我如何 change/update 标签

Question

我正在尝试使用 pyqt5 构建一个简单的互联网速度测试应用程序 我是初学者，正在尝试构建小型应用程序来学习 GUI 基础知识所以这里是每当我尝试从我的线程函数更改标签文本时的代码，它说 self 没有名为 label_7 的成员。忽略打印语句，我只是用它们来调试

def Update_values(self,MainWindow):
        _translate = QtCore.QCoreApplication.translate
        self.label_7.setText(_translate("MainWindow", "Download Speed   : " + str(down)))

在代码的上半部分我得到了错误提前谢谢你

from PyQt5 import QtCore, QtGui, QtWidgets
import speedtest as st
speed_test = st.Speedtest()
download = speed_test.download()
val = 0
val1 = 0
val3 = 0
down = 0 
up = 0
pin = 0

class Ui_MainWindow(object):

    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(331, 307)
        font = QtGui.QFont()
        font.setFamily("Lucida Sans Unicode")
        MainWindow.setFont(font)
        MainWindow.setCursor(QtGui.QCursor(QtCore.Qt.PointingHandCursor))
        MainWindow.setMouseTracking(False)
        MainWindow.setTabletTracking(False)
        MainWindow.setToolButtonStyle(QtCore.Qt.ToolButtonIconOnly)
        MainWindow.setDocumentMode(False)
        MainWindow.setTabShape(QtWidgets.QTabWidget.Triangular)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.label = QtWidgets.QLabel(self.centralwidget)
        font = QtGui.QFont()
        font.setFamily("Comic Sans MS")
        font.setPointSize(16)
        self.label.setFont(font)
        self.label.setObjectName("label")
        self.gridLayout.addWidget(self.label, 0, 0, 1, 3)
        self.line_2 = QtWidgets.QFrame(self.centralwidget)
        self.line_2.setFrameShape(QtWidgets.QFrame.HLine)
        self.line_2.setFrameShadow(QtWidgets.QFrame.Sunken)
        self.line_2.setObjectName("line_2")
        self.gridLayout.addWidget(self.line_2, 1, 0, 1, 3)
        self.label_2 = QtWidgets.QLabel(self.centralwidget)
        self.label_2.setObjectName("label_2")
        self.gridLayout.addWidget(self.label_2, 2, 0, 1, 2)
        self.label_4 = QtWidgets.QLabel(self.centralwidget)
        self.label_4.setFrameShape(QtWidgets.QFrame.NoFrame)
        self.label_4.setObjectName("label_4")
        self.gridLayout.addWidget(self.label_4, 3, 0, 1, 2)
        self.label_3 = QtWidgets.QLabel(self.centralwidget)
        self.label_3.setObjectName("label_3")
        self.gridLayout.addWidget(self.label_3, 4, 0, 1, 2)
        self.label_7 = QtWidgets.QLabel(self.centralwidget)
        self.label_7.setObjectName("label_7")
        self.gridLayout.addWidget(self.label_7, 5, 0, 1, 2)
        self.label_8 = QtWidgets.QLabel(self.centralwidget)
        self.label_8.setObjectName("label_8")
        self.gridLayout.addWidget(self.label_8, 6, 0, 1, 1)
        self.progressBar = QtWidgets.QProgressBar(self.centralwidget)
        self.progressBar.setProperty("value", 24)
        self.progressBar.setTextVisible(False)
        self.progressBar.setObjectName("progressBar")
        self.gridLayout.addWidget(self.progressBar, 7, 0, 1, 3)
        self.check1 = QtWidgets.QCheckBox(self.centralwidget)
        self.check1.setObjectName("check1")
        self.check1.stateChanged.connect(self.check_1)
        self.gridLayout.addWidget(self.check1, 8, 0, 1, 1)
        self.check2 = QtWidgets.QCheckBox(self.centralwidget)
        self.check2.setObjectName("check2")
        self.check2.stateChanged.connect(self.check_2)
        self.gridLayout.addWidget(self.check2, 8, 1, 1, 1)
        self.check3 = QtWidgets.QCheckBox(self.centralwidget)
        self.check3.setObjectName("check3")
        self.check3.stateChanged.connect(self.check_3)
        self.gridLayout.addWidget(self.check3, 8, 2, 1, 1)
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setObjectName("pushButton")
        self.pushButton.clicked.connect(self.start_test)
        self.gridLayout.addWidget(self.pushButton, 9, 0, 1, 3)
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 331, 22))
        self.menubar.setObjectName("menubar")
        self.menuFile = QtWidgets.QMenu(self.menubar)
        self.menuFile.setObjectName("menuFile")
        self.menuAbout = QtWidgets.QMenu(self.menubar)
        self.menuAbout.setObjectName("menuAbout")
        MainWindow.setMenuBar(self.menubar)
        self.actionSave_Results = QtWidgets.QAction(MainWindow)
        self.actionSave_Results.setCheckable(False)
        self.actionSave_Results.setChecked(False)
        self.actionSave_Results.setObjectName("actionSave_Results")
        self.actionChange_Save_Directory = QtWidgets.QAction(MainWindow)
        self.actionChange_Save_Directory.setObjectName("actionChange_Save_Directory")
        self.actionDeveloper = QtWidgets.QAction(MainWindow)
        self.actionDeveloper.setObjectName("actionDeveloper")
        self.menuFile.addAction(self.actionSave_Results)
        self.menuFile.addAction(self.actionChange_Save_Directory)
        self.menuAbout.addAction(self.actionDeveloper)
        self.menubar.addAction(self.menuFile.menuAction())
        self.menubar.addAction(self.menuAbout.menuAction())
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "Internet Speed Test"))
        self.label.setText(_translate("MainWindow", "Internet Speed Test By FATE"))
        self.label_2.setText(_translate("MainWindow", "Status : Connected"))
        self.label_4.setText(_translate("MainWindow", "Ping   :   --"))
        self.label_3.setText(_translate("MainWindow", "Upload Speed   :   --"))
        self.label_7.setText(_translate("MainWindow", "Download Speed   :   --"))
        self.label_8.setText(_translate("MainWindow", "Progress :"))
        self.check1.setText(_translate("MainWindow", "Download"))
        self.check2.setText(_translate("MainWindow", "Upload"))
        self.check3.setText(_translate("MainWindow", "Ping"))
        self.pushButton.setText(_translate("MainWindow", "Start"))
        self.menuFile.setTitle(_translate("MainWindow", "File"))
        self.menuAbout.setTitle(_translate("MainWindow", "About"))
        self.actionSave_Results.setText(_translate("MainWindow", "Save Results"))
        self.actionChange_Save_Directory.setText(_translate("MainWindow", "Change Save Directory"))
        self.actionDeveloper.setText(_translate("MainWindow", "Developer"))
        self.Update_values(MainWindow)

