用于同时监视文件夹的多线程

Question

目前我正在尝试让 2 个按钮(几乎(同时运行。问题在于下面的代码，每个按钮本身运行良好，但是当两者都被选中时，只有第一个按钮运行。

import sys
from PyQt4.QtGui import *
from PyQt.QtCore import *
import os
import time
import traceback
class Worker(QRunnable):
def __init__(self, fn, *args, **kwargs):
super(Worker, self).__init__()
self.fn = fn
self.args = args
self.kwargs = kwargs

@pyqtSlot
def run(self):
try:
result = self.fn(*self.args, **self.kwargs)
except:
traceback.print_exc()
exctype, value = sys.exc_info()[:2]
self.signals.error.emit((exctype, value,  
traceback.format_exc()))
else:
self.signals.result.emit(result)
finally:
self.signals.finished.emit()
class MainWindow(QMainWindow):
def __init__(self, *args, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
layout = QVBoxLayout()
path =  "Paths to watch"
path2 = "Paths to watch"
self.b = QPushButton("Button1")
self.b.setCheckable(True)
self.b.pressed.connect(lambda: self.watcher(path))
self.b2 = QPushButton("Button1")
self.b2.setCheckable(True)
self.b2.pressed.connect(lambda: self.watcher(path2))
layout.addWidget(self.b)
layout.addWidget(self.b2)
w = QWidget()
w.setLayout(layout)
self.setCentralWidget(w)
self.threadpool = QThreadPool()
def watcher(self, s):
worker = Worker(self.monitor(s))
self.threadpool.start(worker)
def monitor(self, s):
before = dict([(f, None) for f in os.listdir(s)])
while 1:
QCoreApplication.processEvents()
after = dict([(f, None) for f in os.listdir(s)])
added = [f for f in after if not f in before]
removed = [f for f in before if not f in after]
if added: print "Added: ", ", ".join(added)
if removed: print "Deleted: ", ", ".join(removed)
before = after
app = QApplication([])
window = MainWindow()
app.exec_()

不确定我是否需要分配线程，或者我是否可以以某种方式让函数每 x 秒用计时器更新 GUI.. 或如何实现它

Answer 1

似乎您已经复制了代码并且您没有理解其操作，例如未定义signals，很明显信号是另一个类的对象，其任务是提供连接信号，另一方面@pyqtSlot中存在印刷错误，必须@pyqtSlot()。另一方面，该窗口将永远不会显示，因为您不调用show()方法，最后一个主要错误是您正在主线程中评估监视器函数，Worker 需要您传递函数而不求值，并且在该函数的参数旁边， 因此，您可以在辅助线程中调用它。

import sys
import os
import time
import traceback
from PyQt4.QtGui import *
from PyQt4.QtCore import *

class SignalHelper(QObject):
error = pyqtSignal(tuple)
result = pyqtSignal(object)
finished = pyqtSignal()
class Worker(QRunnable):
def __init__(self, fn, *args, **kwargs):
super(Worker, self).__init__()
self.fn = fn
self.args = args
self.kwargs = kwargs
self.signals = SignalHelper()
@pyqtSlot()
def run(self):
try:
result = self.fn(*self.args, **self.kwargs)
except:
traceback.print_exc()
exctype, value = sys.exc_info()[:2]
self.signals.error.emit((exctype, value,  
traceback.format_exc()))
else:
self.signals.result.emit(result)
finally:
self.signals.finished.emit()
class MainWindow(QMainWindow):
def __init__(self, *args, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
layout = QVBoxLayout()
path =  "Paths to watch"
path2 = "Paths to watch"
self.b = QPushButton("Button1")
self.b.setCheckable(True)
self.b.pressed.connect(lambda: self.watcher(path))
self.b2 = QPushButton("Button1")
self.b2.setCheckable(True)
self.b2.pressed.connect(lambda: self.watcher(path2))
layout.addWidget(self.b)
layout.addWidget(self.b2)
w = QWidget()
w.setLayout(layout)
self.setCentralWidget(w)
self.threadpool = QThreadPool()
def watcher(self, s):
worker = Worker(self.monitor, s)
self.threadpool.start(worker)
def monitor(self, s):
before = dict([(f, None) for f in os.listdir(s)])
while True:
after = dict([(f, None) for f in os.listdir(s)])
added = [f for f in after if not f in before]
removed = [f for f in before if not f in after]
if added: print("Added: ", ", ".join(added))
if removed: print("Deleted: ", ", ".join(removed))
before = after
if __name__ == '__main__':
app = QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())