I am new to both pyqt and python so I'm sure that my question would seem stupid, so thank you for reading and answer it. It is really helpful.
Here is my source code
# -*- coding: utf-8 -*-
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import sys
QTextCodec.setCodecForTr(QTextCodec.codecForName("utf8"))
class Prog(QDialog):
def __init__(self,parent=None):
super(Prog,self).__init__(parent)
self.start_P()
def start_P(self):
progressDialog=QProgressDialog(self)
progressDialog.setWindowModality(Qt.WindowModal)
progressDialog.setMinimumDuration(5)
progressDialog.setWindowTitle(self.tr("请等待"))
progressDialog.setLabelText(self.tr("拷贝..."))
progressDialog.setCancelButtonText(self.tr("取消"))
progressDialog.setRange(0,100)
progressDialog.setAutoClose(True)
for i in range(101):
progressDialog.setValue(i)
QThread.msleep(10)
if progressDialog.wasCanceled():
return
self.connect(progressDialog,SIGNAL("closed()"))
def main():
app = QApplication(sys.argv)
pp = Prog()
pp.show()
app.exec_()
if __name__ == '__main__':
main()
There are some Chinese characters, but it's irrelevant. The strange part is when I execute this program I would get a window of progress dialog, that is what I want. But when it is auto closed a pythonw window generated automatically.
I was curious about why this pythonw window was generated and want to know how to avoid it.
That's because you are creating your QProgressDialog as child of a QDialog, checkout the line that says progressDialog=QProgressDialog(self). Checkout how this example works:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
#---------
# IMPORT
#---------
from PyQt4 import QtGui, QtCore
#---------
# MAIN
#---------
class MyThread(QtCore.QThread):
progress = QtCore.pyqtSignal(int)
_stopped = False
def __init__(self, parent=None):
super(MyThread, self).__init__(parent)
def stop(self):
self._stopped = True
def start(self):
self._stopped = False
super(MyThread, self).start()
def run(self):
for progressNumber in range(101):
self.progress.emit(progressNumber)
self.msleep(22)
if self._stopped:
return
class MyWindow(QtGui.QProgressDialog):
def __init__(self, parent=None):
super(MyWindow, self).__init__(parent)
self.threadProgress = MyThread(self)
self.threadProgress.progress.connect(self.setValue)
def stop(self):
self.threadProgress.stop()
def start(self):
self.threadProgress.start()
def hideEvent(self, event):
self.close()
if __name__ == "__main__":
import sys
codec = QtCore.QTextCodec.codecForName("utf8")
QtCore.QTextCodec.setCodecForTr(codec)
app = QtGui.QApplication(sys.argv)
app.setApplicationName('MyWindow')
main = MyWindow()
main.setWindowTitle(main.tr("请等待"))
main.setLabelText(main.tr("拷贝..."))
main.setCancelButtonText(main.tr("取消"))
main.setRange(0,100)
main.canceled.connect(main.stop)
main.show()
main.start()
sys.exit(app.exec_())
Related
I use a pyqt_signal to transmit a sub window, which has a button whose function is to print. I use a thread to transmit this sub window to the main window to show, however the button loses its function. I know that I should put the statement self.sub_window = SubWindow() into the __init__ function in the second class, but how can I achieve the same effect if I still put this statement here.
# -*- coding: utf-8 -*-
from threading import currentThread
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton
import sys
from PyQt5.QtCore import pyqtSignal, QObject, QThread
class SubWindow(QWidget):
def __init__(self):
super(SubWindow, self).__init__()
self.resize(400, 400)
self.button = QPushButton(self)
self.button.setText('push me to print ***')
self.button.move(200, 200)
self.button.clicked.connect(self.print_)
def print_(self):
print('***')
class SignalStore(QThread):
window_signal = pyqtSignal(object)
def __init__(self):
super(SignalStore, self).__init__()
def run(self):
# if i put this statement here, how can i acquire window's print button function
self.sub_window = SubWindow()
self.window_signal.emit(self.sub_window)
class MainWindow(QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.resize(400, 400)
self.button = QPushButton(self)
self.button.setText('push me to get subwindow')
self.button.move(200, 200)
self.button.clicked.connect(self.send_signal)
self.med_signal = SignalStore()
self.med_signal.window_signal.connect(self.get_sub_window)
def send_signal(self):
self.med_signal.start()
def get_sub_window(self, para):
self.sub_window = para
self.sub_window.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())
Don't create or access gui objects inside threads. Read Qt guide.
