我有一些问题，因为我是 Python 和 Pyside 的新手。
我有 N 个进程同时在运行。
由于这些进程需要一些时间才能完成其工作，因此最终用户可能想要取消特定进程。所以我需要一种方法来了解进程的 ID，以便将此功能添加到程序中。
有一个answer在 Stackoverflow 中，这正是我正在做的。
代码如下:
#!/usr/bin/env python3
import multiprocessing, multiprocessing.pool, time, random, sys
from PySide.QtCore import *
from PySide.QtGui import *
def compute(num_row):
print("worker started at %d" % num_row)
random_number = random.randint(1, 10)
for second in range(random_number):
progress = float(second) / float(random_number) * 100
compute.queue.put((num_row, progress,))
time.sleep(1)
compute.queue.put((num_row, 100))
def pool_init(queue):
# see https://stackoverflow.com/a/3843313/852994
compute.queue = queue
class MainWindow(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.toolBar = self.addToolBar("Toolbar")
self.toolBar.addAction(QAction('Add Task', self, triggered=self.addTask))
self.table = QTableWidget()
self.table.verticalHeader().hide()
self.table.setColumnCount(2)
self.setCentralWidget(self.table)
# Pool of Background Processes
self.queue = multiprocessing.Queue()
self.pool = multiprocessing.Pool(processes=4, initializer=pool_init, initargs=(self.queue,))
# Check for progress periodically
self.timer = QTimer()
self.timer.timeout.connect(self.updateProgress)
self.timer.start(2000)
def addTask(self):
num_row = self.table.rowCount()
self.pool.apply_async(func=compute, args=(num_row,))
label = QLabel("Queued")
bar = QProgressBar()
bar.setValue(0)
self.table.setRowCount(num_row + 1)
self.table.setCellWidget(num_row, 0, label)
self.table.setCellWidget(num_row, 1, bar)
def updateProgress(self):
if self.queue.empty(): return
num_row, progress = self.queue.get() # unpack
print("received progress of %s at %s" % (progress, num_row))
label = self.table.cellWidget(num_row, 0)
bar = self.table.cellWidget(num_row, 1)
bar.setValue(progress)
if progress == 100:
label.setText('Finished')
elif label.text() == 'Queued':
label.setText('Downloading')
self.updateProgress() # recursion
if __name__ == '__main__':
app = QApplication(sys.argv)
main_window = MainWindow()
main_window.show()
sys.exit(app.exec_())
我添加了一个“停止”按钮，我知道如何获取表格中的选定行，但我不知道如何获取选定行的进程ID以终止。
更新 1:
为了让这更容易，我可以改变
multiprocessing.Pool(processes=4, initializer=pool_init, initargs=(self.queue,)) 到
multiprocessing.Pool(processes=1, initializer=pool_init, initargs=(self.queue,))
这样所有进程都必须等到一个进程结束
现在我们有一个进程在运行，其他进程在队列中，我如何才能只获得正在运行的进程的进程 ID？
请您参考如下方法:
我编写了一个或多或少重现多处理示例的演示，并添加了中止上传的功能。它一次只能处理六个并行上传，因为这是 QNetworkAccessManager 允许的最大值。但是，可以通过简单地添加另一个 QNetworkAccessManager 来增加此限制。
我在测试演示时遇到了一个问题。似乎在某些情况下，后数据可以发送两次(例如，参见 here)。但我不知道这是一个 Qt 错误，还是我的测试设置的问题(我使用了 python 线程 httpserver)。无论如何，通过关闭 uploadProgress 处理程序中的 reply-object 很容易修复(见下文)。
from PyQt4 import QtCore, QtGui, QtNetwork
class Window(QtGui.QWidget):
def __init__(self, address):
QtGui.QWidget.__init__(self)
self.address = address
self.table = QtGui.QTableWidget(self)
header = self.table.horizontalHeader()
header.setStretchLastSection(True)
header.hide()
self.table.setColumnCount(2)
self.button = QtGui.QPushButton('Add Upload', self)
self.button.clicked.connect(self.handleAddUpload)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.table)
layout.addWidget(self.button)
self.netaccess = QtNetwork.QNetworkAccessManager(self)
self._uploaders = {}
def handleAddUpload(self):
stream = QtCore.QFile('files/sample.tar.bz2')
if stream.open(QtCore.QIODevice.ReadOnly):
data = stream.readAll()
stream.close()
row = self.table.rowCount()
button = QtGui.QPushButton('Abort', self.table)
button.clicked.connect(lambda: self.handleAbort(row))
progress = QtGui.QProgressBar(self.table)
progress.setRange(0, len(data))
self.table.setRowCount(row + 1)
self.table.setCellWidget(row, 0, button)
self.table.setCellWidget(row, 1, progress)
uploader = self._uploaders[row] = Uploader(row, self.netaccess)
uploader.uploadProgress.connect(self.handleUploadProgress)
uploader.uploadFinished.connect(self.handleUploadFinished)
uploader.upload(data, self.address)
def handleUploadProgress(self, key, sent, total):
print('upload(%d): %d [%d]' % (key, sent, total))
progress = self.table.cellWidget(key, 1)
progress.setValue(sent)
def handleUploadFinished(self, key):
print('upload(%d) finished' % key)
button = self.table.cellWidget(key, 0)
button.setDisabled(True)
uploader = self._uploaders.pop(key)
uploader.deleteLater()
def handleAbort(self, key):
try:
self._uploaders[key].abort()
except (KeyError, AttributeError):
pass
class Uploader(QtCore.QObject):
uploadProgress = QtCore.pyqtSignal(object, int, int)
uploadFinished = QtCore.pyqtSignal(object)
def __init__(self, key, parent):
QtCore.QObject.__init__(self, parent)
self._key = key
self._reply = None
def abort(self):
if self._reply is not None:
self._reply.abort()
def upload(self, data, url):
if self._reply is None:
request = QtNetwork.QNetworkRequest(QtCore.QUrl(url))
request.setHeader(
QtNetwork.QNetworkRequest.ContentTypeHeader,
'application/x-www-form-urlencoded')
self._reply = self.parent().post(request, data)
self._reply.uploadProgress.connect(self.handleUploadProgress)
self._reply.finished.connect(self.handleFinished)
def handleUploadProgress(self, sent, total):
self.uploadProgress.emit(self._key, sent, total)
if sent >= total:
# prevent duplicated uploads
self._reply.close()
def handleFinished(self):
self._reply.deleteLater()
self._reply = None
self.uploadFinished.emit(self._key)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window('http://localhost:54321/upload')
window.setGeometry(500, 300, 500, 300)
window.show()
sys.exit(app.exec_())
