PyQt：如何在QStackedWidget中切換小部件

Question

我有兩個按鈕（ wgtbtnA和wgtbtnB ）放置在父對象（ objectName ： stackedWidget ）內的兩個不同頁面（分別為page1和page2 ）上。 我的難題是：運行代碼時，箭頭不會在PyQt中顯示。 為什么？ 如何從第1頁切換到第2頁，反之亦然？

這是運行時的圖像，傳達了我的要求：

Qt Designer：

我想保留那些小的后箭頭。

下面是我的代碼：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'stackedWidget.ui'
#
# Created by: PyQt4 UI code generator 4.11.4
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui
import sys
import os


try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(512, 304)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.stackedWidget = QtGui.QStackedWidget(self.centralwidget)
        self.stackedWidget.setGeometry(QtCore.QRect(150, 60, 161, 121))
        self.stackedWidget.setObjectName(_fromUtf8("stackedWidget"))
        self.page = QtGui.QWidget()
        self.page.setObjectName(_fromUtf8("page"))
        self.wgtMainWindow = QtGui.QPushButton(self.page)
        self.wgtMainWindow.setGeometry(QtCore.QRect(50, 50, 75, 23))
        self.wgtMainWindow.setObjectName(_fromUtf8("wgtMainWindow"))
        self.stackedWidget.addWidget(self.page)
        self.page_2 = QtGui.QWidget()
        self.page_2.setObjectName(_fromUtf8("page_2"))
        self.wgtbtnB = QtGui.QPushButton(self.page_2)
        self.wgtbtnB.setGeometry(QtCore.QRect(50, 50, 75, 23))
        self.wgtbtnB.setObjectName(_fromUtf8("wgtbtnB"))
        self.stackedWidget.addWidget(self.page_2)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 512, 21))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        self.stackedWidget.setCurrentIndex(1)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.wgtMainWindow.setText(_translate("MainWindow", "Widget A", None))
        self.wgtbtnB.setText(_translate("MainWindow", "Widget B", None))


class ControlMainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(ControlMainWindow, self).__init__(parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    mySW = ControlMainWindow()
    mySW.show()
    sys.exit(app.exec_())

Answer 1

您可以使用按鈕來更改頁面： {your QPushButton}.clicked.connect(lambda: {your QStackedWidget}.setCurrentIndex({another page}))

例如：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'stackedWidget.ui'
#
# Created by: PyQt4 UI code generator 4.11.4
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui
import sys


try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(512, 304)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.stackedWidget = QtGui.QStackedWidget(self.centralwidget)
        self.stackedWidget.setGeometry(QtCore.QRect(150, 60, 161, 121))
        self.stackedWidget.setObjectName(_fromUtf8("stackedWidget"))
        self.page = QtGui.QWidget()
        self.page.setObjectName(_fromUtf8("page"))
        self.wgtMainWindow = QtGui.QPushButton(self.page)
        self.wgtMainWindow.setGeometry(QtCore.QRect(50, 50, 75, 23))
        self.wgtMainWindow.setObjectName(_fromUtf8("wgtMainWindow"))
        self.stackedWidget.addWidget(self.page)
        self.page_2 = QtGui.QWidget()
        self.page_2.setObjectName(_fromUtf8("page_2"))
        self.wgtbtnB = QtGui.QPushButton(self.page_2)
        self.wgtbtnB.setGeometry(QtCore.QRect(50, 50, 75, 23))
        self.wgtbtnB.setObjectName(_fromUtf8("wgtbtnB"))
        self.stackedWidget.addWidget(self.page_2)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 512, 21))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        self.stackedWidget.setCurrentIndex(1)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.wgtMainWindow.setText(_translate("MainWindow", "Widget A", None))
        self.wgtbtnB.setText(_translate("MainWindow", "Widget B", None))


class ControlMainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(ControlMainWindow, self).__init__(parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)

        self.ui.wgtbtnB.clicked.connect(lambda : self.ui.stackedWidget.setCurrentIndex(0))
        self.ui.wgtMainWindow.clicked.connect(lambda : self.ui.stackedWidget.setCurrentIndex(1))

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    mySW = ControlMainWindow()
    mySW.show()
    sys.exit(app.exec_())

