python - PYQT5 中的布局大小

Question

我想让 QTabWidget 的布局在正常模式(未最大化)下比 PlainTextEdit 更宽。但是当窗口处于最大模式时，我希望它如图所示(QTabwidget 保持相同的形状，但 PlainTextEdit 会更大)

顺便说一句，我使用的是 Pyqt5 和 Python 3.6.3

代码:

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(829, 315)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.formLayout = QtWidgets.QFormLayout(self.centralwidget)
        self.formLayout.setObjectName("formLayout")
        self.verticalLayout_2 = QtWidgets.QVBoxLayout()
        self.verticalLayout_2.setObjectName("verticalLayout_2")
        self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
        self.tabWidget.setObjectName("tabWidget")
        self.tab = QtWidgets.QWidget()
        self.tab.setObjectName("tab")
        self.tabWidget.addTab(self.tab, "")
        self.tab_2 = QtWidgets.QWidget()
        self.tab_2.setObjectName("tab_2")
        self.tabWidget.addTab(self.tab_2, "")
        self.verticalLayout_2.addWidget(self.tabWidget)
        self.formLayout.setLayout(0, QtWidgets.QFormLayout.LabelRole, self.verticalLayout_2)
        self.verticalLayout = QtWidgets.QVBoxLayout()
        self.verticalLayout.setObjectName("verticalLayout")
        self.plainTextEdit = QtWidgets.QPlainTextEdit(self.centralwidget)
        self.plainTextEdit.setObjectName("plainTextEdit")
        self.verticalLayout.addWidget(self.plainTextEdit)
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setObjectName("pushButton")
        self.horizontalLayout.addWidget(self.pushButton)
        self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_2.setObjectName("pushButton_2")
        self.horizontalLayout.addWidget(self.pushButton_2)
        spacerItem = QtWidgets.QSpacerItem(30, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem)
        self.verticalLayout.addLayout(self.horizontalLayout)
        self.formLayout.setLayout(0, QtWidgets.QFormLayout.FieldRole, self.verticalLayout)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 829, 31))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "Tab 1"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_2), _translate("MainWindow", "Tab 2"))
        self.plainTextEdit.setPlainText(_translate("MainWindow", "PlainTextEdit"))
        self.pushButton.setText(_translate("MainWindow", "on"))
        self.pushButton_2.setText(_translate("MainWindow", "off"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Answer 1

当您使用 Qt Designer 时，您要做的第一件事就是创建以下内容:

为此，它遵循以下结构:

└── Horizontal Layout
    ├── Vertical Layout
    │   └── QTabWidget
    └── Vertical Layout
        └── Vertical Layout
            ├── QPlainTextEdit
            └── Horizontal Layout
                ├── QPushButton On
                ├── QPushButton Off
                └── QSpacerItem

对应的.ui为:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <layout class="QHBoxLayout" name="horizontalLayout_2">
    <item>
     <layout class="QVBoxLayout" name="verticalLayout_2">
      <item>
       <widget class="QTabWidget" name="tabWidget">
        <widget class="QWidget" name="tab">
         <attribute name="title">
          <string>Tab 1</string>
         </attribute>
        </widget>
        <widget class="QWidget" name="tab_2">
         <attribute name="title">
          <string>Tab 2</string>
         </attribute>
        </widget>
       </widget>
      </item>
     </layout>
    </item>
    <item>
     <layout class="QVBoxLayout" name="verticalLayout">
      <item>
       <widget class="QPlainTextEdit" name="plainTextEdit"/>
      </item>
      <item>
       <layout class="QHBoxLayout" name="horizontalLayout">
        <item>
         <widget class="QPushButton" name="pushButton">
          <property name="text">
           <string>on</string>
          </property>
         </widget>
        </item>
        <item>
         <widget class="QPushButton" name="pushButton_2">
          <property name="text">
           <string>off</string>
          </property>
         </widget>
        </item>
        <item>
         <spacer name="horizontalSpacer">
          <property name="orientation">
           <enum>Qt::Horizontal</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
            <width>40</width>
            <height>20</height>
           </size>
          </property>
         </spacer>
        </item>
       </layout>
      </item>
     </layout>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>24</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

然后用pyuic转成.py，那么你必须对生成的代码做如下改动:

改变:

self.verticalLayout_2.addWidget(self.tabWidget)

到:

self.tabWidget.setFixedHeight(300)
self.verticalLayout_2.addWidget(self.tabWidget, 0, QtCore.Qt.AlignTop)

---

完整代码:

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

# Form implementation generated from reading ui file 'untitled.ui'
#
# Created by: PyQt5 UI code generator 5.10.1
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout(self.centralwidget)
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.verticalLayout_2 = QtWidgets.QVBoxLayout()
        self.verticalLayout_2.setObjectName("verticalLayout_2")
        self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
        self.tabWidget.setObjectName("tabWidget")
        self.tab = QtWidgets.QWidget()
        self.tab.setObjectName("tab")
        self.tabWidget.addTab(self.tab, "")
        self.tab_2 = QtWidgets.QWidget()
        self.tab_2.setObjectName("tab_2")
        self.tabWidget.addTab(self.tab_2, "")
        self.tabWidget.setFixedHeight(300)
        self.verticalLayout_2.addWidget(self.tabWidget, 0, QtCore.Qt.AlignTop)
        self.horizontalLayout_2.addLayout(self.verticalLayout_2)
        self.verticalLayout = QtWidgets.QVBoxLayout()
        self.verticalLayout.setObjectName("verticalLayout")
        self.plainTextEdit = QtWidgets.QPlainTextEdit(self.centralwidget)
        self.plainTextEdit.setObjectName("plainTextEdit")
        self.verticalLayout.addWidget(self.plainTextEdit)
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setObjectName("pushButton")
        self.horizontalLayout.addWidget(self.pushButton)
        self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_2.setObjectName("pushButton_2")
        self.horizontalLayout.addWidget(self.pushButton_2)
        spacerItem = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem)
        self.verticalLayout.addLayout(self.horizontalLayout)
        self.horizontalLayout_2.addLayout(self.verticalLayout)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 24))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "Tab 1"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_2), _translate("MainWindow", "Tab 2"))
        self.pushButton.setText(_translate("MainWindow", "on"))
        self.pushButton_2.setText(_translate("MainWindow", "off"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())