PyQt5 signal and slot
PyQt5 的 signal 与 slot 有所改变，例如，先定义一个 ZeroSignal 类：
class ZeroSignal(QObject): atzero = pyqtSignal(int)
使用时，一是绑定 slot 如下：
self.zerosig = ZeroSignal()
self.zerosig.atzero[int].connect(self.countZero)
然后是找个机会发动之：
def checkZero(self): if self.value() == 0: self.zerosig.atzero.emit(self.value())
大约如此，完整代码如下：
import os import sys from PyQt5.QtCore import * from PyQt5.QtGui import * from PyQt5.QtWidgets import * class ZeroSignal(QObject): atzero = pyqtSignal(int) class ZeroSpinBox(QSpinBox): def __init__(self, parent=None): super(ZeroSpinBox, self).__init__(parent) self.zeros = 0 self.valueChanged[int].connect(self.checkZero) self.zerosig = ZeroSignal() self.zerosig.atzero[int].connect(self.countZero) def countZero(self, v): if v == 0: self.zeros += 1 print(self.zeros) def checkZero(self): if self.value() == 0: self.zerosig.atzero.emit(self.value()) class Form(QDialog): def __init__(self, parent=None): super(Form, self).__init__(parent) dial = QDial() dial.setNotchesVisible(True) spin = ZeroSpinBox() layout = QHBoxLayout() layout.addWidget(dial) layout.addWidget(spin) self.setLayout(layout) dial.valueChanged.connect(spin.setValue) spin.valueChanged.connect(dial.setValue) spin.valueChanged.connect(self.emitZero) self.setWindowTitle("Sinal and Solt") self.zerobox = spin self.zerobox.zerosig.atzero[int].connect(self.annouce) def emitZero(self, v): if v == 0: self.zerobox.zerosig.atzero.emit(self.zerobox.zeros) def annouce(self, v): print("zero count: %d" % v) # print two times because add ZeroSpinBox emit once def run(): app = QApplication(sys.argv) form = Form() form.show() app.exec_() if __name__ == '__main__': run()
关于对话框的代码如下，尤其 NumberLiveDialog 值得推荐：
import sys,math,random,string from PyQt5.QtCore import * from PyQt5.QtGui import * from PyQt5.QtWidgets import * class NumberDialog(QDialog): def __init__(self, format, parent=None): super(NumberDialog, self).__init__(parent) thousandsLabel = QLabel("&Thousands separator:") self.thousandsEdit = QLineEdit(format["thousandsseparator"]) thousandsLabel.setBuddy(self.thousandsEdit) decimalMarkerLabel = QLabel("Decimal $marker:") self.decimalMarkerEdit = QLineEdit(format["decimalmarker"]) decimalMarkerLabel.setBuddy(self.decimalMarkerEdit) decimalPlacesLabel = QLabel("&Decimal places:") self.decimalPlacesSpinBox = QSpinBox() decimalPlacesLabel.setBuddy(self.decimalPlacesSpinBox) self.decimalPlacesSpinBox.setRange(0, 6) self.decimalPlacesSpinBox.setValue(format["decimalplaces"]) self.redNegativesCheckBox = QCheckBox("&Red negative numbers") self.redNegativesCheckBox.setChecked(format["rednegatives"]) buttonBox = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel) self.format = format.copy() grid = QGridLayout() grid.addWidget(thousandsLabel, 0, 0) grid.addWidget(self.thousandsEdit, 0, 1) grid.addWidget(decimalMarkerLabel, 1, 0) grid.addWidget(self.decimalMarkerEdit, 1, 1) grid.addWidget(decimalPlacesLabel, 2, 0) grid.addWidget(self.decimalPlacesSpinBox, 2, 1) grid.addWidget(self.redNegativesCheckBox, 3, 0, 1, 2) grid.addWidget(buttonBox, 4, 0, 1, 2) self.setLayout(grid) buttonBox.accepted.connect(self.accept) buttonBox.rejected.connect(self.reject) self.setWindowTitle("Number format") def accept(self): class ThousandsError(Exception): pass class DecimalError(Exception): pass Punctuation = frozenset(" ,;:.") thousands = str(self.thousandsEdit.text()) decimal = str(self.decimalMarkerEdit.text()) try: if len(decimal) == 0: raise DecimalError("The decimal marker may not be empty.") if len(thousands) > 1: raise ThousandsError("The thousands separator may only be empty or one charactor.") if len(decimal) > 1: raise DecimalError("The decimal marker must be one character.") if thousands == decimal: raise ThousandsError("The thousands separator and decimal marker must be different.") if thousands and thousands not in Punctuation: raise ThousandsError("The thousands separator must be in Punctuation.") if decimal and decimal not in Punctuation: raise DecimalError("The decimal marker must be a punctuation symbol.") except ThousandsError as e: QMessageBox.warning(self, "Thousands