Python程序带有QT 5设计师未与crontab -e一起启动启动

Question

当Raspberry Pi使用crontab -e启动时，我正在尝试运行我的Python程序。 该代码将QT5设计器用于小部件，我认为这就是为什么我启动它时没有运行的原因。

该代码正常运行良好，但这只是我尝试从启动运行它的情况下它不起作用。

这是错误消息：

qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Aborted

这是我的python代码：

import sys
from PyQt5.QtCore import pyqtSlot
from PyQt5.QtWidgets import QApplication,QDialog
from PyQt5.uic import loadUi
import RPi.GPIO as gpio
import time

time.sleep(20)

fan=19
door=26
LED=24

gpio.setmode(gpio.BCM)
gpio.setwarnings(False)
gpio.setup(fan,gpio.OUT)
gpio.setup(door,gpio.OUT)
gpio.setup(LED,gpio.OUT)


class HMI(QDialog):
    def __init__(self):
        super(HMI, self).__init__()
        loadUi('design.ui',self)
        
        self.setWindowTitle('HMI System')
        self.btn.clicked.connect(self.fan_toggle)
        self.doorBtn.clicked.connect(self.door_toggle)
        self.LEDbtn.clicked.connect(self.LED_toggle)
        
    @pyqtSlot()
    def fan_toggle (self):
        if gpio.input(fan):
            gpio.output(fan,gpio.LOW)
            self.btn.setText('Fan')
            self.btn.setStyleSheet('QPushButton{ background-color: rgb(60,60,60) ; color: white;}')
        else:
            gpio.output(fan, gpio.HIGH)
            self.btn.setText('Fan')
            self.btn.setStyleSheet('QPushButton{ background-color: red; color: white;}')
            
            
    @pyqtSlot()    
    def door_toggle (self):
        if gpio.input(door):
            gpio.output(door,gpio.LOW)
            self.doorBtn.setStyleSheet('QPushButton{ background-color: rgb(60,60,60) ; color: white;}')
            self.doorBtn.setText('Door')
            
        else:
            gpio.output(door, gpio.HIGH)
            self.doorBtn.setStyleSheet('QPushButton{ background-color: red; color: white;}')
            self.doorBtn.setText('Opening..')
            time.sleep(7)
            gpio.output(door,gpio.LOW)
            self.doorBtn.setStyleSheet('QPushButton{ background-color: rgb(60,60,60) ; color: white;}')
            self.doorBtn.setText('Door')
            
    @pyqtSlot()
    def LED_toggle (self):
        if gpio.input(LED):
            gpio.output(LED,gpio.LOW)
            self.LEDbtn.setText('LED')
            self.LEDbtn.setStyleSheet('QPushButton{ background-color: rgb(60,60,60) ; color: white;}')
        else:
            gpio.output(LED, gpio.HIGH)
            self.LEDbtn.setText('LED')
            self.LEDbtn.setStyleSheet('QPushButton{ background-color: red; color: white;}')
            
            
            
            
            
            
app=QApplication(sys.argv)
widget=HMI()
widget.show()
sys.exit(app.exec_())

如果有什么区别，我也在远程桌面上这样做？ 但它也连接到一个小型监视器。

谢谢您的任何帮助！

Answer 1

显示管理器应首先在该PYQT应用程序可以查看其GUI之前开始。
您可以将（.diskTop）文件添加到〜/.config/autostart/之类的示例中：

[Desktop Entry]
Comment=BlaBlaBla
Exec=python3 /path/to/python_script.py
Icon=absolute_path_to_icon
Name=MyPyQtApp
Terminal=false
Hidden=false

when the system boots => then the user type his password => then clicks "login":-
the App will automatically run