当 Qwidget 的背景颜色发生变化时，程序随机崩溃

Question

设置背景颜色很好，但我的界面有一个Qwidget，可以在某个时候改变其背景颜色。这将导致程序崩溃，当我注释掉变色代码时崩溃停止。

下面的代码肯定会在运行一段时间后崩溃。

import sys
from PySide2.QtWidgets import QWidget,QPushButton,QApplication,QListWidget,QGridLayout,
QLabel,QMainWindow,QLineEdit,QScrollArea,QVBoxLayout,QMessageBox
from PySide2.QtCore import QTimer,QDateTime,QSize,Qt
from PySide2.QtGui import *
import requests,json
import configparser #
import os
import time
import threading #
from pynput import keyboard #
import requests,json
from math import * 
from functools import partial
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.resize(320,100)    
self.setWindowTitle('aaaa')
self.setStyleSheet("QMainWindow
{
background-color:white;
color:white;
margin:0px
}")
self.InitializeWindow()
self.i=0
def InitializeWindow(self):
self.statebar=QWidget(self)
self.statebar.setGeometry(0, 40, 320, 54)
print(sys._getframe().f_lineno)
self.statebar.setStyleSheet("QWidget{background-color:#1EC5CD}")
self.th_countdown=threading.Thread(target=self.countdown,args=())
self.th_countdown.setDaemon(True)
self.th_countdown.start()
self.message_main=QLabel(self.statebar)
self.message_main.setGeometry(150,7,40,37)
self.message_main.setStyleSheet("background:transparent;color:white;margin:0px;font-size:45px;font-weight:bold")
self.message_main.setWordWrap(True)
self.message_main.hide()
self.message_main.setAlignment(Qt.AlignTop|Qt.AlignLeft)
self.message_signature=QLabel(self.statebar)
self.message_signature.setGeometry(50,6,42,42)
self.message_signature.setScaledContents(True)
self.message_signature.setStyleSheet("background:transparent")
self.message_result=QLabel(self.statebar)
self.message_result.setGeometry(150,6,160,25)
self.message_result.setStyleSheet("background:transparent;color:white;margin:0px;font-size:24px;font-weight:bold")
self.message_result.setWordWrap(True)
self.message_result.hide()
self.message_detail=QLabel(self.statebar)
self.message_detail.setGeometry(150,34,160,15)
self.message_detail.setStyleSheet("background:transparent;color:white;margin:0px;font-size:14px")
self.message_detail.setWordWrap(True)
self.message_detail.hide()
def bind(self, ret):
self.message_result.show()
self.message_detail.show()
self.message_main.hide()
if(ret%2==0):
self.statebar.setStyleSheet("QWidget{background-color:#1EC5CD}") ##FA6400
self.message_result.setText(str(ret))
self.message_detail.setText(str(ret))
else:
self.statebar.setStyleSheet("QWidget{background-color:#FA6400}") ##FA6400
self.message_result.setText(str(ret))
self.message_detail.setText(str(ret))
def countdown(self):
while(1):
time.sleep(0.2)
self.i=self.i+1
self.bind(self.i)
if __name__ == '__main__':
app = 0
app = QApplication(sys.argv)
win = MainWindow()
#icon = QIcon()
#icon.addPixmap(QPixmap("./res/mdm.ico"),QIcon.Normal, QIcon.Off)
#win.setWindowIcon(icon)
win.show()
sys.exit(app.exec_())
pass

有时python 会抛出一条错误消息"无法解析对象的样式表..."，有时它只是崩溃而没有消息。

Answer 1

倒计时方法在修改 GUI 的 GUI 以外的线程上运行，并且该操作不安全，因为 2 个线程无法访问导致您指出的问题的同一资源。解决方案不是直接从另一个线程修改 GUI，而是通过线程安全的信号：

import sys
import time
import threading
from PySide2.QtCore import Qt, Signal, Slot
from PySide2.QtWidgets import QApplication, QLabel, QMainWindow, QWidget

class MainWindow(QMainWindow):
valueChanged = Signal(int)
def __init__(self):
super(MainWindow, self).__init__()
self.resize(320, 100)
self.setWindowTitle("aaaa")
self.setStyleSheet(
"""
QMainWindow
{
background-color:white;
color:white;
margin:0px
}
"""
)
self.InitializeWindow()
self.i = 0
self.valueChanged.connect(self.bind)
def InitializeWindow(self):
self.statebar = QWidget(self)
self.statebar.setGeometry(0, 40, 320, 54)
print(sys._getframe().f_lineno)
self.statebar.setStyleSheet("QWidget{background-color:#1EC5CD}")
self.th_countdown = threading.Thread(target=self.countdown)
self.th_countdown.setDaemon(True)
self.th_countdown.start()
self.message_main = QLabel(self.statebar)
self.message_main.setGeometry(150, 7, 40, 37)
self.message_main.setStyleSheet(
"background:transparent;color:white;margin:0px;font-size:45px;font-weight:bold"
)
self.message_main.setWordWrap(True)
self.message_main.hide()
self.message_main.setAlignment(Qt.AlignTop | Qt.AlignLeft)
self.message_signature = QLabel(self.statebar)
self.message_signature.setGeometry(50, 6, 42, 42)
self.message_signature.setScaledContents(True)
self.message_signature.setStyleSheet("background:transparent")
self.message_result = QLabel(self.statebar)
self.message_result.setGeometry(150, 6, 160, 25)
self.message_result.setStyleSheet(
"background:transparent;color:white;margin:0px;font-size:24px;font-weight:bold"
)
self.message_result.setWordWrap(True)
self.message_result.hide()
self.message_detail = QLabel(self.statebar)
self.message_detail.setGeometry(150, 34, 160, 15)
self.message_detail.setStyleSheet(
"background:transparent;color:white;margin:0px;font-size:14px"
)
self.message_detail.setWordWrap(True)
self.message_detail.hide()
@Slot(int)
def bind(self, ret):
self.message_result.show()
self.message_detail.show()
self.message_main.hide()
qss = "QWidget{background-color:%s}" % (
"#1EC5CD" if ret % 2 == 0 else "#FA6400"
)
self.statebar.setStyleSheet(qss)
self.message_result.setNum(ret)
self.message_detail.setNum(ret)
def countdown(self):
while True:
time.sleep(0.2)
self.i += 1
self.valueChanged.emit(self.i)

if __name__ == "__main__":
app = QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())