GUI Thread and Worker Thread
As mentioned, each program has one thread when it is started. This thread is called the "main thread" (also known as the "GUI thread" in Qt applications). The Qt GUI must run in this thread. All widgets and several related classes, for example QPixmap, don't work in secondary threads. A secondary thread is commonly referred to as a "worker thread" because it is used to offload processing work from the main thread.
This is probably what you are looking for:
import time
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton
import sys
from PyQt5.QtCore import pyqtSignal, QThread, pyqtSlot
class SubWindow(QWidget):
def __init__(self, parent=None):
super(SubWindow, self).__init__(parent)
self.resize(400, 400)
self.button = QPushButton(self)
self.button.setText('push me to print ***')
self.button.move(200, 200)
self.button.clicked.connect(self.print_)
#pyqtSlot()
def print_(self):
print('hello from subwindow')
class SignalStore(QThread):
print_func = pyqtSignal(str)
def __init__(self):
super(SignalStore, self).__init__()
def run(self):
time.sleep(1) # fake working...
self.print_func.emit("hello from thread")
class MainWindow(QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.resize(400, 400)
self.subwin = SubWindow()
self.button = QPushButton(self)
self.button.setText('push me to get subwindow')
self.button.move(200, 200)
self.button.clicked.connect(self.send_signal)
self.med_signal = SignalStore()
self.med_signal.print_func.connect(self.print_from_main)
def send_signal(self):
self.subwin.show()
self.med_signal.start()
#pyqtSlot(str)
def print_from_main(self, string: str):
print(string)
self.subwin.print_()
if __name__ == '__main__':
app = QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())
I want to use startup function which should have while loop.
but I run the code my gui doesn't appear until while loop ends.
I tried with self.show() it can make show gui but it doesn't allow to use sys.exit()
import sys
from PyQt5.QtWidgets import QApplication
from PyQt5 import uic
import time
form_class,QMainWindow=uic.loadUiType('youhua.ui')
class MyWindow(QMainWindow,form_class):
def __init__(self):
super().__init__()
self.setupUi(self)
#self.show()
self.myfunc()
def myfunc(self):
k=1
stat=True
while stat:
k=k+1
time.sleep(1)
self.statusMessage.append(str(k))
QApplication.processEvents()
if k>10:
stat=False
#sys.exit()
if __name__=='__main__':
app=QApplication(sys.argv)
myWindow=MyWindow()
myWindow.show()
app.exec_()
If you need to perform an action again, you have several options.
For example, if each iteration takes very little time, without the possibility of blocking the main loop, you can replace the cycle with a timer (QTimer) and call the method each time, which is responsible for obtaining new data and updating the necessary interface elements in accordance with them:
import sys
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5 import uic
from PyQt5.QtCore import QThread, QTimer
import time
#form_class, QMainWindow = uic.loadUiType('youhua.ui')
class MyWindow(QMainWindow): #, form_class):
def __init__(self):
super().__init__()
self.k = 0
centralWidget = QtWidgets.QWidget(self)
self.setCentralWidget(centralWidget)
self.button = QtWidgets.QPushButton('Start', self)
self.button.clicked.connect(self.read_data)
self.label_data = QtWidgets.QLabel(self, alignment=QtCore.Qt.AlignCenter)
self.label_data.setText('Pending')
layout = QtWidgets.QGridLayout(centralWidget)
layout.addWidget(self.label_data)
layout.addWidget(self.button)
self.timer = QtCore.QTimer(self)
self.timer.setInterval(1000)
self.timer.timeout.connect(self.read_data_from_sensor)
#QtCore.pyqtSlot()
def read_data(self):
''' Start / Stop reading at the touch of a button '''
if not self.timer.isActive():
self.timer.start()
self.button.setText("Stop")
else:
self.timer.stop()
self.button.setText("Start")
self.label_data.setText("Pending")
#QtCore.pyqtSlot()
def read_data_from_sensor(self):
dt = time.strftime("%Y-%m-%d %H:%M:%S")
self.label_data.setText(dt)
self.label_data.adjustSize()
self.k += 1
self.statusBar().showMessage('{} item(s)'.format(self.k))
if self.k > 10:
self.timer.stop()
self.button.setText("Start")
self.label_data.setText("Pending")
self.k = 0
if __name__=='__main__':
app = QApplication(sys.argv)
myWindow = MyWindow()
myWindow.show()
app.exec_()
What you wrote may also work, but this is not very good. You can compare.
