我有两个 Python 脚本需要相互通信。第一个是用 PySide2 制作的 GUI。 GUI 由用于控制蓝牙音频设备(播放、暂停、下一首、上一首等)的简单控件组成。这些命令使用我发现的第二个 python 脚本运行。第二个脚本是一个循环，它等待输入这些命令并在执行这些命令后做出响应。我对编程还很陌生，我猜这实际上是将前端与后端连接起来，但这是我以前从未做过的事情。
我编写了一个简化版的 GUI，只显示我需要的控件。 “后端”也在下面，但最初可以在这里找到:https://scribles.net/controlling-bluetooth-audio-on-raspberry-pi/
我之前问过类似的问题，@eyllanesc 在这里给出了可靠且有效的答案:Execute command to a Python script from separate Python script?但是，使用 QProcess 方法我无法弄清楚如何将 print 从后端输出到前端脚本。但是，错误消息可以正确打印。我曾尝试在后端使用 sys.stdout、process.read 的变体和 QByteArrays，但似乎无法进行任何操作。
我遇到的另一个问题是，只有在启动脚本之前连接了蓝牙设备，脚本才会起作用。如果我在它运行时断开连接并尝试重新连接，它将不再接受命令。如果还有一种方法可以监视设备是否正在播放/暂停，以便播放/暂停按钮可以根据设备状态进行更新，那也很有用，但在现阶段并不重要。
有多种方法可以完成，但我觉得最终将两个脚本集成到一个脚本中对我来说会更好，但我对任何可行的解决方案持开放态度。如果有人有任何建议或可以帮助我入门，我将不胜感激!
前端:
import sys
from PySide2.QtWidgets import *
class MainWindow(QWidget):
def __init__(self):
QWidget.__init__(self)
self.playbtn = QPushButton("Play")
self.nextbtn = QPushButton("Next")
self.prevbtn = QPushButton("Prev")
layout = QVBoxLayout()
layout.addWidget(self.playbtn)
layout.addWidget(self.nextbtn)
layout.addWidget(self.prevbtn)
self.setLayout(layout)
self.playbtn.released.connect(self.btnplay)
self.nextbtn.released.connect(self.btnnext)
self.prevbtn.released.connect(self.btnprev)
def btnplay(self): #play button turns into pause button upon being pressed
status = self.playbtn.text()
if status == "Play":
self.playbtn.setText("Pause")
print("Play Pressed")
elif status == "Pause":
self.playbtn.setText("Play")
print("Pause pressed")
def btnnext(self):
print("Next pressed")
def btnprev(self):
print("Prev pressed")
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()
后端:
import dbus, dbus.mainloop.glib, sys
from gi.repository import GLib
def on_property_changed(interface, changed, invalidated):
if interface != 'org.bluez.MediaPlayer1':
return
for prop, value in changed.items():
if prop == 'Status':
print('Playback Status: {}'.format(value))
elif prop == 'Track':
print('Music Info:')
for key in ('Title', 'Artist', 'Album'):
print(' {}: {}'.format(key, value.get(key, '')))
def on_playback_control(fd, condition):
str = fd.readline()
if str.startswith('play'):
player_iface.Play()
elif str.startswith('pause'):
player_iface.Pause()
elif str.startswith('next'):
player_iface.Next()
elif str.startswith('prev'):
player_iface.Previous()
elif str.startswith('vol'):
vol = int(str.split()[1])
if vol not in range(0, 128):
print('Possible Values: 0-127')
return True
transport_prop_iface.Set(
'org.bluez.MediaTransport1',
'Volume',
dbus.UInt16(vol))
return True
if __name__ == '__main__':
dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
bus = dbus.SystemBus()
obj = bus.get_object('org.bluez', "/")
mgr = dbus.Interface(obj, 'org.freedesktop.DBus.ObjectManager')
player_iface = None
transport_prop_iface = None
for path, ifaces in mgr.GetManagedObjects().items():
if 'org.bluez.MediaPlayer1' in ifaces:
player_iface = dbus.Interface(
bus.get_object('org.bluez', path),
'org.bluez.MediaPlayer1')
elif 'org.bluez.MediaTransport1' in ifaces:
transport_prop_iface = dbus.Interface(
bus.get_object('org.bluez', path),
'org.freedesktop.DBus.Properties')
if not player_iface:
sys.exit('Error: Media Player not found.')
if not transport_prop_iface:
sys.exit('Error: DBus.Properties iface not found.')
bus.add_signal_receiver(
on_property_changed,
bus_name='org.bluez',
signal_name='PropertiesChanged',
dbus_interface='org.freedesktop.DBus.Properties')
GLib.io_add_watch(sys.stdin, GLib.IO_IN, on_playback_control)
GLib.MainLoop().run()
2020 年 10 月 31 日更新:
我一直在研究我在上面链接的早期问题中建议的 QProcess 类。通过在按钮按下功能上使用它并在命令执行后添加 sys.exit ，它消除了始终连接设备的需要，但我仍然找不到接收的方法后端脚本的 print 输出。这也感觉像是一种非常肮脏的工作方式。它还保留了播放/暂停状态不会自动更新的问题。如果有人有任何建议，我将不胜感激!
