在 Qt Designer 中使用自定义 PySide2 小部件

Question

我正在寻找一种在 Qt Designer 中有效使用自定义小部件的方法，该小部件由 Qt for Python (PySide2) 编写。

我发现，可以使用基本小部件设计 GUI，然后只需将类换成 UI 文件中的自定义小部件并通知 QUiLoader 关于子类 loader.registerCustomWidget(MyMainWindow)，然后打开在 Qt Designer 中再次使用它并不能很好地工作。

我在this similar question for PyQt 中读到，您必须为自定义小部件编写一个插件。 PySide2是否也存在这种可能性？

一些示例代码：

custom_widget.py：

import sys

from PySide2.QtUiTools import QUiLoader
from PySide2.QtWidgets import QApplication, QMainWindow, QAction, QMessageBox, QFileDialog, QTextBrowser
from PySide2.QtCore import QFile


class MyMainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setWindowTitle("Demo QtWidget App")

    def closeEvent(self, event):
        msgBox = QMessageBox()
        msgBox.setWindowTitle("Quit?")
        msgBox.setText("Exit application?")
        msgBox.setStandardButtons(QMessageBox.Yes | QMessageBox.No)
        msgBox.setDefaultButton(QMessageBox.No)
        ret = msgBox.exec_()
        if ret == QMessageBox.Yes:
            event.accept()
        else:
            event.ignore()


if __name__ == '__main__':
    app = QApplication([])
    file = QFile("custom_widget_original.ui")
    #file = QFile("custom_widget_modified.ui")
    file.open(QFile.ReadOnly)
    loader = QUiLoader()
    loader.registerCustomWidget(MyMainWindow)
    main_window = loader.load(file)
    main_window.show()
    sys.exit(app.exec_())

custom_widget_original.ui

使用此版本，应用程序将毫无疑问地关闭。

<?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="QGridLayout" name="gridLayout">
    <item row="0" column="0">
     <widget class="QLabel" name="label_2">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
    <item row="0" column="2">
     <widget class="QLabel" name="label">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
    <item row="0" column="1">
     <widget class="QLabel" name="label_3">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
   <widget class="QMenu" name="menuFile">
    <property name="title">
     <string>File</string>
    </property>
    <addaction name="actionExit"/>
   </widget>
   <addaction name="menuFile"/>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
  <action name="actionExit">
   <property name="text">
    <string>Exit</string>
   </property>
  </action>
 </widget>
 <resources/>
 <connections>
  <connection>
   <sender>actionExit</sender>
   <signal>triggered()</signal>
   <receiver>MainWindow</receiver>
   <slot>close()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>-1</x>
     <y>-1</y>
    </hint>
    <hint type="destinationlabel">
     <x>399</x>
     <y>299</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

custom_widget_modified.ui

在此版本中，系统会询问您是否真的要退出。

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="MyMainWindow" 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">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>155</width>
     <height>15</height>
    </rect>
   </property>
   <layout class="QGridLayout" name="gridLayout">
    <item row="0" column="0">
     <widget class="QLabel" name="label_2">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
    <item row="0" column="2">
     <widget class="QLabel" name="label">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
    <item row="0" column="1">
     <widget class="QLabel" name="label_3">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
   <widget class="QMenu" name="menuFile">
    <property name="title">
     <string>File</string>
    </property>
    <addaction name="actionExit"/>
   </widget>
   <addaction name="menuFile"/>
  </widget>
  <widget class="QStatusBar" name="statusbar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>3</width>
     <height>18</height>
    </rect>
   </property>
  </widget>
  <action name="actionExit">
   <property name="text">
    <string>Exit</string>
   </property>
  </action>
 </widget>
 <customwidgets>
  <customwidget>
   <class>MyMainWindow</class>
   <extends>QWidget</extends>
   <header>mymainwindow.h</header>
   <container>1</container>
  </customwidget>
 </customwidgets>
 <resources/>
 <connections>
  <connection>
   <sender>actionExit</sender>
   <signal>triggered()</signal>
   <receiver>MainWindow</receiver>
   <slot>close()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>-1</x>
     <y>-1</y>
    </hint>
    <hint type="destinationlabel">
     <x>399</x>
     <y>299</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