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5 import uic
from PyQt5.QtCore import QThread
#import time
#form_class, QMainWindow = uic.loadUiType('youhua.ui')
class MyWindow(QMainWindow): #, form_class):
def __init__(self):
super().__init__()
# self.setupUi(self)
self.show()
self.myfunc()
def myfunc(self):
k = 0
stat = True
while stat:
k += 1
# time.sleep(1)
# self.statusMessage.append(str(k))
self.statusBar().showMessage('{} item(s)'.format(k))
QThread.msleep(1000)
QApplication.processEvents()
if k>10:
stat=False
#sys.exit()
if __name__=='__main__':
app = QApplication(sys.argv)
myWindow = MyWindow()
# myWindow.show()
app.exec_()
In your loop you are sleeping for 10 second, since you are creating a while loop on the main thread, the GUI wont show until the loop is done because it would be blocking the main thread. You can test this by removing time.sleep(1).
Without changing your code much, try this:
import sys,threading, time
from PyQt5.QtWidgets import QApplication
from PyQt5 import uic
form_class,QMainWindow=uic.loadUiType('youhua.ui')
class MyWindow(QMainWindow,form_class):
def __init__(self):
super().__init__()
self.setupUi(self)
#self.show()
t = threading.Thread(target=self.myfunc)
t.start()
def myfunc(self):
k=1
stat=True
while stat:
k=k+1
time.sleep(1)
self.statusMessage.append(str(k))
QApplication.processEvents()
if k>10:
stat=False
#sys.exit() - if you are trying to close the window here use self.close()
if __name__=='__main__':
app=QApplication(sys.argv)
myWindow=MyWindow()
myWindow.show()
sys.exit(app.exec_())
First of all, similar questions have been answered before, yet I need some help with this one.
I have a window which contains one button (Class First) and I want on pressed, a second blank window to be appeared (Class Second).
I fiddled with the code copied from this question: PyQT on click open new window, and I wrote this code:
# -*- coding: utf-8 -*-
from PyQt4 import QtGui, QtCore
import sys
import design1, design2
class Second(QtGui.QMainWindow, design2.Ui_MainWindow):
def __init__(self, parent=None):
super(Second, self).__init__(parent)
self.setupUi(self)
class First(QtGui.QMainWindow, design1.Ui_MainWindow):
def __init__(self, parent=None):
super(First, self).__init__(parent)
self.setupUi(self)
self.pushButton.clicked.connect(self.on_pushButton_clicked)
self.dialog = Second(self)
def on_pushButton_clicked(self):
self.dialog.exec_()
def main():
app = QtGui.QApplication(sys.argv)
main = First()
main.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
but on_pressed, this error message appears:
AttributeError: 'Second' object has no attribute 'exec_'
(design1 and design2 have been derived from the Qt designer.)
Any thought would be appreciated.
Here I'm using the show method.
