Python Pyqt4-QProgressBar如何在函数循环处理数据时指示每次

它第一次起作用，但在重新调用处理数据的循环函数时不再起作用。我有两个python程序。main显示进度条，第二个循环围绕处理数据。我对stackoverflow和google进行了全面的研究，并努力寻找解决方案。最接近的解决方案是“QProgressBar完成加载2后出现无法解释的延迟”问题，但我无法将其应用于我的问题。我还尝试应用QApplication.processEvents（），但没有成功

主程序。。。等等

def connectDevice(self)
  if self.usb_serial != None:
    self.ui.ProgressBar.setMinimum(0)  # settings for showing pyqt4 progress bar            
    self.ui.ProgressBar.setMaximum(0)  # not indicating as expected          
    self.ui.ProgressBar.setValue(0)    # first showing 0%
    self.device = ScopeDev(self.usb_serial)   # device.py my second Python program
    self.device.start()                       # Connect Call... class ScopeDev/def run(self):
    self.device.init_received.connect(self.init_received)     # end of data processing signal received
  else:
    self.Display_MSG("Connection Error", "device not plug into USB port." )

def reprocessdata(self):
  logging.info("Re-Processing Data...")
  self.ui.ProgressBar.setMaximum(0)     # hoping to kick off the progress bar again. Not even showing 0% 
  self.ui.ProgressBar.setValue(0)       # I tried insert QApplication.processEvents() here but did not work
  self.device.init()                    # Call class ScopeDev/def init(self): data was being processed

def init_received(self):
  logging.debug("Init received")
  self.ui.ProgressBar.setMaximum(1)         # indicated 100% on both times, when data processing completed
  self.ui.ProgressBar.setValue(1)           # first from connectDevice and second time from reprocessdata

class ScopeDev (QtCore.QThread):
  init_received = QtCore.pyqtSignal()

def __init__(self, usb_serial, usb_serial_baud=9600, timeout=2):
  QtCore.QThread.__init__(self, None)
  self.serial = serial.Serial(usb_serial, usb_serial_baud, timeout=timeout)   # connect to Arduino
  logging.debug("Connected (%s)" % usb_serial)

def run(self):
  self.init()                    #1 Call...def init(self):

def init(self):
  self.serial.readline().rstrip()            # read println put out by Arduino/plaser.ino
  self.serial.write(b'init')                    
  self.sread(expect=b'^done_init$')

def sread(self, expect=b'^cmd$'):   # loops around to process data from Arduino...etc. when completed...
  self.init_received.emit()       # emits the outbound signal back to the main

我的第二个python程序。。。等等

def connectDevice(self)
  if self.usb_serial != None:
    self.ui.ProgressBar.setMinimum(0)  # settings for showing pyqt4 progress bar            
    self.ui.ProgressBar.setMaximum(0)  # not indicating as expected          
    self.ui.ProgressBar.setValue(0)    # first showing 0%
    self.device = ScopeDev(self.usb_serial)   # device.py my second Python program
    self.device.start()                       # Connect Call... class ScopeDev/def run(self):
    self.device.init_received.connect(self.init_received)     # end of data processing signal received
  else:
    self.Display_MSG("Connection Error", "device not plug into USB port." )

def reprocessdata(self):
  logging.info("Re-Processing Data...")
  self.ui.ProgressBar.setMaximum(0)     # hoping to kick off the progress bar again. Not even showing 0% 
  self.ui.ProgressBar.setValue(0)       # I tried insert QApplication.processEvents() here but did not work
  self.device.init()                    # Call class ScopeDev/def init(self): data was being processed

def init_received(self):
  logging.debug("Init received")
  self.ui.ProgressBar.setMaximum(1)         # indicated 100% on both times, when data processing completed
  self.ui.ProgressBar.setValue(1)           # first from connectDevice and second time from reprocessdata

class ScopeDev (QtCore.QThread):
  init_received = QtCore.pyqtSignal()

def __init__(self, usb_serial, usb_serial_baud=9600, timeout=2):
  QtCore.QThread.__init__(self, None)
  self.serial = serial.Serial(usb_serial, usb_serial_baud, timeout=timeout)   # connect to Arduino
  logging.debug("Connected (%s)" % usb_serial)

def run(self):
  self.init()                    #1 Call...def init(self):

def init(self):
  self.serial.readline().rstrip()            # read println put out by Arduino/plaser.ino
  self.serial.write(b'init')                    
  self.sread(expect=b'^done_init$')

def sread(self, expect=b'^cmd$'):   # loops around to process data from Arduino...etc. when completed...
  self.init_received.emit()       # emits the outbound signal back to the main

---

以下是一些建议：

第一个在所有删除第一个初始化中，这三行：

self.ui.ProgressBar.setMinimum(0)  # settings for showing pyqt4 progress bar            
self.ui.ProgressBar.setMaximum(0)  # not indicating as expected          
self.ui.ProgressBar.setValue(0)    # first showing 0%

这是默认情况下完成的

第二步要做的事情：在

重新处理数据中

尝试切换这两行：

  self.ui.ProgressBar.setMaximum(0)        
  self.ui.ProgressBar.setValue(0)

3.使用前两行，尝试用以下命令重置进度条：

void QProgressBar:：reset（）[插槽]

重置进度条。进度条“倒带”并显示“否” 进步

在您的情况下：

self.ui.ProgressBar.reset（）

---

-我不明白的是，为什么要使用进度条？因为您只有两种状态—0（0%）和1（100%）

，所以需要一个

QTimer

来每隔X秒更新gui一次错误调用

exec（）

，然后进入事件循环。而您重新实现的

run

缺少这一点，因此您的线程没有事件循环，因此没有信号或插槽。见文章。谢谢JBernardo。我的进度条设置为范围（0,0）。因此，当函数sread（）在我的第二个程序中循环时，它将始终指示。我不是在更新酒吧。setvalue（0）。多亏了gatto，它指示介于start（）和第一次从第二个程序线程收到的信号之间。但在函数reprocesdata（）中使用after时不工作。我必须在第一次跑步后退出最后一步，然后再次开始吗？我在第二个程序中的函数sread（）的循环末尾发emmiting，认为线程结束了？我在这里真的有困难，即使在阅读了所有的类引用并试图理解线程之后？我一直在尝试，但没有成功，bar在第一次数据处理运行期间指出，GUI响应良好。但在第二次和后续数据重新处理时，GUI栏被冻结（无响应）