import sys
import os.path
from PySide2.QtCore import *
from PySide2.QtWidgets import *
CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))
class MainWindow(QWidget):
def __init__(self):
QWidget.__init__(self)
self.playbtn = QPushButton("Play")
self.nextbtn = QPushButton("Next")
self.prevbtn = QPushButton("Prev")
layout = QVBoxLayout()
layout.addWidget(self.playbtn)
layout.addWidget(self.nextbtn)
layout.addWidget(self.prevbtn)
self.setLayout(layout)
self.playbtn.released.connect(self.btnplay)
self.nextbtn.released.connect(self.btnnext)
self.prevbtn.released.connect(self.btnprev)
def btnplay(self):
self.process = QProcess()
self.process.readyReadStandardError.connect(self.handle_readyReadStandardError)
self.process.readyReadStandardOutput.connect(self.handle_readyReadStandardOutput)
self.process.setProgram(sys.executable)
script_path = os.path.join(CURRENT_DIR, "test2.py")
self.process.setArguments([script_path])
self.process.start()
status = self.playbtn.text()
if status == "Play":
command = "play"
self.playbtn.setText("Pause")
print("play pressed")
elif status == "Pause":
command = "pause"
self.playbtn.setText("Play")
print("pause pressed")
msg = "{}\n".format(command)
self.process.write(msg.encode())
def btnnext(self):
self.process = QProcess()
self.process.readyReadStandardError.connect(self.handle_readyReadStandardError)
self.process.readyReadStandardOutput.connect(self.handle_readyReadStandardOutput)
self.process.setProgram(sys.executable)
script_path = os.path.join(CURRENT_DIR, "test2.py")
self.process.setArguments([script_path])
self.process.start()
command = "next"
msg = "{}\n".format(command)
self.process.write(msg.encode())
print("next pressed")
def btnprev(self):
self.process = QProcess()
self.process.readyReadStandardError.connect(self.handle_readyReadStandardError)
self.process.readyReadStandardOutput.connect(self.handle_readyReadStandardOutput)
self.process.setProgram(sys.executable)
script_path = os.path.join(CURRENT_DIR, "test2.py")
self.process.setArguments([script_path])
self.process.start()
command = "prev"
msg = "{}\n".format(command)
self.process.write(msg.encode())
print("prev pressed")
def handle_readyReadStandardError(self):
print(self.process.readAllStandardError().data().decode())
def handle_readyReadStandardOutput(self):
print(self.process.readAllStandardOutput().data().decode())
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()
最佳答案
恕我直言，OP 有一个 XY 问题，它给应用程序增加了不必要的复杂性，因为 dbus 事件循环可以与 Qt 事件循环共存，正如我在以下示例中所示:
import sys
import dbus
import dbus.mainloop.glib
from PyQt5 import QtCore, QtWidgets
class AudioManager(QtCore.QObject):
statusChanged = QtCore.pyqtSignal(str)
infoChanged = QtCore.pyqtSignal(dict)
def __init__(self, parent=None):
super().__init__(parent)
self._player_iface = None
self._transport_prop_iface = None
def initialize(self):
bus = dbus.SystemBus()
obj = bus.get_object("org.bluez", "/")
mgr = dbus.Interface(obj, "org.freedesktop.DBus.ObjectManager")
player_iface = None
transport_prop_iface = None
for path, ifaces in mgr.GetManagedObjects().items():
if "org.bluez.MediaPlayer1" in ifaces:
player_iface = dbus.Interface(
bus.get_object("org.bluez", path), "org.bluez.MediaPlayer1"
)
elif "org.bluez.MediaTransport1" in ifaces:
transport_prop_iface = dbus.Interface(
bus.get_object("org.bluez", path), "org.freedesktop.DBus.Properties"
)
if not player_iface:
raise Exception("Error: Media Player not found.")
if not transport_prop_iface:
raise Exception("Error: DBus.Properties iface not found.")
self._player_iface = player_iface
self._transport_prop_iface = transport_prop_iface
bus.add_signal_receiver(
self.handle_property_changed,
bus_name="org.bluez",
signal_name="PropertiesChanged",
dbus_interface="org.freedesktop.DBus.Properties",
)
def play(self):
self._player_iface.Play()
def pause(self):
self._player_iface.Pause()
def next(self):
self._player_iface.Next()
def previous(self):
self._player_iface.Previous()
def set_volume(self, Volume):
if Volume not in range(0, 128):
raise ValueError("Possible Values: 0-127")
self._transport_prop_iface.Set(
"org.bluez.MediaTransport1", "Volume", dbus.UInt16(vol)
)
def handle_property_changed(self, interface, changed, invalidated):
if interface != "org.bluez.MediaPlayer1":
return
for prop, value in changed.items():
if prop == "Status":
self.statusChanged.emit(value)
elif prop == "Track":
info = dict()
for key in ("Title", "Artist", "Album"):
info[key] = str(value.get(key, ""))
self.infoChanged.emit(info)
class MainWindow(QtWidgets.QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self._manager = AudioManager()
self._manager.infoChanged.connect(self.handle_info_changed)
self._manager.initialize()
self.playbtn = QtWidgets.QPushButton("Play")
self.nextbtn = QtWidgets.QPushButton("Next")
self.prevbtn = QtWidgets.QPushButton("Prev")
layout = QtWidgets.QVBoxLayout(self)
layout.addWidget(self.playbtn)
layout.addWidget(self.nextbtn)
layout.addWidget(self.prevbtn)
self.playbtn.released.connect(self._manager.play)
self.nextbtn.released.connect(self._manager.next)
self.prevbtn.released.connect(self._manager.previous)
def handle_info_changed(self, info):
print(info)
if __name__ == "__main__":
dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
app.exec_()
关于python - 将两个 Python 脚本集成为一个？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/64615035/