PyQT細分錯誤（有時）

Question

我創建一個界面來管理一些服務器，如重新啟動服務的基本功能，並且認為這樣的，我做的界面QTCreator中和編程PyQT5 ，它的正常工作（有時）。

有時它也可以正常工作，其他時候我遇到Segmentation Fault或QObject::connect: Cannot queue arguments of type 'QTextCursor' (Make sure 'QTextCursor' is registered using qRegisterMetaType().)

當我在MainWindow單擊restart_nginx時發生，可能是線程管理出現問題，這是我正在使用PyQT/QT的第一個項目

謝謝。

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from __future__ import unicode_literals

import paramiko
import threading

from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from ui_mainwindow import Ui_MainWindow

servers = {
    "Mars": "198.58.112.***",
    "Saturn": "198.58.116.***"
}

green = "rgb(83, 236, 17)"
default = "rgb(154, 154, 154)"
yellow = "yellow"
red = "red"
pw = 'pass'

def format_status(color):
    return "background-color: " + color + "; border: 1px solid black;"

class Worker(QObject):

    def __init__(self, ui, server, command=None, sudo=False, *args, **kwargs):
        QObject.__init__(self, *args, **kwargs)

        self.ssh = paramiko.SSHClient()
        self.ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

        self.ui = ui
        self.command = command
        self.sudo = sudo
        self.server = server

    finished = pyqtSignal()

    @pyqtSlot()
    def execute(self):

        self.ui.status_restart_nginx.setStyleSheet(format_status(color=yellow))

        try:

            self.ssh.connect(self.server, username='hercules', password=pw)

        except paramiko.SSHException as e:

            self.ui.log.append("ERRO: Impossible to connect: %s", e)
            self.ui.status_restart_nginx.setStyleSheet(format_status(color=red))

        try:

            session = self.ssh.get_transport().open_session()
            session.get_pty()

            f = session.makefile()

            session.exec_command("ls -lh")

            #if self.sudo:
            #    session.send(pw + '\n')

            for line in f.readlines():
                self.ui.log.append(line)

            f.close()

            self.ssh.close()

            self.ui.status_restart_nginx.setStyleSheet(format_status(color=green))

        except Exception as e:
            self.ui.status_restart_nginx.setStyleSheet(format_status(color=red))
            print 'errinho: ', e

        self.finished.emit()

class MainWindow(QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None, **kwargs):
        super(MainWindow, self).__init__(parent)
        self.setupUi(self)

        self.btn_restart_nginx.clicked.connect(self.restart_nginx)

        self.thread_worker = None
        self.obj_worker = None

    def create_worker(self, server, command=None, sudo=False):

        self.thread_worker = QThread(parent = self)
        self.obj_worker = Worker(ui = self, server = server, command = command, sudo = sudo)
        self.obj_worker.moveToThread(self.thread_worker)
        self.obj_worker.finished.connect(self.thread_worker.quit)
        self.thread_worker.started.connect(self.obj_worker.execute)
        self.thread_worker.start()

    def restart_nginx(self):

        self.status_restart_nginx.setStyleSheet(format_status(color=yellow))

        self.log.append("(Mars) Nginx: trying to restart front-end...")

        self.create_worker(servers["Mars"], command = "sudo service nginx restart", sudo = True)

if __name__=="__main__":

    from sys import argv, exit

    app = QApplication(argv)

    m = MainWindow()
    m.show()
    m.raise_()

    exit(app.exec_())

Answer 1

切勿嘗試從工作線程內對GUI進行更改。 僅從主GUI線程中更新GUI，並且不將對GUI元素的引用傳遞給工作線程。

在GUI線程和輔助線程之間進行通信的最簡單，最安全的方法是發出自定義信號 。 當信號以這種方式在線程之間發出時 ，它們將排隊，一旦控制權返回到事件循環，該插槽就會在接收者的線程中被調用。

在PyQt的，也通常建議使用pyqtSlot裝飾跨線程進行連接時，在列出的原因， 這個答案 。