separator error:", str(e)) self.thousandsEdit.selectAll() self.thousandsEdit.setFocus() return except DecimalError as e: QMessageBox.warning(self, "Decimal marker error:", str(e)) self.decimalMarkerEdit.selectAll() self.decimalMarkerEdit.setFocus() return self.format["thousandsseparator"] = thousands self.format["decimalmarker"] = decimal self.format["decimalplaces"] = self.decimalPlacesSpinBox.value() self.format["rednegatives"] = self.redNegativesCheckBox.isChecked() QDialog.accept(self) def numberFormat(self): return self.format class NumberModelessDialog(QDialog): changed = pyqtSignal() def __init__(self, format, parent=None): super(NumberModelessDialog, self).__init__(parent) self.setAttribute(Qt.WA_DeleteOnClose) punctuationRe = QRegularExpression(r"[ ,;:.]") thousandsLabel = QLabel("&Thousands separator:") self.thousandsEdit = QLineEdit(format["thousandsseparator"]) thousandsLabel.setBuddy(self.thousandsEdit) self.thousandsEdit.setMaxLength(1) self.thousandsEdit.setValidator(QRegularExpressionValidator(punctuationRe, self)) decimalMarkerLabel = QLabel("Decimal $marker:") self.decimalMarkerEdit = QLineEdit(format["decimalmarker"]) decimalMarkerLabel.setBuddy(self.decimalMarkerEdit) self.decimalMarkerEdit.setMaxLength(1) self.decimalMarkerEdit.setValidator(QRegularExpressionValidator(punctuationRe, self)) decimalPlacesLabel = QLabel("&Decimal places:") self.decimalPlacesSpinBox = QSpinBox() decimalPlacesLabel.setBuddy(self.decimalPlacesSpinBox) self.decimalPlacesSpinBox.setRange(0, 6) self.decimalPlacesSpinBox.setValue(format["decimalplaces"]) self.redNegativesCheckBox = QCheckBox("&Red negative numbers") self.redNegativesCheckBox.setChecked(format["rednegatives"]) buttonBox = QDialogButtonBox(QDialogButtonBox.Apply | QDialogButtonBox.Close) self.format = format grid = QGridLayout() grid.addWidget(thousandsLabel, 0, 0) grid.addWidget(self.thousandsEdit, 0, 1) grid.addWidget(decimalMarkerLabel, 1, 0) grid.addWidget(self.decimalMarkerEdit, 1, 1) grid.addWidget(decimalPlacesLabel, 2, 0) grid.addWidget(self.decimalPlacesSpinBox, 2, 1) grid.addWidget(self.redNegativesCheckBox, 3, 0, 1, 2) grid.addWidget(buttonBox, 4, 0, 1, 2) self.setLayout(grid) buttonBox.button(QDialogButtonBox.Apply).clicked.connect(self.apply) buttonBox.rejected.connect(self.reject) self.setWindowTitle("Number format") def apply(self): thousands = str(self.thousandsEdit.text()) decimal = str(self.decimalMarkerEdit.text()) if thousands == decimal: QMessageBox.warning(self, "Thousands separator error") self.thousandsEdit.selectAll() self.thousandsEdit.setFocus() return if len(decimal) == 0: QMessageBox.warning(self, "Decimal marker cannot is empty.") self.decimalMarkerEdit.selectAll() self.decimalMarkerEdit.setFocus() return self.format["thousandsseparator"] = thousands self.format["decimalmarker"] = decimal self.format["decimalplaces"] = self.decimalPlacesSpinBox.value() self.format["rednegatives"] = self.redNegativesCheckBox.isChecked() self.changed.emit() class NumberLiveDialog(QDialog): changed = pyqtSignal() def __init__(self, format, callback, parent=None): super(NumberLiveDialog, self).__init__(parent) self.format = format self.callback = callback self.setAttribute(Qt.WA_DeleteOnClose) punctuationRe = QRegularExpression(r"[ ,;:.]") thousandsLabel = QLabel("&Thousands separator:") self.thousandsEdit = QLineEdit(format["thousandsseparator"]) thousandsLabel.setBuddy(self.thousandsEdit) self.thousandsEdit.setMaxLength(1) self.thousandsEdit.setValidator(QRegularExpressionValidator(punctuationRe, self)) decimalMarkerLabel = QLabel("Decimal $marker:") self.decimalMarkerEdit = QLineEdit(format["decimalmarker"]) decimalMarkerLabel.setBuddy(self.decimalMarkerEdit) self.decimalMarkerEdit.setMaxLength(1) self.decimalMarkerEdit.setValidator(QRegularExpressionValidator(punctuationRe, self)) decimalPlacesLabel = QLabel("&Decimal places:") self.decimalPlacesSpinBox = QSpinBox() decimalPlacesLabel.setBuddy(self.decimalPlacesSpinBox) self.decimalPlacesSpinBox.setRange(0, 6) self.decimalPlacesSpinBox.setValue(format["decimalplaces"]) self.redNegativesCheckBox = QCheckBox("&Red negative numbers") self.redNegativesCheckBox.setChecked(format["rednegatives"]) grid = QGridLayout() grid.addWidget(thousandsLabel, 0, 0) grid.addWidget(self.thousandsEdit, 0, 1) grid.addWidget(decimalMarkerLabel, 1, 0) grid.addWidget(self.decimalMarkerEdit, 1, 1) grid.addWidget(decimalPlacesLabel, 2, 0) grid.addWidget(self.decimalPlacesSpinBox, 2, 1) grid.addWidget(self.redNegativesCheckBox, 3, 0, 1, 2) self.setLayout(grid) self.thousandsEdit.textEdited.connect(self.checkAndFix) self.decimalMarkerEdit.textEdited.connect(self.checkAndFix) self.decimalPlacesSpinBox.valueChanged.connect(self.apply) self.redNegativesCheckBox.toggled.connect(self.apply) self.setWindowTitle("Number format") def checkAndFix(self): thousands = self.thousandsEdit.text() decimal = self.decimalMarkerEdit.text() if thousands == decimal: self.thousandsEdit.clear() self.thousandsEdit.setFocus() if len(decimal) == 0: self.decimalMarkerEdit.setText(".") self.decimalMarkerEdit.selectAll() self.decimalMarkerEdit.setFocus() self.apply() def apply(self): thousands = self.thousandsEdit.text() decimal = self.decimalMarkerEdit.text() self.format["thousandsseparator"] = thousands self.format["decimalmarker"] = decimal self.format["decimalplaces"] = self.decimalPlacesSpinBox.value() self.format["rednegatives"] = self.redNegativesCheckBox.isChecked() self.callback() class Form(QDialog): X_MAX = 26 Y_MAX = 60 def __init__(self, parent=None): super(Form, self).__init__(parent) self.numberDlg = None self.format = { "thousandsseparator":",", "decimalmarker":".", "decimalplaces":2, "rednegatives": False } self.numbers = {} for x in range(self.X_MAX): for y in range(self.Y_MAX): self.numbers[(x,y)] = 10000 * random.random() - 5000 self.table = QTableWidget() modalButton = QPushButton("Set numbe format...(&Modal)") modelessButton = QPushButton("Set number format...(M&odeless)") liveButton = QPushButton("Set number format...(&Live)") buttonLayout = QHBoxLayout() buttonLayout.addStretch() buttonLayout.addWidget(modalButton) buttonLayout.addWidget(modelessButton) buttonLayout.addWidget(liveButton) layout = QVBoxLayout() layout.addWidget(self.table) layout.addLayout(buttonLayout) self.setLayout(layout) modalButton.clicked.connect(self.setNumberFormatByModal) modelessButton.clicked.connect(self.setNumberFormatByModeless) liveButton.clicked.connect(self.setNumberFormatByLive) self.setWindowTitle("Set Number Format") self.refreshTable() def refreshTable(self): self.table.clear() self.table.setRowCount(self.Y_MAX) self.table.setColumnCount(self.X_MAX) self.table.setHorizontalHeaderLabels(list(string.ascii_uppercase)) for x in range(self.X_MAX): for y in range(self.Y_MAX): fraction, whole = math.modf(self.numbers[(x,y)]) sign = "-" if whole < 0 else "" whole = "{0}".format(int(math.floor(abs(whole)))) digits = [] for i, digit in enumerate(reversed(whole)): if i and i % 3 == 0: digits.insert(0, self.format["thousandsseparator"]) digits.insert(0, digit) if self.format["decimalplaces"]: fraction = "{0:.7f}".format(abs(fraction)) fraction = self.format["decimalmarker"] + fraction[2:self.format["decimalplaces"]+2] else: fraction = "" text = "{0}{1}{2}".format(sign, "".join(digits), fraction) item = QTableWidgetItem(text) item.setTextAlignment(Qt.AlignRight | Qt.AlignVCenter) if sign and self.format["rednegatives"]: item.setBackground(Qt.red) self.table.setItem(y, x, item) def setNumberFormatByModal(self): dlg = NumberDialog(self.format, self) if dlg.exec_(): self.format = dlg.numberFormat() self.refreshTable() def setNumberFormatByModeless(self): dlg = NumberModelessDialog(self.format, self) dlg.show() dlg.changed.connect(self.refreshTable) def setNumberFormatByLive(self): if self.numberDlg is None: self.numberDlg = NumberLiveDialog(self.format, self.refreshTable, self) self.numberDlg.show() self.numberDlg.raise_() self.numberDlg.activateWindow() if __name__ == "__main__": app = QApplication(sys.argv) form = Form() form.show() app.exec_()
关于主窗口 (fileload function need add a bool parameter for recentfiles) 的代码：imagechanger
运行效果图如下：
《Python GUI Qt 快速开放指南》部分例子： PyQt5-Code
