用Python編寫Android應用界面的方法

隨着Android手機用戶的不斷增加，Android應用的開發變得越來越受歡迎。不僅Java等編程語言能夠開發Android應用，Python也有自己的一套方法來進行Android應用的開發。Python能夠讓開發者更加方便、快速地創建Android應用程序，下面就來詳細介紹一下Python的Android應用界面編寫方法。

一、PyQt5簡介

PyQt是Python語言的GUI編程工具包，它是做為對Qt界面開發工具的Python-binding實現。PyQt5是PyQt的最新版本，支持Python3，支持Python常用的圖形界面開發工具Qt5。因此，如果要開發Python編寫的Android應用界面，推薦使用PyQt5。

二、製作Android應用程序界面的方法

1. 安裝Python-for-Android以及PyQt5

首先，需要在Android手機上安裝Python-for-Android、PyQt5以及QtforPython（也稱為PySide2），這樣才能確保Python 能夠與Qt及其它庫相互配合。可以通過下面的命令行來安裝：

$ pip install PySide2
$ pip install PyQt5
$ pip install android

2. 編寫Python代碼

通過PyQt5，可以使用Python編寫Android應用程序的界面。以下是一個簡單的Python程序:

from PySide2.QtCore import *
from PySide2.QtGui import *
from PySide2.QtWidgets import *

class MyWidget(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('Hello World')
        layout = QVBoxLayout(self)
        label = QLabel('Hello World', self)
        label.setAlignment(Qt.AlignCenter)
        layout.addWidget(label)

if __name__ == '__main__':
    app = QApplication()
    widget = MyWidget()
    widget.show()
    app.exec_()

這個程序簡單地創建了一個窗口和一個標籤，在標籤中顯示「Hello World」文本。

3. 打包發佈應用

使用buildozer打包PyQt5應用程序為Android應用程序，可以使用一個名為buildozer.spec文件中的一組指令。這個文件包括應用程序的所有來源和組件的配置。以下是buildozer.spec文件中必需的指令範例：

[app]
# (str) Title of your application
title = My Application

# (str) Package name
package.name = myapp

# (str) Package domain (needed for android/ios packaging)
package.domain = org.test

# (str) Source code where the main.py live
source.dir = .

# (list) List of source files to includes into the package
source.include_exts = py,png,jpg,kv,atlas

# (list) List of inclusions using pattern matching
#source.include_patterns = assets/*,images/*.png

# (list) List of exclusions using pattern matching
#source.exclude_patterns = tests/*,bin/*/*,.*/*,*/RCS/*

# (str) Application versioning (method 1)
# version = 0.1

# (str) Application versioning (method 2)
# version.regex = __version__ = ['"](.*)['"]
# version.filename = %(source.dir)s/main.py

# (list) Application requirements
# comma separated e.g. requirements = sqlite3,kivy
#requirements = kivy

# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# If it's one of our recipes, will set the recipe
#requirements.source.kivy = ../../kivy

# (list) Garden Requirements
#garden_requirements =

# (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

# (str) Supported orientation (one of landscape, sensorLandscape, portrait or all)
orientation = portrait

# (bool) Indicate if the application should be fullscreen or not
fullscreen = 0

# (bool) Try to bypass Android permissions
android.permissions = INTERNET

# (str) Primary color of the application
android.primary_color = #50D1AA

# (str) Secondary color of the application
android.secondary_color = #50D1BB

# (str) Accent color of the application
#android.accent_color =

# (bool) Show or not the debug panel
#android.debug = False

# (list) Permissions
#android.permissions =

# (list) features (adds uses-feature -tags to manifest)
#android.features =

# (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, x86_64
# Defaults to armeabi-v7a for backwards compatibility.
android.arch = armeabi-v7a

# (str) Sequence of one or more ant commands to apply before packaging
#android.prebuild_cmd =

# (str) Path to a custom toolchain if defined. It must contain the following four files:
#    bin/arm-linux-androideabi-gcc
#    bin/arm-linux-androideabi-g++
#    include/python2.7/pyconfig.h
#    libs/armeabi-v7a/libpython2.7.so
#android.toolchain = /opt/android-toolchain-arm

# (str) Path to a custom NDK directory (if empty, it's assumed the NDK is in PATH)
#android.ndk_path =

# (list) Flags for the compiler
#android.custom_cflags =

# (list) Linker flags
#android.custom_ldflags =

# (list) Othe pyinstaller bootloader options (https://pythonhosted.org/PyInstaller/usage.html)
#p4a.bootloader.bootces = ces64
#p4a.bootloader.name = mybootloader

# (int) Number of workers to run the python for android build process
#android.numeric_version = 0

# (str) The version of the NDK to use
#android.ndk_version = 'r9c'

# (int) Which toolchain to use. Choices: 0 (default), 1 or 2
#android.toolchain_version = 0

# (str) If defined, set the ANDROIDSDK environment variable to the path
#android.sdk_path =

# (str) If defined, set the ANDROIDNDK environment variable to the path
#android.ndk_path = /usr/local/android-ndk-r9

# (str) If defined, set the ANDROIDAPI environment variable to the API level
android.api = 27

# (str) NDK extra options to specify
#android.ndk_options = "ndk-toolchain=clang"

# (str) The branch of sdl2 to use
#android.sdl2_branch = master

# (bool) If True, then no local python is built, and the native libs
# are copied from the host.
#android.copy_local_libs = False

# (list) Whitelist of packages to include from the Python build
#android.whitelist =

# (list) Blacklist of packages to ommit from the build
#android.blacklist =

# (list) List of Java .jar files to add to the build of the final .apk.
#android.add_jars = foo.jar,bar.jar,path/to/more.jar

# (list) List of Java folders to add to the build of the final .apk.
#android.add_java_dir = foo,bar,path/to/more

# (list) A list of Java classes to compile against, e.g. org.w3c.dom
#android.add_compile_exts = my_java_ext

# (str) Path to a custom prebuilt .so/.a to add to the libs/armeabi. Can be in tree or external.
#android.add_libs_armeabi = foo.so,bar.a,path/to/more

# (bool) Use –bootstrap to attempt to build the bootstrap dependencies
#android.bootstrap = sdl2

# (str) work around for alleged SDL2 bug on android
# see http://www.kivy.org/docs/helP/android.html#buildozer-spec
#android.setup_mode = False

三、總結

通過以上所述方法，我們可以快速的開發一個Python編寫的Android應用程序，運用Python語言，加上強大的PyQt5工具包等，該方法能夠在程序開發過程中大幅提升開發效率，同時還能讓Python這門語言能夠在Android應用開發中大展身手。