PyQt5实现下载进度条效果

# -*- coding: utf-8 -*-  from PyQt5 import QtCore, QtGui, QtWidgets from PyQt5.Qt import Qt  class Ui_download(object):   def setupUi(self, Dialog):     Dialog.setWindowFlags(Qt.FramelessWindowHint)     Dialog.setObjectName("Dialog")     Dialog.resize(300, 56)     Dialog.setFixedSize(Dialog.width(), Dialog.height())     sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)     sizePolicy.setHorizontalStretch(0)     sizePolicy.setVerticalStretch(0)     sizePolicy.setHeightForWidth(Dialog.sizePolicy().hasHeightForWidth())     Dialog.setSizePolicy(sizePolicy)     Dialog.setSizeGripEnabled(True)     self.gridLayout = QtWidgets.QGridLayout(Dialog)     self.gridLayout.setSizeConstraint(QtWidgets.QLayout.SetDefaultConstraint)     self.gridLayout.setObjectName("gridLayout")     self.progressBar = QtWidgets.QProgressBar(Dialog)     self.progressBar.setProperty("value", 0)     self.progressBar.setAlignment(QtCore.Qt.AlignLeading|QtCore.Qt.AlignLeft|QtCore.Qt.AlignVCenter)     self.progressBar.setObjectName("progressBar")     self.gridLayout.addWidget(self.progressBar, 1, 0, 1, 1)     self.label = QtWidgets.QLabel(Dialog)     self.label.setObjectName("label")     self.gridLayout.addWidget(self.label, 0, 0, 1, 1)      self.retranslateUi(Dialog)     QtCore.QMetaObject.connectSlotsByName(Dialog)    def retranslateUi(self, Dialog):     _translate = QtCore.QCoreApplication.translate     Dialog.setWindowTitle(_translate("Dialog", "Dialog"))     self.label.setText(_translate("Dialog", "客户端更新下载中..."))   if __name__ == "__main__":   import sys   app = QtWidgets.QApplication(sys.argv)   Dialog = QtWidgets.QDialog()   ui = Ui_download()   ui.setupUi(Dialog)   Dialog.show()   sys.exit(app.exec_())

# -*- coding: utf-8 -*-  """ Module implementing Dialog. """  from PyQt5.QtCore import QThread, pyqtSignal from PyQt5.QtWidgets import QDialog from PyQt5 import QtWidgets from Ui_download import Ui_download import os import sys import requests   class downloadThread(QThread):    download_proess_signal = pyqtSignal(int)    def __init__(self, download_url, filesize, fileobj, buffer):     super(downloadThread, self).__init__()     self.download_url = download_url     self.filesize = filesize     self.fileobj = fileobj     self.buffer = buffer    def run(self):     try:       f = requests.get(self.download_url, stream=True)       offset = 0       for chunk in f.iter_content(chunk_size=self.buffer):         if not chunk:           break         self.fileobj.seek(offset)         self.fileobj.write(chunk)         offset = offset + len(chunk)         proess = offset / int(self.filesize) * 100         self.download_proess_signal.emit(int(proess))       self.fileobj.close()       self.exit(0)     except Exception as e:       print(e)   class download(QDialog, Ui_download):   """   下载类实现   """   def __init__(self, download_url, auto_close=True, parent=None):     """     Constructor          @download_url:下载地址     @auto_close:下载完成后时候是否需要自动关闭     """     super(download, self).__init__(parent)     self.setupUi(self)     self.progressBar.setValue(0)     self.downloadThread = None     self.download_url = download_url     self.filesize = None     self.fileobj = None     self.auto_close = auto_close     self.download()    def download(self):     self.filesize = requests.get(self.download_url, stream=True).headers['Content-Length']     path = os.path.join("update", os.path.basename(self.download_url))     self.fileobj = open(path, 'wb')     self.downloadThread = downloadThread(self.download_url, self.filesize, self.fileobj, buffer=10240)     self.downloadThread.download_proess_signal.connect(self.change_progressbar_value)     self.downloadThread.start()    def change_progressbar_value(self, value):     self.progressBar.setValue(value)     if self.auto_close and value == 100:       self.close()   if __name__ == '__main__':   app = QtWidgets.QApplication(sys.argv)   ui = download()   ui.show()   sys.exit(app.exec_())