    def Update_values(self,MainWindow):
        _translate = QtCore.QCoreApplication.translate
        self.label_7.setText(_translate("MainWindow", "Download Speed   : " + str(down)))
        # self.label_7.setText(_translate("MainWindow", "Download Speed   :   10"))  
        print(down)
        print(up)
        print(pin)

    def check_1(self, state):
        global val
        print(val)
        if state != self.check1.isChecked():
            val += 1
            print("YESH "+ str(val))
        else:
            val -= 1
            print("NO" + str(val)) 

    def check_2(self, state):
        global val1
        print(val1)
        if state != self.check1.isChecked():
            val1 += 1
            print("YESH "+ str(val1))
        else:
            val1 -= 1
            print("NO" + str(val1)) 
    def check_3(self, state):
        global val3
        print(val3)
        if state != self.check1.isChecked():
            val3 += 1
            print("YESH "+ str(val3))
        else:
            val3 -= 1
            print("NO" + str(val3)) 

    def start_test(self):
        self.threadclass = Thread()
        self.threadclass.start()

class Thread(QtCore.QThread,Ui_MainWindow):
    def __init__(self,parent = None):
        super(Thread, self).__init__(parent)
    def run(self):
        if val == 1:
            download = speed_test.download()
            download_mbs = round(download / (10**6), 2)
            global down
            down = download_mbs
            self.Update_values(Ui_MainWindow)
        if val1 == 1:
            upload = speed_test.upload()
            upload_mbs = round(upload / (10**6), 2)
            global up
            up = upload_mbs
        if val3 == 1:
            ping = speed_test.results.ping
            global pin
            pin = ping
        print("DONE")
if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Answer 1