Here is a working example (derived from yours):
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from PyQt4 import QtGui, QtCore
import sys
class Second(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Second, self).__init__(parent)
class First(QtGui.QMainWindow):
def __init__(self, parent=None):
super(First, self).__init__(parent)
self.pushButton = QtGui.QPushButton("click me")
self.setCentralWidget(self.pushButton)
self.pushButton.clicked.connect(self.on_pushButton_clicked)
self.dialog = Second(self)
def on_pushButton_clicked(self):
self.dialog.show()
def main():
app = QtGui.QApplication(sys.argv)
main = First()
main.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
If you need a new window every time you click the button, you can change the code that the dialog is created inside the on_pushButton_clicked method, like so:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from PyQt4 import QtGui, QtCore
import sys
class Second(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Second, self).__init__(parent)
class First(QtGui.QMainWindow):
def __init__(self, parent=None):
super(First, self).__init__(parent)
self.pushButton = QtGui.QPushButton("click me")
self.setCentralWidget(self.pushButton)
self.pushButton.clicked.connect(self.on_pushButton_clicked)
self.dialogs = list()
def on_pushButton_clicked(self):
dialog = Second(self)
self.dialogs.append(dialog)
dialog.show()
def main():
app = QtGui.QApplication(sys.argv)
main = First()
main.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
import sys
from PyQt4 import QtCore, QtGui, uic
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import time
import datetime
import re
import random
import csv
from CropClass import *
from Wheat_class import *
from Potato_class import *
win1 = uic.loadUiType("MenuScreen.ui")[0]
win2 = uic.loadUiType("WheatScreen.ui")[0]
win3 = uic.loadUiType("PotatoScreen.ui") [0]
class MenuScreen(QtGui.QMainWindow, win1):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
self.BtnCreateSimulation.clicked.connect(self.changeSimulation)
def changeSimulation(self):
if self.RdoWheat.isChecked() ==True:
print("Wheat is picked")
new_crop=Wheat()
self.wheatSimulation()
elif self.RdoPotato.isChecked() == True:
print("Potato is picked")
new_crop = Potato()
self.PotatoSimulation()
def wheatSimulation(self):
print("Hello")
self.hide()
WheatWindow.show()
def PotatoSimulation(self):
self.hide()
PotatoWindow.show()
class PotatoScreen(QtGui.QMainWindow, win3):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
self.BtnBacktoMenu.clicked.connect(self.BackToMain)
def BackToMain(self):
self.hide()
MenuWindow.show()
class WheatScreen(QtGui.QMainWindow, win2):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
new_crop = Wheat()
self.BtnBacktoMenu.clicked.connect(self.BackToMain)
self.BtnManual.clicked.connect(self.ManualCalculate)
def BackToMain(self):
self.hide()
MenuWindow.show()
def ManualCalculate(self):
water = self.spBoxWater.value()
light= self.spBoxLight.value()
print("water", water, "light", light)
def main():
app = QtGui.QApplication(sys.argv)
WheatWindow = WheatScreen(None)
PotatoWindow = PotatoScreen(None)
MenuWindow = MenuScreen(None)
MenuWindow.show()
app.exec_()
if __name__ == "__main__":
main()
I have created a program in Python which simulates the growth rates of crops. The user is able to chose between the crop is wheat or potatoes I am trying to create a GUI using PYQT. The problem I am having is that when I try and load the program the program is not recognizing the other screen layouts. The main function should be setting up the screen layouts
Can't work out how to embed a window in a main window using classes:
#!/usr/bin/python3
# -*- coding: utf-8 -*-
"""
Qt4 tutorial using classes
This example will be built
on over time.
"""
import sys
from PyQt4 import QtGui, QtCore
class Form(QtGui.QWidget):
def __init__(self, MainWindow):
super(Form, self).__init__()
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__()
self.setGeometry(50, 50, 1600, 900)
new_window = Form(self)
self.show()
def main():
app = QtGui.QApplication(sys.argv)
main_window = MainWindow()
sys.exit(app.exec_())
if __name__ == "__main__":
main()
This is supposed to be the single most basic bit of code using classes. How do I get the second window to show please.
As ekhumoro already pointed out, your widget needs to be a child of your mainWindow. However, I do not think that you need to call show for the widget, since it anyways gets called as soon as its parent (MainWindow) calls show. As mata pointed out correctly, the proper way to add a Widget to a MainWindow instance is to use setCentralWidget. Here is a working example for clarification:
import sys
from PyQt4 import QtGui, QtCore
class Form(QtGui.QWidget):
def __init__(self, parent):
super(Form, self).__init__(parent)
self.lbl = QtGui.QLabel("Test", self)
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__()
self.setGeometry(50, 50, 1600, 900)
new_window = Form(self)
self.setCentralWidget(new_window)
self.show()
def main():
app = QtGui.QApplication(sys.argv)
main_window = MainWindow()
sys.exit(app.exec_())
if __name__ == "__main__":
main()