PyQt：如何在QStackedWidget中切换小部件

Question

我在两个不同的页面(page1和page2)中放置了两个按钮(wgtbtnA和wgtbtnB)，它们都位于一个父对象(objectName: stackedWidget)中。我的困境是：当我运行代码时，这些箭头不会在PyQt中显示。为什么？如何从page1切换到page2或者反过来？

下面是一个展示我所询问内容的运行时图像:

Qt Designer:

我想保留这些小后退箭头。

以下是我的代码:

# -*- 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_())

- Jeremy Scott

Answer 1

您可以使用按钮来更改页面：{您的QPushButton}.clicked.connect(lambda: {您的QStackedWidget}.setCurrentIndex({另一个页面})) 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_())

启动应用：

点击按钮后：

点击另一个按钮后：

- eyllanesc

Answer 2

你在下面的消息中看到的设计师中的两个箭头不会转移到你的应用程序中，它是设计师中的一个功能，让你可以轻松地在它们之间切换。

- ECM

---

@ekhumoro：如果添加的数量受到限制怎么办？由于我是新手，原始帖子中不允许我添加超过2张图片。并非想要争论，但当你被限制在证明观点时所能添加的东西有限时，提供确切和清晰的信息确实很困难。因此，我为自己的无知道歉。也许您还有其他解决方案？如果有，我很愿意听取。最好的祝福，Jeremy - Jeremy Scott

@JeremyStiefel。无论如何编辑您的问题：只有具有必要声望的人才能稍后修复链接。您所能做的唯一限制是因为您没有足够的声望：因此简单的解决方案就是获得更多声望。 - ekhumoro

Answer 3

要实现从一个屏幕到另一个屏幕的箭头，您只需要传播这些箭头，确保它们出现在每个视图中--现在可以通过代码轻松完成，但无法确定在设计师中可能有多难。以下是一个类似于您可能想要的示例。

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_())

- Dennis Jensen

Answer 4

如果您真的需要在堆叠小部件中使用箭头，另一种解决方案是实现自己的“推广小部件”：它允许您使用自定义小部件创建设计，这些小部件可以扩展Qt提供的基本小部件。您无法在设计器中与自己的实现进行交互，但运行程序后将获得结果。

这是步骤：创建你自己的小部件子类以扩展它，定义你的自定义方法或覆盖现有的方法（请记住，某些私有方法需要特定的返回值类型，请查看文档）。 通常最好将你创建的子类保存在单独的文件中。 然后，在设计师中添加你需要的小部件（在本例中为StackedWidget），右键单击它并选择“提升为...”；在显示的对话框中，输入你创建的子类名称到“提升类名”字段中（在下面的示例中，它将是“StackedWidgetWithArrowButtons”），并将包含它的文件输入到“头文件”字段中：它将被视为Python导入，因此不要添加尾随的“.py”，并记住如果你将其保存在子目录中，你将需要完整的“模块”路径，例如“mysubclasses.customstackwidget”，如果文件在“mysubclasses”目录中名为“customstackwidget”。保存UI，编译并运行程序。

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)

如果您不想要按钮（或者您不喜欢它们的外观），您可以实现自己的paintEvent。在这种情况下，我使用QPolygons创建了小三角形。

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()))

- musicamante

Answer 5

你的ControlMainWindow类没有逻辑来在小部件之间进行切换。（而且我没有看到任何用于切换的箭头小部件）你需要为主类中的QTbuttons添加一个监听器，如下所示执行逻辑：

yourQTbutton.itemClicked.connect(self.functioWithUIchangingLogic)

- ECM

---

抱歉，我应该更具体地说明。我知道如何连接信号和槽。我的问题是，pyqt自动格式化的箭头放在哪里。通常，在stackedWidgets的右上角有两个黑色箭头。 - Jeremy Scott

你是在使用QT Designer来创建用户界面吗？如果是的话，那么你在设计师中看到的两个箭头不会转移到你的应用程序中，它只是设计师中的一个功能，让你可以轻松地在它们之间切换。 - ECM

明白了。所以没有编程的方式可以自动转移它们，对吗？ - Jeremy Scott