发送终止后，Qthread不会停止

Question

以下代码的问题是工作线程在按下取消按钮后不会终止，def pdialog(self(直到while循环结束才停止。我想停止进度条打印进度，从而停止后台进程。

import sys
from PyQt4 import QtGui, QtCore
import time
#from t6 import Ui_dialog_progress
#from t6 import Ui_dialog_file
try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    _fromUtf8 = lambda s: s

class Ui_dialog_progress(object):
    def setupUi(self, dialog_progress):
        dialog_progress.setObjectName("dialog_progress")
        dialog_progress.resize(401, 165)
        self.gridLayout = QtGui.QGridLayout(dialog_progress)
        self.gridLayout.setObjectName("gridLayout")
        self.lblFileName = QtGui.QLabel(dialog_progress)
        self.lblFileName.setText("")
        self.lblFileName.setObjectName("lblFileName")
        self.gridLayout.addWidget(self.lblFileName, 0, 0, 1, 2)
        self.pbarFileSize = QtGui.QProgressBar(dialog_progress)
        self.pbarFileSize.setProperty("value", 0)
        self.pbarFileSize.setObjectName("pbarFileSize")
        self.gridLayout.addWidget(self.pbarFileSize, 1, 0, 1, 2)
        self.label_2 = QtGui.QLabel(dialog_progress)
        self.label_2.setObjectName("label_2")
        self.gridLayout.addWidget(self.label_2, 2, 0, 1, 1)
        self.pbarTotal = QtGui.QProgressBar(dialog_progress)
        self.pbarTotal.setProperty("value", 0)
        self.pbarTotal.setObjectName("pbarTotal")
        self.gridLayout.addWidget(self.pbarTotal, 3, 0, 1, 2)
        self.lblTotal = QtGui.QLabel(dialog_progress)
        self.lblTotal.setText("")
        self.lblTotal.setObjectName("lblTotal")
        self.gridLayout.addWidget(self.lblTotal, 4, 0, 1, 2)
        spacerItem = QtGui.QSpacerItem(213, 20, QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Minimum)
        self.gridLayout.addItem(spacerItem, 6, 0, 1, 1)
        spacerItem1 = QtGui.QSpacerItem(20, 5, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Expanding)
        self.gridLayout.addItem(spacerItem1, 5, 1, 1, 1)
        self.btnPbarCancel = QtGui.QPushButton(dialog_progress)
        self.btnPbarCancel.setObjectName("btnPbarCancel")
        self.gridLayout.addWidget(self.btnPbarCancel, 6, 1, 1, 1)
        self.retranslateUi(dialog_progress)
        QtCore.QMetaObject.connectSlotsByName(dialog_progress)
    def retranslateUi(self, dialog_progress):
        dialog_progress.setWindowTitle(QtGui.QApplication.translate("dialog_progress", "Dialog", None, QtGui.QApplication.UnicodeUTF8))
        self.label_2.setText(QtGui.QApplication.translate("dialog_progress", "Total:", None, QtGui.QApplication.UnicodeUTF8))
        self.btnPbarCancel.setText(QtGui.QApplication.translate("dialog_progress", "Cancel", None, QtGui.QApplication.UnicodeUTF8))
class Ui_dialog_file(object):
    def setupUi(self, dialog_file):
        dialog_file.setObjectName(_fromUtf8("dialog_file"))
        dialog_file.resize(101, 59)
        self.btnCreate = QtGui.QPushButton(dialog_file)
        self.btnCreate.setGeometry(QtCore.QRect(10, 20, 77, 25))
        self.btnCreate.setObjectName(_fromUtf8("btnCreate"))
        self.retranslateUi(dialog_file)
        QtCore.QMetaObject.connectSlotsByName(dialog_file)
    def retranslateUi(self, dialog_file):
        dialog_file.setWindowTitle(QtGui.QApplication.translate("dialog_file", "file", None, QtGui.QApplication.UnicodeUTF8))
        self.btnCreate.setText(QtGui.QApplication.translate("dialog_file", "Create", None, QtGui.QApplication.UnicodeUTF8))
class ProgressDialog(QtGui.QDialog):
    def __init__(self, parent=None):
        QtGui.QDialog.__init__(self, parent = None)
        self.ui = Ui_dialog_progress()
        self.ui.setupUi(self)
        self.setWindowModality(QtCore.Qt.ApplicationModal)
class MyThread(QtCore.QThread):
    trigger = QtCore.pyqtSignal()
    updatePD = QtCore.pyqtSignal()
    def __init__(self, parent=None):
        super(MyThread, self).__init__(parent)
    def run(self):
        self.trigger.emit()
class Main(QtGui.QDialog):
    def __init__(self, parent=None):
        super(Main, self).__init__(parent)
        self.ui = Ui_dialog_file()
        self.ui.setupUi(self)
        self.ui.btnCreate.clicked.connect(self.start_threads)
    def start_threads(self):
        self.mythread = MyThread(self)
        self.mythread.trigger.connect(self.pdialog)
        self.connect(self.mythread, QtCore.SIGNAL("updateFileProgress(int)"), self.updateFileProgress)
        self.connect(self.mythread, QtCore.SIGNAL("updateTotalProgress(int)"), self.updateTotalProgress)
        self.pd = ProgressDialog()
        signal = QtCore.SIGNAL("clicked()")
        self.pd.ui.btnPbarCancel.connect(self.pd.ui.btnPbarCancel, signal, self.abort)
        self.mythread.start()
    def abort(self):
        self.pd.close()
        self.mythread.terminate()
    def updateFileProgress(self, j):
        self.pd.ui.pbarFileSize.setValue(j)
        print j
    def updateTotalProgress(self, i):
        self.pd.ui.pbarTotal.setValue(i)
        print i
    def pdialog(self):
        self.pd.show()
        i = 1
        self.pd.ui.pbarTotal.setValue(0)
        self.pd.ui.pbarFileSize.setValue(0)
        j = 1
        while i < 100:
            while j <= 100:
                time.sleep(0.01)
                self.mythread.emit(QtCore.SIGNAL("updateFileProgress(int)"), j)
                QtGui.qApp.processEvents()
                j += 1
            i += 1
            j = 1
            self.mythread.emit(QtCore.SIGNAL("updateTotalProgress(int)"), i)
            QtGui.qApp.processEvents()
        self.pd.close()
if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    mainwindow = Main()
    mainwindow.show()
    sys.exit(app.exec_())

