:59.695 30549-30899/org.jra.startupbug I/python: In on_start
2019-05-26 14:51:59.696 30549-30899/org.jra.startupbug I/python: [WARNING] [Base ] Unknown <android> provider
2019-05-26 14:51:59.697 30549-30899/org.jra.startupbug I/python: [INFO ] [Base ] Start application main loop
2019-05-26 14:51:59.702 4090-4905/? V/WindowManager: Relayout Window{a2ee1a1 u0 org.jra.startupbug/org.kivy.android.PythonActivity}: viewVisibility=0 req=1920x1200 WM.LayoutParams{(0,0)(fillxfill) sim=#20 ty=1 fl=#1810500 pfl=0x20000 fmt=-3 wanim=0x1030001 vsysui=0x1706 sysuil=true needsMenuKey=2 colorMode=0 naviIconColor=0}
2019-05-26 14:51:59.704 30549-30899/org.jra.startupbug I/python: [INFO ] [GL ] NPOT texture support is available
2019-05-26 14:51:59.714 30549-30549/org.jra.startupbug D/ViewRootImpl@813b3af[PythonActivity]: Relayout returned: old=[0,0][1920,1200] new=[0,0][1920,1200] result=0x1 surface={valid=true 3357532160} changed=false
2019-05-26 14:51:59.730 2603-2603/? D/SurfaceFlinger: Display[0] configurations (* current):
* 0: 1200x1920, xdpi=225.776993, ydpi=225.776993, refresh=16666666
numHwLayers=2, flags=00000000
type | handle | hint | flag | tr | blnd | format | source crop (l,t,r,b) | frame | name
-----------+----------+------+------+----+------+-------------+--------------------------------+------------------------+------
GLES | 00000000 | 0000 | 0220 | 04 | 0105 | ? ffffffff | 0.0, 0.0, -1.0, -1.0 | 0, 0, 1200, 1920 | Background for - SurfaceView - org.jra.startupbug/org.kivy.android.PythonActivity@ec3983e@0[30549]#0
FB TARGET | f5683600 | 0000 | 0000 | 00 | 0105 | RGBA_8888 | 0.0, 0.0, 1200.0, 1920.0 | 0, 0, 1200, 1920 | HWC_FRAMEBUFFER_TARGET
2019-05-26 14:51:59.761 2603-2603/? E/SurfaceFlinger: [SurfaceView - org.jra.startupbug/org.kivy.android.PythonActivity@ec3983e@0[30549]#0] rejecting buffer: bufWidth=1920, bufHeight=1164, front.active.{w=1920, h=1200}
如果我将应用程序最小化，然后将其放大，我会看到预期的 on_pause 和 on_resume，然后应用程序会正确显示。 ideas/suggestions 关于如何让应用程序正确显示而无需 minimize/maximize?
我发现了一个解决问题的丑陋技巧。我只是使用 ScreenManager，并创建一个没有实际用途的虚拟 Screen。我设置虚拟Screen为初始Screen，并使用Clock.schedule_once()切换到真正的主屏幕。似乎工作正常（SlideTransition 效果除外）。我怀疑我可以使用 kivy.uix.screenmanager.NoTransition 来最小化任何过渡效果。
修改后的代码如下：
from kivy.app import App
from kivy.clock import Clock
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen, NoTransition
class StartUpBugApp(App):
__version__ = '1.00' # for buildozer
def build(self):
self.sm = ScreenManager(transition=NoTransition())
# dummy screen (not actually used)
screen1 = Screen(name='screen1')
screen1.add_widget(Button(text='button1', on_release=self.switchToScreen2))
self.sm.add_widget(screen1)
# actual desired initial Screen
screen2 = Screen(name='screen2')
screen2.add_widget(Button(text='button2', on_release=self.switchToScreen1))
self.sm.add_widget(screen2)
# schedule changing to desired initial `Screen`
Clock.schedule_once(self.switchToScreen2)
return self.sm
def switchToScreen2(self, *args):
self.sm.current = 'screen2'
def switchToScreen1(self, *args):
self.sm.current = 'screen1'
def on_start(self):
print('In on_start')
def on_stop(self):
print('In on_stop')
def on_pause(self):
print('In on_pause')
return True
def on_resume(self):
print('In on_resume')
if __name__ == '__main__':
StartUpBugApp().run()
尝试使用以下方法构建一个非常简单的 Android 应用程序：
- Buildozer 版本 0.39
- Python v3.7.1 或 v2.7.15（同样的问题）
- Kivy v1.11.0.dev0
- PythonForAndroid（硕士截至 2019 年 5 月 26 日）
- Cython v0.29.7
- Ubuntu 18.04
