自学教程：PyQt 如何创建自定义QWidget

|-- main.py|-- res| `-- fish.jpg`-- ui `-- app_widget.py

import sysfrom PyQt5.QtWidgets import QApplicationfrom ui.app_widget import AppQWidgetif __name__ == '__main__': app = QApplication(sys.argv) w = AppQWidget() w.show() sys.exit(app.exec_())

from PyQt5.QtCore import QCoreApplicationfrom PyQt5.QtGui import QIconfrom PyQt5.QtWidgets import QWidget, QPushButton, QDesktopWidget, QMessageBoxclass AppQWidget(QWidget): """ A custom QWidget by Rust Fisher """ def __init__(self):  super().__init__()  self.init_ui() def init_ui(self):  # self.setGeometry(300, 300, 400, 200) # 相当于move和resize  self.resize(300, 200)  self.move_to_center()  self.setWindowTitle('Demo1')  self.setWindowIcon(QIcon('res/fish.jpg'))  btn1 = QPushButton('Quit', self)  btn1.setToolTip('Click to quit')  btn1.resize(btn1.sizeHint())  btn1.move(200, 150)  btn1.clicked.connect(QCoreApplication.instance().quit) # cannot locate function connect def closeEvent(self, event):  reply = QMessageBox.question(self, 'Message',          'Are you sure to quit now?',          QMessageBox.Yes | QMessageBox.No,          QMessageBox.No)  if reply == QMessageBox.Yes:   event.accept()  else:   event.ignore() def move_to_center(self):  qr = self.frameGeometry()  cp = QDesktopWidget().availableGeometry().center() # got center info here  qr.moveCenter(cp)  self.move(qr.topLeft()) # 应用窗口的左上方的点到qr矩形的左上方的点，因此居中显示在我们的屏幕上

 # 同组的控件可以存在同一个list中 self.cb_list = [  self.ma.i2cCB,  self.ma.mipiCB,  self.ma.eepromCB,  self.ma.tem_sensorCB,  self.ma.lensCB,  self.ma.vcmCB,  self.ma.mirrorCB,  self.ma.mirrorCaliCB, ] self.test_count_et_list = [  self.ma.i2cCountEt,  self.ma.mipiCountEt,  self.ma.eepromCountEt,  self.ma.tem_sensorCountEt,  self.ma.lensCountEt,  self.ma.vcmCountEt,  self.ma.mirrorCountEt,  self.ma.mirrorCaliCountEt, ]# 需要操作某组控件时 直接遍历列表def _click_test_item_cb(self): """ Update [choose all checkbox] by all test item state """ choose_all = True for cb in self.cb_list:  choose_all = choose_all & cb.isChecked() self.ma.selecteAllCB.setChecked(choose_all)

>>> QtGui.QWidget()QWidget: Must construct a QApplication before a QPaintDevice

class RustMainWindow(QMainWindow): """ This is the main class """ def _trigger_english(self):  print "Change to English", QApplication.instance()# Change to English <PyQt4.QtGui.QApplication object at 0x02ABE3A0>

if __name__ == '__main__': app = QApplication(sys.argv) # 这里把app交给了MainWindow，MainWindow关闭时是无法正常退出应用的 main_d = RustMainWindow(app) # 不建议这么做 main_d.show() sys.exit(app.exec_())