Answer 1

不要使用terminate()来终止线程。

请参阅http://qt-project.org/doc/qt-4.8/qthread.html#terminate

void Q线程：：terminate(([插槽]

终止线程的执行。线程可以立即终止，也可以不立即终止，这取决于操作系统调度策略。在terminate((之后使用QThread:：wait((进行同步终止。

当线程终止时，所有等待线程完成的线程都将被唤醒。

警告：此功能很危险，不鼓励使用。线程可以在其代码路径中的任何点终止。修改数据时可以终止线程。线程没有机会在自己之后进行清理、解锁任何持有的互斥锁等。简而言之，只有在绝对必要的情况下才使用此函数。

有很多温和的方法可以停止线程
例如，您可以使用标志变量来通知您的辅助功能停止。

def start_threads(self):
    self.end_flag = False
    self.mythread = MyThread(self)
    self.mythread.trigger.connect(self.pdialog)
    self.connect(self.mythread, QtCore.SIGNAL("updateFileProgress(int)"), self.updateFileProgress)
    self.connect(self.mythread, QtCore.SIGNAL("updateTotalProgress(int)"), self.updateTotalProgress)
    self.pd = ProgressDialog()
    signal = QtCore.SIGNAL("clicked()")
    self.pd.ui.btnPbarCancel.connect(self.pd.ui.btnPbarCancel, signal, self.abort)
    self.mythread.start()
def abort(self):
    self.pd.close()
    #self.mythread.terminate()
    self.end_flag = True
def pdialog(self):
    self.pd.show()
    i = 1
    self.pd.ui.pbarTotal.setValue(0)
    self.pd.ui.pbarFileSize.setValue(0)
    j = 1
    while i < 100:
        while j <= 100:
            if self.end_flag:
                self.pd.close()
                return
            time.sleep(0.01)
            self.mythread.emit(QtCore.SIGNAL("updateFileProgress(int)"), j)
            QtGui.qApp.processEvents()
            j += 1
        i += 1
        j = 1
        self.mythread.emit(QtCore.SIGNAL("updateTotalProgress(int)"), i)
        QtGui.qApp.processEvents()
    self.pd.close()