Python PySide和進度條線程

Question

我有這個代碼：

from PySide import QtCore, QtGui
import time

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(400, 133)
        self.progressBar = QtGui.QProgressBar(Dialog)
        self.progressBar.setGeometry(QtCore.QRect(20, 10, 361, 23))
        self.progressBar.setProperty("value", 24)
        self.progressBar.setObjectName("progressBar")
        self.pushButton = QtGui.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(20, 40, 361, 61))
        self.pushButton.setObjectName("pushButton")

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(QtGui.QApplication.translate("Dialog", "Dialog", None, QtGui.QApplication.UnicodeUTF8))
        self.pushButton.setText(QtGui.QApplication.translate("Dialog", "PushButton", None, QtGui.QApplication.UnicodeUTF8))
        self.progressBar.setValue(0)
        self.pushButton.clicked.connect(self.progress)

    def progress(self):
        self.progressBar.minimum = 1
        self.progressBar.maximum = 100
        for i in range(1, 101):
            self.progressBar.setValue(i)
            time.sleep(0.1)

if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    sys.exit(app.exec_())

我希望在一個單獨的線程中有進度條，所以它不會凍結應用程序，但我似乎無法找到如何這樣做。

有人可以幫忙嗎？

Answer 1

我想你可能弄錯了。 您希望在單獨的線程中執行的工作因此不會凍結應用程序。 但您也希望能夠更新進度條。 您可以通過使用QThread創建工作類來實現此目的。 QThreads能夠發出信號，您的UI可以監聽並采取適當的行動。

首先，讓我們創建你的工人類。

#Inherit from QThread
class Worker(QtCore.QThread):

    #This is the signal that will be emitted during the processing.
    #By including int as an argument, it lets the signal know to expect
    #an integer argument when emitting.
    updateProgress = QtCore.Signal(int)

    #You can do any extra things in this init you need, but for this example
    #nothing else needs to be done expect call the super's init
    def __init__(self):
        QtCore.QThread.__init__(self)

    #A QThread is run by calling it's start() function, which calls this run()
    #function in it's own "thread". 
    def run(self):
        #Notice this is the same thing you were doing in your progress() function
        for i in range(1, 101):
            #Emit the signal so it can be received on the UI side.
            self.updateProgress.emit(i)
            time.sleep(0.1)

所以現在你有了一個工人階級，是時候利用它了。 您需要在Ui_Dialog類中創建一個新函數來處理發出的信號。

def setProgress(self, progress):
    self.progressBar.setValue(progress)

當你在那里時，你可以刪除progress()函數。

在retranslateUi()您將需要更新按鈕事件處理程序

self.pushButton.clicked.connect(self.progress)

至

self.pushButton.clicked.connect(self.worker.start)

最后，在你的setupUI()函數中，你需要創建一個worker類的實例，並將它的信號連接到你的setProgress()函數。

在這之前：

self.retranslateUi(Dialog)

添加這個：

self.worker = Worker()
self.worker.updateProgress.connect(self.setProgress)

---

這是最終的代碼：

from PySide import QtCore, QtGui
import time


class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(400, 133)
        self.progressBar = QtGui.QProgressBar(Dialog)
        self.progressBar.setGeometry(QtCore.QRect(20, 10, 361, 23))
        self.progressBar.setProperty("value", 24)
        self.progressBar.setObjectName("progressBar")
        self.pushButton = QtGui.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(20, 40, 361, 61))
        self.pushButton.setObjectName("pushButton")

        self.worker = Worker()
        self.worker.updateProgress.connect(self.setProgress)

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

        self.progressBar.minimum = 1
        self.progressBar.maximum = 100

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(QtGui.QApplication.translate("Dialog", "Dialog", None, QtGui.QApplication.UnicodeUTF8))
        self.pushButton.setText(QtGui.QApplication.translate("Dialog", "PushButton", None, QtGui.QApplication.UnicodeUTF8))
        self.progressBar.setValue(0)
        self.pushButton.clicked.connect(self.worker.start)

    def setProgress(self, progress):
        self.progressBar.setValue(progress)

#Inherit from QThread
class Worker(QtCore.QThread):

    #This is the signal that will be emitted during the processing.
    #By including int as an argument, it lets the signal know to expect
    #an integer argument when emitting.
    updateProgress = QtCore.Signal(int)

    #You can do any extra things in this init you need, but for this example
    #nothing else needs to be done expect call the super's init
    def __init__(self):
        QtCore.QThread.__init__(self)

    #A QThread is run by calling it's start() function, which calls this run()
    #function in it's own "thread". 
    def run(self):
        #Notice this is the same thing you were doing in your progress() function
        for i in range(1, 101):
            #Emit the signal so it can be received on the UI side.
            self.updateProgress.emit(i)
            time.sleep(0.1)

if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    sys.exit(app.exec_())

---

QThreads有一些自動發出的內置信號。 您可以在文檔中看到它們以及有關QThreads的更多信息

Answer 2

認為你總是需要使用多線程來做這樣的事情是錯誤的。

如果您可以將長時間運行的任務分解為一系列小步驟，那么您需要做的就是確保經常處理任何待處理事件，以便GUI保持響應。 這可以安全地從主界面線程內通過完成processEvents ，就像這樣：

    for i in range(1, 101):
        self.progressBar.setValue(i)
        QtGui.qApp.processEvents()
        time.sleep(0.1)

鑒於它的簡單性，在選擇更多重量級解決方案（如多線程或多處理）之前，至少考慮這種技術總是值得的。