Python代码：
from kivy.app import App
from kivy.uix.button import Button
import logging
class StartUpBugApp(App):
__version__ = '1.00' # for buildozer
def build(self):
self.logger = logging.getLogger(__name__)
return Button(text='button')
def on_start(self):
self.logger.critical('In on_start')
print('In on_start', flush=True)
def on_stop(self):
self.logger.critical('In on_stop')
print('In on_stop', flush=True)
def on_pause(self):
self.logger.critical('In on_pause')
print('In on_pause', flush=True)
return True
def on_resume(self):
self.logger.critical('In on_resume')
print('In on_resume', flush=True)
if __name__ == '__main__':
StartUpBugApp().run()
buildozer.spec:
[app]
# (str) Title of your application
title = "StartupBug"
# (str) Package name
package.name = startupbug
# (str) Package domain (needed for android/ios packaging)
package.domain = org.jra
# (str) Source code where the main.py live
source.dir = /home/jra/PycharmProjects/StartUpBug
# (list) Source files to include (let empty to include all the files)
source.include_exts = py
# (list) List of inclusions using pattern matching
#source.include_patterns = assets/*,images/*.png
# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec
source.exclude_exts = spec, p4a, txt, csh, cvsignore, sh, exe, log, basis, tar, bak, directory
# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin
# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg
# (str) Application versioning (method 1)
version = 1.00
# (str) Application versioning (method 2)
# version.regex = __version__ = ['"](.*)['"]
# version.filename = %(source.dir)s/main.py
# (list) Application requirements
# comma seperated e.g. requirements = sqlite3,kivy
requirements = python3, kivy
# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# requirements.source.kivy = ../../kivy
# (list) Garden requirements
#garden_requirements =
#garden_requirements = filebrowser
# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png
# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png
#icon.filename = %(source.dir)s/resources/hearts48.png
# (str) Supported orientation (one of landscape, portrait or all)
orientation = landscape
# (list) List of service to declare
#services = NAME:ENTRYPOINT_TO_PY,NAME2:ENTRYPOINT2_TO_PY
#
# OSX Specific
#
#
# author = © Copyright Info
# change the major version of python used by the app
osx.python_version = 2
# Kivy version to use
osx.kivy_version = 1.9.1
#
# Android specific
#
# (bool) Indicate if the application should be fullscreen or not
fullscreen = 1
# (string) Presplash background color (for new android toolchain)
# Supported formats are: #RRGGBB #AARRGGBB or one of the following names:
# red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray,
# darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy,
# olive, purple, silver, teal.
#android.presplash_color = #FFFFFF
# (list) Permissions
#android.permissions = INTERNET
# (int) Android API to use
# Samsung Galaxy Tab: Android 8.1.0, API 27
android.api = 27
# (int) Minimum API required
android.minapi = 24
# (int) Android SDK version to use
#android.sdk = 20
# (str) Android NDK version to use
#android.ndk = 9c
# (bool) Use --private data storage (True) or --dir public storage (False)
#android.private_storage = True
# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path = /home/jra/Android/android-ndk-r9c
# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path = /home/jra/Android/Sdk