啟動應用程序：

單擊按鈕后：

單擊另一個按鈕后：

Answer 2

您在設計器中看到的兩個箭頭（在下面的消息中）不會保留到您的應用程序中，這是設計器中的功能，因此您可以輕松地在它們之間進行切換

Answer 3

您在ControlMainWindow類中沒有邏輯可在小部件之間進行切換。 （同樣，我也沒有看到用於切換的任何箭頭小部件），您需要在主類中的QTbuttons中添加一個偵聽器，如下所示，以執行邏輯：

yourQTbutton.itemClicked.connect(self.functioWithUIchangingLogic)

Answer 4

要實現從一個屏幕到另一個屏幕的箭頭，您只需要傳播這些箭頭以確保它們出現在每個視圖中即可-現在可以通過代碼輕松完成此操作，而不必說這在設計人員中有多困難。 這是一個示例，它可以執行您想要的操作。

from sys  import exit as sysExit

from PyQt5.QtCore    import *
from PyQt5.QtGui     import *
from PyQt5.QtWidgets import *

class Win1Disply(QFrame):
    def __init__(self, parent):
        QFrame.__init__(self)

        self.setFrameShape(QFrame.StyledPanel)
        self.setLineWidth(0.2)
        # -------
        self.Cntnr = QVBoxLayout()
        self.Cntnr.addWidget(QTextEdit('This is Window 1 with whatever contents you want'))
        self.Win1Btn = QPushButton('>>')
        self.Win1Btn.clicked.connect(parent.RightArrow)
        self.Cntnr.addWidget(self.Win1Btn)
        self.Cntnr.addStretch(1)
        # -------
        self.setLayout(self.Cntnr)

class Win2Disply(QFrame):
    def __init__(self, parent):
        QFrame.__init__(self)

        self.setFrameShape(QFrame.StyledPanel)
        self.setLineWidth(0.2)
        # -------
        self.Cntnr = QVBoxLayout()
        self.Cntnr.addWidget(QTextEdit('This is Window 2 with whatever contents you want'))
        self.Win1Btn = QPushButton('>>')
        self.Win1Btn.clicked.connect(parent.RightArrow)
        self.Cntnr.addWidget(self.Win1Btn)
        self.Cntnr.addStretch(1)
        # -------
        self.setLayout(self.Cntnr)

class OptionButtons(QToolButton):
# Class OptionButtons ("Text", Connector) inherits from QToolButton
    def __init__(self, Text, Connector):
        QToolButton.__init__(self)

        self.setText(Text)
        self.setStyleSheet("font: bold;color: blue;height: 55px;width: 55px;")
        self.setIconSize(QSize(32,32))
        self.clicked.connect(Connector)

############################## Settings Class ##############################
class OptionSettings(QDialog):
    def __init__(self, parent):
        QDialog.__init__(self, parent)

        line = QFrame()
        line.setFrameShape(QFrame.HLine)
        line.setFrameShadow(QFrame.Sunken)

        self.btnWin1 = OptionButtons('Win One', self.ShowWindow1)
        self.btnWin2 = OptionButtons('Win Two', self.ShowWindow2)
      # Vertical Box for Buttons *************************************
        self.UpLeft  = QVBoxLayout()
        self.UpLeft.addWidget(self.btnWin1)
        self.UpLeft.addWidget(self.btnWin2)
        self.UpLeft.addStretch(1)
  # Display Area on Right
      # Widget Flip Display ******************************************
        self.UpRite   = QHBoxLayout()
        self.Contents = QStackedWidget()
        self.Contents.addWidget(QTextEdit('Nothing Selected'))
        self.Contents.addWidget(Win1Disply(self))
        self.Contents.addWidget(Win2Disply(self))
        self.Contents.addWidget(QTextEdit('Settings Saved'))
        self.Contents.setCurrentIndex(0)
        self.UpRite.addWidget(self.Contents)

  # Button and Display Area on Top
        self.Upper = QHBoxLayout()
        self.Upper.addLayout(self.UpLeft)
        self.Upper.addLayout(self.UpRite)
  # Save and Cancel Area on Bottom
        self.btnSave = QPushButton("Save")
        self.btnSave.clicked.connect(self.SaveSettings)
        self.btnCncl = QPushButton("Cancel")
        self.btnCncl.clicked.connect(self.close)
        self.Lower   = QHBoxLayout()
        self.Lower.addStretch(1)
        self.Lower.addWidget(self.btnSave)
        self.Lower.addWidget(self.btnCncl)
  # Entire Options Window Layout
        self.OuterBox = QVBoxLayout()
        self.OuterBox.addLayout(self.Upper)
        self.OuterBox.addLayout(self.Lower)
        self.setLayout(self.OuterBox)
        self.setWindowTitle('Settings')
        #Geometry(Left, Top, Width, Hight)
        self.setGeometry(250, 250, 550, 450)
        self.setModal(True)
        self.exec()