<customwidgets> 段是 Qt Designer 再次打开后添加的。

修改后Qt Designer没有正确放置三个标签。

Answer 1

在 Qt Designer 中使用自定义小部件有两种主要方法：

1。推广小部件：

这是最简单、最省力的方法，如果是内部小部件，您只需右键单击小部件并选择Promote To ...，然后在：

• 基类名称选择你继承的类
• Promoted Class Name 放置类a的名称
• 头文件放置文件的路径，将扩展名.py更改为.h

上面所做的是生成以下内容：

...
    <widget class="RadialBar" name="widget" native="true"/>
...
 <customwidgets>
  <customwidget>
   <class>RadialBar</class>
   <extends>QWidget</extends>
   <header>radialbar.h</header>
   <container>1</container>
  </customwidget>
 </customwidgets>
...

即更改类，在customwidget中添加一个指向类名的字段：<class> NAME_OF_CLASS </class>，它们继承的类名<extends>CLASS_EXTENDS</extends>和文件路径更改文件扩展名从.py到.h<header>PATH_OF_FILE.h</header>，也就是和你输入表格一样的数据。

在根部件的情况下，它不能通过 Qt 设计器完成，但我看到你已经理解了逻辑但你没有正确修改所有内容，你的主要错误是指出它们继承的类

 <customwidgets>
  <customwidget>
   <class>MyMainWindow</class>
   <extends>QMainWindow</extends> <----
   <header>mymainwindow.h</header>
   <container>1</container>
  </customwidget>
 </customwidgets>

所以正确的文件是：

custom_widget_modified.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="MyMainWindow" 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">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>155</width>
     <height>15</height>
    </rect>
   </property>
   <layout class="QGridLayout" name="gridLayout">
    <item row="0" column="0">
     <widget class="QLabel" name="label_2">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
    <item row="0" column="2">
     <widget class="QLabel" name="label">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
    <item row="0" column="1">
     <widget class="QLabel" name="label_3">
      <property name="text">
       <string>TextLabel</string>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
   <widget class="QMenu" name="menuFile">
    <property name="title">
     <string>File</string>
    </property>
    <addaction name="actionExit"/>
   </widget>
   <addaction name="menuFile"/>
  </widget>
  <widget class="QStatusBar" name="statusbar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>3</width>
     <height>18</height>
    </rect>
   </property>
  </widget>
  <action name="actionExit">
   <property name="text">
    <string>Exit</string>
   </property>
  </action>
 </widget>
 <customwidgets>
  <customwidget>
   <class>MyMainWindow</class>
   <extends>QMainWindow</extends>
   <header>mymainwindow.h</header>
   <container>1</container>
  </customwidget>
 </customwidgets>
 <resources/>
 <connections>
  <connection>
   <sender>actionExit</sender>
   <signal>triggered()</signal>
   <receiver>MainWindow</receiver>
   <slot>close()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>-1</x>
     <y>-1</y>
    </hint>
    <hint type="destinationlabel">
     <x>399</x>
     <y>299</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

mymainwindow.py

import sys

from PySide2.QtUiTools import QUiLoader
from PySide2.QtWidgets import QApplication, QMainWindow, QMessageBox
from PySide2.QtCore import QFile


class MyMainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setWindowTitle("Demo QtWidget App")

    def closeEvent(self, event):
        msgBox = QMessageBox()
        msgBox.setWindowTitle("Quit?")
        msgBox.setText("Exit application?")
        msgBox.setStandardButtons(QMessageBox.Yes | QMessageBox.No)
        msgBox.setDefaultButton(QMessageBox.No)
        ret = msgBox.exec_()
        if ret == QMessageBox.Yes:
            event.accept()
        else:
            event.ignore()


if __name__ == '__main__':
    app = QApplication([])
    file = QFile("custom_widget_modified.ui")
    file.open(QFile.ReadOnly)
    loader = QUiLoader()
    loader.registerCustomWidget(MyMainWindow)
    main_window = loader.load(file)
    main_window.show()
    sys.exit(app.exec_())

2。推广小部件：