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：