    def ShowWindow1(self):
        self.Contents.setCurrentIndex(1)

    def ShowWindow2(self):
        self.Contents.setCurrentIndex(2)

    def SaveSettings(self):
        self.Contents.setCurrentIndex(3)

    def RightArrow(self):
        if self.Contents.currentIndex() == 1:
           self.Contents.setCurrentIndex(2)
        else:
           self.Contents.setCurrentIndex(1)

class CenterPanel(QWidget):
    def __init__(self, MainWin):
        QWidget.__init__(self)

        CntrPane = QTextEdit('Center Panel is Placed Here')

        hbox = QHBoxLayout(self)
        hbox.addWidget(CntrPane)

        self.setLayout(hbox)

class MenuToolBar(QDockWidget):
    def __init__(self, MainWin):
        QDockWidget.__init__(self)
        self.MainWin = MainWin
        self.MainMenu = MainWin.menuBar()

        self.WndowMenu  = self.MainMenu.addMenu('Windows')

        self.OptnAct = QAction('Options', self)
        self.OptnAct.setStatusTip('Open the Options Window')
        self.OptnAct.triggered.connect(MainWin.ShowOptions)

        self.WndowMenu.addAction(self.OptnAct)

        self.InitToolBar(MainWin)

    def InitToolBar(self, MainWin):
        self.mainToolBar = MainWin.addToolBar("Quick Access")

        self.mainToolBar.addAction(self.OptnAct)

class UI_MainWindow(QMainWindow):
    def __init__(self):
        super(UI_MainWindow, self).__init__()
        self.setWindowTitle('Main Window')

      # Left, Top, Width, Height
        self.setGeometry(200, 200, 550, 550)

        self.CenterPane = CenterPanel(self)
        self.setCentralWidget(self.CenterPane)

        self.MenuToolBar = MenuToolBar(self)

    def ShowOptions(self):
        self.Options = OptionSettings(self)

if __name__ == '__main__':
    MainApp = QApplication([])

    MainGui = UI_MainWindow()
    MainGui.show()

    sysExit(MainApp.exec_())

Answer 5

如果在堆疊的小部件中確實需要箭頭，則另一種解決方案是實現自己的“ Promoted Widget”：它允許您使用自定義小部件創建設計，這可能會擴展Qt提供的基本小部件。 您將無法與Designer中自己的實現進行交互，但是一旦運行程序，您將獲得結果。

這是過程：創建要擴展的窗口小部件的自己的子類，定義您的自定義方法或覆蓋現有方法（請記住，某些私有方法需要特定的返回值類型，請查閱文檔）。 通常最好將創建的子類保存在單獨的文件中。 然后，在Designer中添加所需的小部件（在本例中為StackedWidget），右鍵單擊它並選擇“ Promote to ...”。 在將顯示的對話框中，在“ Promoted class name”字段中鍵入您創建的子類名稱（在下面的示例中，它將是“ StackedWidgetWithArrowButtons”），並在“ header file”字段中包含它的文件：將被視為python導入，因此請不要添加結尾的“ .py”，請記住，如果將其保存在子目錄中，則需要完整的“模塊”路徑，例如，“ mysubclasses.customstackwidget”（如果該文件）是“ mysubclasses”目錄中的“ customstackwidget”。 保存ui，進行編譯並運行程序。

class StackedWidgetWithArrowButtons(QtWidgets.QStackedWidget):
    def __init__(self, *args, **kwargs):
        QtWidgets.QStackedWidget.__init__(self, *args, **kwargs)
        self.backwardButton = QtWidgets.QToolButton(self)
        self.backwardButton.setIcon(self.style().standardIcon(QtWidgets.QStyle.SP_ArrowLeft))
        self.backwardButton.setMaximumSize(24, 24)
        self.backwardButton.setFocusPolicy(QtCore.Qt.NoFocus)
        self.forwardButton = QtWidgets.QToolButton(self)
        self.forwardButton.setIcon(self.style().standardIcon(QtWidgets.QStyle.SP_ArrowRight))
        self.forwardButton.setMaximumSize(24, 24)
        self.forwardButton.setFocusPolicy(QtCore.Qt.NoFocus)
        self.currentChanged.connect(self.checkSwitchButtons)

