我正在學(xué)習(xí)PyQT和多線程，我想在這里需要幫助。在我的代碼中，我有Tool一個(gè)class和一個(gè)thread TaskThread。從線程中，我調(diào)用一個(gè)函數(shù)dummy_function，該函數(shù)執(zhí)行進(jìn)度條在GUI中顯示的過程。當(dāng)dummy_function完成后，我想在GUI打印一條消息，通過調(diào)用self.outputText.setText("Hello")。但是，出現(xiàn)以下錯(cuò)誤：AttributeError：'TaskThread'對象沒有屬性'outputText'我嘗試的第一件事是將以下行添加到我的onStart函數(shù)中：...self.myLongTask.output_dt = self.outputText...然后，在中TaskThread，我dummy_function通過以下方式更改調(diào)用：...dummy_function(self, start_datetime_unix, end_datetime_unix, self.output_dt) ...最后，我通過添加以下新參數(shù)來更改我的dummy_function：def dummy_function(self, start_datetime_unix, end_datetime_unix, output_text): # Dummy function, just to simulate a task. It takes parameters just for testing. result = start_datetime_unix * end_datetime_unix # Pre-steps for mapping from one range to other (progress-bar) OldMax = 99999 OldMin = 1 NewMax = 100 NewMin = 1 OldRange = (OldMax - OldMin) NewRange = (NewMax - NewMin) u = 1 for i in range (OldMax): u = i*2 OldValue = i print OldValue NewValue = (((OldValue - OldMin) * NewRange) / OldRange) + NewMin print "NEW VALUE: ", NewValue self.emit(QtCore.SIGNAL('CPU_VALUE'), NewValue) output_text.setText("Hello")現(xiàn)在，到達(dá)終點(diǎn)時(shí)，程序?qū)㈥P(guān)閉，并顯示以下錯(cuò)誤：QObject：無法為處于不同線程中的父級創(chuàng)建子級。（父母是QTextDocument（0xf13a60），父母的線程是QThread（0xc6f180），當(dāng)前線程是TaskThread（0xee0740）為了嘗試該程序，我升級了GUInterface，因此如有必要，您可以嘗試一下。
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TA貢獻(xiàn)1821條經(jīng)驗(yàn) 獲得超5個(gè)贊
您得到的第一個(gè)是由于TaskThread沒有outputText屬性而引起的，并且您的解決方案在某種程度上是正確的，因?yàn)樗鉀Q了第一個(gè)問題，但是還有另一個(gè)問題，Qt禁止從另一個(gè)生成該線程的線程直接更新該GUI。問題 。Qt表示如果您要使用其他線程的信息更新GUI，您必須使用信號或信號QMetaObject，在這種情況下，我將通過創(chuàng)建一個(gè)signal被調(diào)用來解決它textChanged，它將與的setText()方法連接outputText。
另一方面，我看到您使用的是舊的連接樣式：
self.connect(self.myLongTask, QtCore.SIGNAL('CPU_VALUE'), self.onProgress)
盡管不再建議您仍然可以使用該樣式，但最好還是使用新語法。
最后，連接到信號的功能稱為插槽，因此建議使用裝飾器@QtCore.pyqtSlot(...)，此方法可最大程度地減少資源消耗。
import sys
import datetime
import time
from PyQt4 import QtCore, QtGui, uic
from PyQt4.QtCore import *
from PyQt4.QtGui import *
# Link to GUI
qtCreatorFile = "GUInterface.ui"
Ui_MainWindow, QtBaseClass = uic.loadUiType(qtCreatorFile)
def time_converter_to_unix(start_datetime, end_datetime):
# Convert QTimeEdit to UNIX Timestamp (int, msec included), and then to float
start_datetime_unix_int = start_datetime.toMSecsSinceEpoch ()
start_datetime_unix = (float(start_datetime_unix_int) / 1000)
end_datetime_unix_int = end_datetime.toMSecsSinceEpoch ()
end_datetime_unix = (float(end_datetime_unix_int) / 1000)
return start_datetime_unix, end_datetime_unix
def dummy_function(self, start_datetime_unix, end_datetime_unix):
# Dummy function, just to simulate a task. It takes parameters just for testing.
result = start_datetime_unix * end_datetime_unix
# Pre-steps for mapping from one range to other (progress-bar)
OldMax = 99999
OldMin = 1
NewMax = 100
NewMin = 1
OldRange = (OldMax - OldMin)
NewRange = (NewMax - NewMin)
u = 1
for i in range (OldMax):
u = i*2
OldValue = i
print(OldValue)
NewValue = (((OldValue - OldMin) * NewRange) / OldRange) + NewMin
print("NEW VALUE: ", NewValue)
self.cpuValueChanged.emit(NewValue)
self.textChanged.emit("Hello")
class Tool(QtGui.QMainWindow, Ui_MainWindow):
def __init__(self, parent = None):
# Setting-ip UI
QtGui.QMainWindow.__init__(self)
Ui_MainWindow.__init__(self)
self.setupUi(self)
# Button Action
self.runButton.clicked.connect(self.onStart)
# Progress Bar and Label. At the begining, the bar is at 0
self.progressBar.setValue(0)
self.progressBar.setRange(0,100)
self.resultLabel.setText("Waiting...")
####################################
#TEST: Thread for progress bar
self.myLongTask = TaskThread()
self.myLongTask.cpuValueChanged.connect(self.progressBar.setValue)
self.myLongTask.textChanged.connect(self.outputText.setText)
self.myLongTask.taskFinished.connect(self.onFinished)
####################################
@QtCore.pyqtSlot()
def onStart(self):
self.progressBar.reset()
self.resultLabel.setText("In progress...")
print("(onStart)In progress mode executed")
print("(onStart)INITIALIZE THREAD")
self.myLongTask.start()
print("(onStart)THREAD EXECUTED")
self.myLongTask.start_dt = self.startTime.dateTime() # <----
self.myLongTask.end_dt = self.endTime.dateTime() # <----
@QtCore.pyqtSlot()
def onFinished(self):
# Stop the pulsation when the thread has finished
print("(onFinished) executed")
self.progressBar.setRange(0,1)
self.progressBar.setValue(1)
self.resultLabel.setText("Done")
class TaskThread(QtCore.QThread):
cpuValueChanged = QtCore.pyqtSignal(int)
taskFinished = QtCore.pyqtSignal()
textChanged = QtCore.pyqtSignal(str)
def __del__(self):
self.wait()
def run(self):
# First, we read the times from the QDateTime elements in the interface
print("Getting times...")
start_datetime_unix, end_datetime_unix = time_converter_to_unix(self.start_dt, self.end_dt)
# Then, we put these values in my_function
print("Executing function...")
dummy_function(self, start_datetime_unix, end_datetime_unix)
# To finish, we execute onFinished.
print("Finishing thread...")
self.taskFinished.emit()
def main():
app = QtGui.QApplication(sys.argv)
window = Tool()
window.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
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