Pyqt 时时CPU使用情况

借鉴代码来自：https://github.com/hgoldfish/quickpanel

实现代码:

# -*- coding:utf-8 -*-
from __future__ import print_function
from __future__ import unicode_literals
from __future__ import division
from __future__ import absolute_import

import ctypes, sys
import ctypes.wintypes
from PyQt4.QtCore import QPoint, QRect, QTimer, Qt
from PyQt4.QtGui import QPainter, QPen, QPolygon, QApplication, QWidget

GetSystemTimes = ctypes.windll.kernel32.GetSystemTimes
class FILETIME(ctypes.Structure):
    _fields_ = [("dwLowDateTime", ctypes.wintypes.DWORD), ("dwHighDateTime", ctypes.wintypes.DWORD)]

    def __int__(self):
        # print(self.dwHighDateTime)
        return self.dwHighDateTime * 0x100000000 + self.dwLowDateTime
class MachineLoad:
    _instance = None

    @staticmethod
    def getInstance():
        if MachineLoad._instance is None:
            MachineLoad._instance = MachineLoad()
        return MachineLoad._instance

    def __init__(self):
        idle, kernel, user = FILETIME(), FILETIME(), FILETIME()
        GetSystemTimes(ctypes.byref(idle), ctypes.byref(kernel), ctypes.byref(user))
        self.idle0, self.kernel0, self.user0 = int(idle), int(kernel), int(user)

    def getLoad(self):
        idle, kernel, user = FILETIME(), FILETIME(), FILETIME()
        GetSystemTimes(ctypes.byref(idle), ctypes.byref(kernel), ctypes.byref(user))
        idle1, kernel1, user1 = int(idle), int(kernel), int(user)
        a, b, c = idle1 - self.idle0, kernel1 - self.kernel0, user1 - self.user0
        self.idle0, self.kernel0, self.user0 = idle1, kernel1, user1
        if (b + c) == 0:
            return 1
        return (b + c - a) / (b + c)

class MachineLoadWidget(QWidget):
    def __init__(self, parent):
        QWidget.__init__(self, parent)
        self.timer = QTimer()
        self.timer.timeout.connect(self.collectMachineLoad)
        self.loads = []
        self.maxLength = 400
        self.pointDistance = 5 #每点之间的间隔
        self.updateInterval = 500 #更新的时间间隔
        self.timer.setInterval(self.updateInterval)
        self.timer.start()
        self.machineLoad = MachineLoad.getInstance()
        self.boxWidth = 60

    def collectMachineLoad(self):
        rate = self.machineLoad.getLoad()
        self.loads.insert(0, rate)
        if len(self.loads) > self.maxLength:
            self.loads.pop(- 1)
        if self.isVisible():
            self.update()

    def paintEvent(self, event):
        QWidget.paintEvent(self, event)
        width, height = self.width(), self.height()
        polygon = QPolygon()
        for i, rate in enumerate(self.loads):
            x = width - i * self.pointDistance
            y = height - rate * height
            if x < self.boxWidth:
                break
            polygon.append(QPoint(x, y))
        painter = QPainter(self)
        pen = QPen()
        pen.setColor(Qt.darkGreen)
        painter.setPen(pen)
        painter.setRenderHint(QPainter.Antialiasing, True)
        #画网格
        painter.setOpacity(0.5)
        gridSize = self.pointDistance * 4
        deltaX = (width - self.boxWidth) % gridSize + self.boxWidth
        deltaY = height % gridSize
        for i in range(int(width / gridSize)):
            x = deltaX + gridSize * i
            painter.drawLine(x, 0, x, height)
        for j in range(int(height / gridSize)):
            y = j * gridSize + deltaY
            painter.drawLine(self.boxWidth, y, width, y)
        #画折线
        pen.setColor(Qt.darkCyan)
        pen.setWidth(2)
        painter.setPen(pen)
        painter.setOpacity(1)
        painter.drawPolyline(polygon)
        #画展示框
        if len(self.loads) > 0:
            rate = self.loads[0]
        else:
            rate = 1.0
        rect1 = QRect(4, height * 0.05, self.boxWidth - 9, height * 0.7)
        rect2 = QRect(4, height * 0.8, self.boxWidth - 9, height * 0.2)
        centerX = int(rect1.width() / 2) + 1
        pen.setWidth(1)
        for i in range(rect1.height()):
            if i % 4 == 0:
                continue
            if (rect1.height() - i) / rect1.height() > rate:
                pen.setColor(Qt.darkGreen)
            else:
                pen.setColor(Qt.green)
            painter.setPen(pen)
            for j in range(rect1.width()):
                if centerX - 1 <= j <= centerX + 1:
                    continue
                painter.drawPoint(rect1.x() + j, rect1.y() + i)
        pen.setColor(Qt.black)
        painter.setPen(pen)
        painter.drawText(rect2, Qt.AlignHCenter | Qt.AlignVCenter, str(int(rate * 100)) + "%")



class CPUstatus(QWidget):
    def __init__(self):
        super(CPUstatus, self).__init__()
        self.resize(200,200)
        self.factory = MachineLoadWidget(self)
        self.factory.resize(200, 200)


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

效果：