# (str) ANT directory (if empty, it will be automatically downloaded.)
#android.ant_path =
# (bool) If True, then skip trying to update the Android sdk
# This can be useful to avoid excess Internet downloads or save time
# when an update is due and you just want to test/build your package
# android.skip_update = False
# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity
# (list) Pattern to whitelist for the whole project
#android.whitelist =
# (str) Path to a custom whitelist file
#android.whitelist_src =
# (str) Path to a custom blacklist file
#android.blacklist_src =
# (list) List of Java .jar files to add to the libs so that pyjnius can access
# their classes. Don't add jars that you do not need, since extra jars can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar
# (list) List of Java files to add to the android project (can be java or a
# directory containing the files)
#android.add_src =
# (list) Android AAR archives to add (currently works only with sdl2_gradle
# bootstrap)
#android.add_aars =
# (list) Gradle dependencies to add (currently works only with sdl2_gradle
# bootstrap)
# android.gradle_dependencies = 'com.android.support:appcompat-v7:26.1.0'
# (str) python-for-android branch to use, defaults to master
#p4a.branch = stable
# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME
# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png
# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =
# (str) launchMode to set for the main activity
#android.manifest.launch_mode = singleInstance
# (list) Android additionnal libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
#android.add_libs_armeabi_v7a = libs/android-v7/*.so
#android.add_libs_x86 = libs/android-x86/*.so
#android.add_libs_mips = libs/android-mips/*.so
# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
android.wakelock = True
# (list) Android application meta-data to set (key=value format)
#android.meta_data =
# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =
# (str) Android logcat filters to use
#android.logcat_filters = *:S python:D
# (bool) Copy library instead of making a libpymodules.so
#android.copy_libs = 1
# (str) The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86
# Samsung Galaxy arch: armeabi-v7a, armeabi
android.arch = armeabi-v7a
#android.arch = x86
#
# Python for android (p4a) specific
#
# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)
p4a.source_dir = /home/jra/Downloads/Python4android_may_26_2019/python-for-android-master
# (str) The directory in which python-for-android should look for your own build recipes (if any)
#p4a.local_recipes =
# (str) Filename to the hook for p4a
#p4a.hook =
# (str) Bootstrap to use for android builds
# p4a.bootstrap = sdl2
#
# iOS specific
#
# (str) Path to a custom kivy-ios folder
#ios.kivy_ios_dir = ../kivy-ios
# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"
# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s
[buildozer]
# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 2
# (int) Display warning if buildozer is run as root (0 = False, 1 = True)
warn_on_root = 1
# (str) Path to build artifact storage, absolute or relative to spec file
# build_dir = /build/hearts
# (str) Path to build output (i.e. .apk, .ipa) storage
# bin_dir = ./bin
# -----------------------------------------------------------------------------
# List as sections
#
# You can define all the "list" as [section:key].
# Each line will be considered as a option to the list.
# Let's take [app] / source.exclude_patterns.
# Instead of doing:
#
#[app]
#source.exclude_patterns = license,data/audio/*.wav,data/images/original/*
#
# This can be translated into:
#
#[app:source.exclude_patterns]