    def checkSwitchButtons(self):
        self.forwardButton.setEnabled(self.currentIndex() < self.count() - 1)
        self.backwardButton.setEnabled(self.currentIndex() > 0)

    def addWidget(self, widget):
        # this is a private method of QStackedWidget that is called when 
        # the ui is being built by the program, we just implement it 
        # to ensure that the buttons are correctly enabled;
        # the index *has* to be returned
        index = QtWidgets.QStackedWidget.addWidget(self, widget)
        self.checkSwitchButtons()
        return index

    def removeWidget(self, widget):
        # not necessary, but in case you want to remove widgets in the 
        # future, it will check buttons again
        index = QtWidgets.QStackedWidget.removeWidget(self, widget)
        self.checkSwitchButtons()
        return index

    def mousePressEvent(self, event):
        # due to the way QStackedWidget is implemented, children widgets
        # that are not in its layout might not receive mouse events,
        # but we just need to track clicks so this is enough
        if event.button() == QtCore.Qt.LeftButton:
            if event.pos() in self.backwardButton.geometry():
                self.setCurrentIndex(self.currentIndex() - 1)
            elif event.pos() in self.forwardButton.geometry():
                self.setCurrentIndex(self.currentIndex() + 1)

    def resizeEvent(self, event):
        # the base class resizeEvent *has* to be called, otherwise 
        # you could encounter problems with children widgets
        QtWidgets.QStackedWidget.resizeEvent(self, event)

        # now ensure that the buttons are always placed on the top
        # right corner; this positioning is completely manual and you
        # have to take button sizes in consideration to avoid 
        # overlapping buttons; obviously you can place them wherever
        # you want.
        self.forwardButton.move(self.rect().right() - self.forwardButton.width(), 0)
        self.backwardButton.move(self.forwardButton.x() - self.backwardButton.width(), 0)

如果您不希望按鈕（或者您不喜歡按鈕的顯示方式），則可以實現自己的paintEvent。 在這種情況下，我使用QPolygons創建了小三角形。

class StackedWidgetWithTriangles(QtWidgets.QStackedWidget):
    def __init__(self, *args, **kwargs):
        QtWidgets.QStackedWidget.__init__(self, *args, **kwargs)
        self.backwardRect = QtCore.QRect(0, 0, 16, 16)
        self.forwardRect = QtCore.QRect(0, 0, 16, 16)
        self.forwardArrow = QtGui.QPolygon([QtCore.QPoint(-6, -6), QtCore.QPoint(6, 0), QtCore.QPoint(-6, 6)])
        self.backwardArrow = QtGui.QPolygon([QtCore.QPoint(6, -6), QtCore.QPoint(-6, 0), QtCore.QPoint(6, 6)])

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            if event.pos() in self.backwardRect:
                self.setCurrentIndex(self.currentIndex() - 1)
            elif event.pos() in self.forwardRect:
                self.setCurrentIndex(self.currentIndex() + 1)

    def resizeEvent(self, event):
        QtWidgets.QStackedWidget.resizeEvent(self, event)
        self.forwardRect.moveLeft(self.rect().right() - self.forwardRect.width())
        self.backwardRect.moveLeft(self.forwardRect.x() - self.forwardRect.width())

    def paintEvent(self, event):
        qp = QtGui.QPainter(self)
        qp.setRenderHints(qp.Antialiasing)
        # set colors according to the possibility of going back or forward,
        # showing a "disabled" arrow whenever it's not possible
        if self.currentIndex() > 0:
            qp.setPen(QtCore.Qt.darkGray)
            qp.setBrush(QtCore.Qt.black)
        else:
            qp.setPen(QtCore.Qt.lightGray)
            qp.setBrush(QtCore.Qt.transparent)
        qp.drawPolygon(self.backwardArrow.translated(self.backwardRect.center()))
        if self.currentIndex() < self.count() - 1:
            qp.setPen(QtCore.Qt.darkGray)
            qp.setBrush(QtCore.Qt.black)
        else:
            qp.setPen(QtCore.Qt.lightGray)
            qp.setBrush(QtCore.Qt.transparent)
        qp.drawPolygon(self.forwardArrow.translated(self.forwardRect.center()))