_{首先，你不应该修改Qt Designer生成的代码，所以在我的下一个解决方案中你必须重新生成pyuic生成的.py并调用它gui.py：python -m pyuic5 your_ui.ui -o gui.py.}

您遇到的另一个错误是您不应从另一个线程更新 GUI，也不应使用全局变量，因为它们容易产生静默错误，而应使用如下所示的信号：

from enum import Flag, auto
import threading

from PyQt5 import QtCore, QtGui, QtWidgets

import speedtest

from gui import Ui_MainWindow


class Task(Flag):
    NONE = auto()
    DOWNLOAD = auto()
    UPLOAD = auto()
    PING = auto()


class SpeedtestWrapper(QtCore.QObject):
    started = QtCore.pyqtSignal()
    finished = QtCore.pyqtSignal()

    downloaded = QtCore.pyqtSignal(float)
    uploaded = QtCore.pyqtSignal(float)
    pinged = QtCore.pyqtSignal(float)

    def start(self, flag):
        threading.Thread(target=self._execute, args=(flag,), daemon=True).start()

    def _execute(self, flag):
        self.started.emit()
        speed_test = speedtest.Speedtest()
        if flag & Task.DOWNLOAD:
            download = speed_test.download()
            download_mbs = round(download / (10 ** 6), 2)
            self.downloaded.emit(download_mbs)

        if flag & Task.DOWNLOAD:
            upload = speed_test.upload()
            upload_mbs = round(upload / (10 ** 6), 2)
            self.uploaded.emit(upload_mbs)

        if flag & Task.DOWNLOAD:
            ping = speed_test.results.ping
            self.pinged.emit(ping)

        self.finished.emit()


class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setupUi(self)

        self._flag = Task.NONE

        self.speed_wrapper = SpeedtestWrapper()
        self.speed_wrapper.started.connect(self.on_started)
        self.speed_wrapper.finished.connect(self.on_finished)
        self.speed_wrapper.downloaded.connect(self.on_downloaded)
        self.speed_wrapper.uploaded.connect(self.on_uploaded)
        self.speed_wrapper.pinged.connect(self.on_pinged)

    @QtCore.pyqtSlot()
    def start_test(self):
        if self._flag != Task.NONE:
            self.speed_wrapper.start(self._flag)

    @QtCore.pyqtSlot(int)
    def check_1(self, state):
        if state:
            self._flag |= Task.DOWNLOAD
        else:
            self._flag &= ~Task.DOWNLOAD

    @QtCore.pyqtSlot(int)
    def check_2(self, state):
        if state:
            self._flag |= Task.UPLOAD
        else:
            self._flag &= ~Task.UPLOAD

    @QtCore.pyqtSlot(int)
    def check_3(self, state):
        if state:
            self._flag |= Task.PING
        else:
            self._flag &= ~Task.PING

    @QtCore.pyqtSlot()
    def on_started(self):
        self.label_7.setText(self.tr("Download Speed: --"))
        self.label_3.setText(self.tr("Upload Speed: --"))
        self.label_4.setText(self.tr("Ping Speed: --"))
        self.pushButton.setEnabled(False)

    @QtCore.pyqtSlot()
    def on_finished(self):
        self.pushButton.setEnabled(True)

    @QtCore.pyqtSlot(float)
    def on_downloaded(self, download):
        self.label_7.setText(self.tr("Download Speed: %f" % download))

    @QtCore.pyqtSlot(float)
    def on_uploaded(self, upload):
        self.label_3.setText(self.tr("Upload Speed: %f" % upload))

    @QtCore.pyqtSlot(float)
    def on_pinged(self, ping):
        self.label_4.setText(self.tr("Ping Speed: %f" % ping))


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

我如何 change/update 标签

How can i change/update label

python

pyqt

pyqt5

qt-designer

qlabel