#license
#data/audio/*.wav
#data/images/original/*
#
# -----------------------------------------------------------------------------
# Profiles
#
# You can extend section / key with a profile
# For example, you want to deploy a demo version of your application without
# HD content. You could first change the title to add "(demo)" in the name
# and extend the excluded directories to remove the HD content.
#
#[app@demo]
#title = My Application (demo)
#
#[app:source.exclude_patterns@demo]
#images/hd/*
#
# Then, invoke the command line with the "demo" profile:
#
#buildozer --profile demo android debug
我必须按照这个问题中的描述修改 p4a master 中的 _android.pyx：
python_act = autoclass(JAVA_NAMESPACE + u'.PythonActivity')
与：
python_act = autoclass("org/kivy/android/PythonActivity")
但是现在应用程序启动并且不显示Button。这是 logcat:
2019-05-26 14:51:59.695 30549-30899/org.jra.startupbug I/python: In on_start
2019-05-26 14:51:59.695 30549-30899/org.jra.startupbug I/python: In on_start
2019-05-26 14:51:59.696 30549-30899/org.jra.startupbug I/python: [WARNING] [Base ] Unknown <android> provider
2019-05-26 14:51:59.697 30549-30899/org.jra.startupbug I/python: [INFO ] [Base ] Start application main loop
2019-05-26 14:51:59.702 4090-4905/? V/WindowManager: Relayout Window{a2ee1a1 u0 org.jra.startupbug/org.kivy.android.PythonActivity}: viewVisibility=0 req=1920x1200 WM.LayoutParams{(0,0)(fillxfill) sim=#20 ty=1 fl=#1810500 pfl=0x20000 fmt=-3 wanim=0x1030001 vsysui=0x1706 sysuil=true needsMenuKey=2 colorMode=0 naviIconColor=0}
2019-05-26 14:51:59.704 30549-30899/org.jra.startupbug I/python: [INFO ] [GL ] NPOT texture support is available
2019-05-26 14:51:59.714 30549-30549/org.jra.startupbug D/ViewRootImpl@813b3af[PythonActivity]: Relayout returned: old=[0,0][1920,1200] new=[0,0][1920,1200] result=0x1 surface={valid=true 3357532160} changed=false
2019-05-26 14:51:59.730 2603-2603/? D/SurfaceFlinger: Display[0] configurations (* current):
* 0: 1200x1920, xdpi=225.776993, ydpi=225.776993, refresh=16666666
numHwLayers=2, flags=00000000
type | handle | hint | flag | tr | blnd | format | source crop (l,t,r,b) | frame | name
-----------+----------+------+------+----+------+-------------+--------------------------------+------------------------+------
GLES | 00000000 | 0000 | 0220 | 04 | 0105 | ? ffffffff | 0.0, 0.0, -1.0, -1.0 | 0, 0, 1200, 1920 | Background for - SurfaceView - org.jra.startupbug/org.kivy.android.PythonActivity@ec3983e@0[30549]#0
FB TARGET | f5683600 | 0000 | 0000 | 00 | 0105 | RGBA_8888 | 0.0, 0.0, 1200.0, 1920.0 | 0, 0, 1200, 1920 | HWC_FRAMEBUFFER_TARGET
2019-05-26 14:51:59.761 2603-2603/? E/SurfaceFlinger: [SurfaceView - org.jra.startupbug/org.kivy.android.PythonActivity@ec3983e@0[30549]#0] rejecting buffer: bufWidth=1920, bufHeight=1164, front.active.{w=1920, h=1200}
如果我将应用程序最小化，然后将其放大，我会看到预期的 on_pause 和 on_resume，然后应用程序会正确显示。 ideas/suggestions 关于如何让应用程序正确显示而无需 minimize/maximize?
我发现了一个解决问题的丑陋技巧。我只是使用 ScreenManager，并创建一个没有实际用途的虚拟 Screen。我设置虚拟Screen为初始Screen，并使用Clock.schedule_once()切换到真正的主屏幕。似乎工作正常（SlideTransition 效果除外）。我怀疑我可以使用 kivy.uix.screenmanager.NoTransition 来最小化任何过渡效果。
修改后的代码如下：
from kivy.app import App
from kivy.clock import Clock
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen, NoTransition
class StartUpBugApp(App):
__version__ = '1.00' # for buildozer
def build(self):
self.sm = ScreenManager(transition=NoTransition())
# dummy screen (not actually used)
screen1 = Screen(name='screen1')
screen1.add_widget(Button(text='button1', on_release=self.switchToScreen2))
self.sm.add_widget(screen1)
# actual desired initial Screen
screen2 = Screen(name='screen2')
screen2.add_widget(Button(text='button2', on_release=self.switchToScreen1))
self.sm.add_widget(screen2)
# schedule changing to desired initial `Screen`
Clock.schedule_once(self.switchToScreen2)
return self.sm
def switchToScreen2(self, *args):
self.sm.current = 'screen2'
def switchToScreen1(self, *args):
self.sm.current = 'screen1'
def on_start(self):
print('In on_start')
def on_stop(self):
print('In on_stop')
def on_pause(self):
print('In on_pause')
return True
def on_resume(self):
print('In on_resume')
if __name__ == '__main__':
StartUpBugApp().run()