从线程监视CPU活动中更新进度栏

Question

我从我的代码中获取此错误：

RuntimeWarning: MetaObjectBuilder::addMethod: Invalid method signature provided for "CPU_VALUE"
  self.threadclass.CPU_VALUE.connect(SIGNAL('CPU_VALUE'), self.UpdateProgressBar)

from PySide2 import QtWidgets, QtCore
from PySide2.QtCore import SIGNAL, Signal
import main
import sysinfo


class MainUiClass(main.Ui_MainWindow, QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MainUiClass, self).__init__(parent)
        self.setupUi(self)
        self.threadclass = ThreadClass()
        self.threadclass.start()
        self.threadclass.CPU_VALUE.connect(SIGNAL('CPU_VALUE'), self.UpdateProgressBar)
        # self.UpdateProgressBar()

    def UpdateProgressBar(self):
        val = sysinfo.getCPU()
        self.progressBar.setValue(val)


class CpuClass(QtCore.QObject):
    cpu = Signal()


class ThreadClass(QtCore.QThread):
    CPU_VALUE = CpuClass()
    cpu = Signal()

    def __init__(self, parent=None):
        super(ThreadClass, self).__init__(parent)

    def run(self):
        while 1:
            # val = sysinfo.getCPU()
            self.CPU_VALUE.emit(SIGNAL('CPU_VALUE'), sysinfo.getCPU())
            # print(val)


if __name__ == '__main__':
    app = QtWidgets.QApplication([])
    a = MainUiClass()
    a.show()
    app.exec_()

sysinfo文件：

import psutil

def getCPU():
    return psutil.cpu_percent(interval=1)

Answer 1

您的示例有几个问题。首先，您正在混合旧式和新型信号，这令人困惑且不必要。旧式信号绝不能在新应用中使用。其次，您使用的是信号对象（cpusignal），这是不必要的，因为可以在qthread类上直接定义信号。第三，您不会在信号中散发CPU百分比的值，因此进度条将永远不会更新。最后，您尚未提供清洁线程关闭线程的机制。

在下面的演示脚本中，上述所有问题已经解决，我还添加了一个simulator类来生成用于测试的CPU活动。单击测试按钮将产生大约二十秒的活动，然后将相应地更新进度栏：

import psutil
from PySide2 import QtWidgets, QtCore
from PySide2.QtCore import Signal

class MainUiClass(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.progress = QtWidgets.QProgressBar()
        self.button = QtWidgets.QPushButton('Test')
        self.button.clicked.connect(self.handleButton)
        layout = QtWidgets.QHBoxLayout(self)
        layout.addWidget(self.progress)
        layout.addWidget(self.button)
        self.monitor = CpuMonitor()
        self.monitor.cpuPercent.connect(self.progress.setValue)
        self.monitor.start()
        self.simulator = Simulator()

    def handleButton(self):
        if not self.simulator.isRunning():
            self.simulator.start()

    def closeEvent(self, event):
        for thread in self.simulator, self.monitor:
            thread.stop()
            thread.quit()
            thread.wait()

class CpuMonitor(QtCore.QThread):
    cpuPercent = Signal(int)

    def run(self):
        self._stopped = False
        while not self._stopped:
            value = int(psutil.cpu_percent(interval=1))
            self.cpuPercent.emit(value)

    def stop(self):
        self._stopped = True

class Simulator(QtCore.QThread):
    def run(self):
        self._stopped = False
        random = QtCore.QRandomGenerator.system()
        timer1 = QtCore.QDeadlineTimer(20000)
        while not self._stopped and not timer1.hasExpired():
            duration = random.bounded(400, 800)
            self.msleep(duration)
            timer2 = QtCore.QDeadlineTimer(duration)
            while not self._stopped and not timer2.hasExpired():
                pass

    def stop(self):
        self._stopped = True

if __name__ == '__main__':

    app = QtWidgets.QApplication(['CPU Monitor'])
    a = MainUiClass()
    a.show()
    app.exec_()