在较为大型复杂，功能较多的应用程序中，我们通常继承QMainWindow类来进行开发。该主窗口为搭建应用用户界面提供了非常好的框架，请看下图：
可以看出该主窗口类为我们提供了菜单栏(Menu Bar)、工具栏(Tool Bar)、控件停靠区域(Dock Widgets)和状态栏(Status Bar)，我们可以往其中加入很多自己想要的东西，这也使得我们可以快速地开发一个功能复杂并且界面友好的应用程序
例子一记事本应用
接下来我们完成一个简易的记事本应用来了解一下QMainWindow的用法
#资料 https://blog.csdn.net/La_vie_est_belle/article/details/82819766 import sys
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import QMimeData
from PyQt5.QtWidgets import QApplication, QMainWindow, QTextEdit, QAction, QFileDialog, QMessageBox,\
QFontDialog, QColorDialog class Demo(QMainWindow):
is_saved = True
is_saved_first = True
path = '' def __init__(self):
super(Demo, self).__init__()
self.file_menu = self.menuBar().addMenu('File') #给菜单栏添加一个菜单
self.edit_menu = self.menuBar().addMenu('Edit')
self.help_menu = self.menuBar().addMenu('Help') self.file_toolbar = self.addToolBar('File') #给工具栏添加一个按钮
self.edit_toolbar = self.addToolBar('Edit') self.status_bar = self.statusBar() #设置一个状态栏
#接下来我们只需要往菜单栏和工具栏上面添加各种动作——也就是QAction，该类通常与菜单栏和工具栏搭配使用。可以将一个动作看作一种命令，每当用户点击某个动作时，就会触发某种命令，程序从而执行相应的命令
self.new_action = QAction('New', self) #实例化一个动作
self.open_action = QAction('Open', self)
self.save_action = QAction('Save', self)
self.save_as_action = QAction('Save As', self)
self.close_action = QAction('Close', self)
self.cut_action = QAction('Cut', self)
self.copy_action = QAction('Copy', self)
self.paste_action = QAction('Paste', self)
self.font_action = QAction('Font', self)
self.color_action = QAction('Color', self)
self.about_action = QAction('Qt', self) self.text_edit = QTextEdit(self)
self.mime_data = QMimeData()
self.clipboard = QApplication.clipboard() self.setCentralWidget(self.text_edit) # 设置*控件
self.resize(450, 600) self.menu_init()
self.toolbar_init()
self.status_bar_init()
self.action_init() #执行动作函数
self.text_edit_int() def action_init(self): #动作函数
#图片下载地址：链接: https://pan.baidu.com/s/1Rp2-G_8PdvFfDIoIesMNEg 提取码: ag8w
self.new_action.setIcon(QIcon('images/f1.ico')) # 给动作设置图标(菜单项的左侧显示，按钮显示)
self.new_action.setShortcut('Ctrl+N') #给动作设置快捷键
self.new_action.setToolTip('创建新文件') #设置气泡提示【鼠标在工具栏按钮上时提示的内容】
self.new_action.setStatusTip('Create a new file')#设置在状态栏提示的信息。当鼠标停留在该动作上时，状态栏会显示相应的信息
self.new_action.triggered.connect(self.new_func) #动作的触发信号
#
#self.open_action.setIcon(QIcon('images/open.ico'))
self.open_action.setShortcut('Ctrl+O')
self.open_action.setToolTip('Open an existing file')
self.open_action.setStatusTip('Open an existing file')
self.open_action.triggered.connect(self.open_file_func)
#
#self.save_action.setIcon(QIcon('images/save.ico'))
self.save_action.setShortcut('Ctrl+S')
self.save_action.setToolTip('Save the file')
self.save_action.setStatusTip('Save the file')
self.save_action.triggered.connect(lambda: self.save_func(self.text_edit.toHtml()))
#
#self.save_as_action.setIcon(QIcon('images/save_as.ico'))
self.save_as_action.setShortcut('Ctrl+A')
self.save_as_action.setToolTip('Save the file to a specified location')
self.save_as_action.setStatusTip('Save the file to a specified location')
self.save_as_action.triggered.connect(lambda: self.save_as_func(self.text_edit.toHtml()))
#
#self.close_action.setIcon(QIcon('images/close.ico'))
self.close_action.setShortcut('Ctrl+E')
self.close_action.setToolTip('Close the window')
self.close_action.setStatusTip('Close the window')
self.close_action.triggered.connect(self.close_func)
#
#self.cut_action.setIcon(QIcon('images/cut.ico'))
self.cut_action.setShortcut('Ctrl+X')
self.cut_action.setToolTip('Cut the text to clipboard')
self.cut_action.setStatusTip('Cut the text')
self.cut_action.triggered.connect(self.cut_func)
#
# self.copy_action.setIcon(QIcon('images/copy.ico'))
self.copy_action.setShortcut('Ctrl+C')
self.copy_action.setToolTip('Copy the text')
self.copy_action.setStatusTip('Copy the text')
self.copy_action.triggered.connect(self.copy_func)
#
# self.paste_action.setIcon(QIcon('images/paste.ico'))
self.paste_action.setShortcut('Ctrl+V')
self.paste_action.setToolTip('Paste the text')
self.paste_action.setStatusTip('Paste the text')
self.paste_action.triggered.connect(self.paste_func)
#
# self.font_action.setIcon(QIcon('images/font.ico'))
self.font_action.setShortcut('Ctrl+T')
self.font_action.setToolTip('Change the font')
self.font_action.setStatusTip('Change the font')
self.font_action.triggered.connect(self.font_func)
#
self.color_action.setIcon(QIcon('images/color.ico'))
self.color_action.setShortcut('Ctrl+R')
self.color_action.setToolTip('Change the color')
self.color_action.setStatusTip('Change the color')
self.color_action.triggered.connect(self.color_func)
#
# self.about_action.setIcon(QIcon('images/about.ico'))
# self.about_action.setShortcut('Ctrl+Q')
# self.about_action.setToolTip('What is Qt?')
# self.about_action.setStatusTip('What is Qt?')
# self.about_action.triggered.connect(self.about_func) def text_edit_int(self):
self.text_edit.textChanged.connect(self.text_changed_func) def text_changed_func(self):
if self.text_edit.toPlainText():
self.is_saved = False
else:
self.is_saved = True def font_func(self):
font, ok = QFontDialog.getFont()
if ok:
self.text_edit.setFont(font) def color_func(self):
color = QColorDialog.getColor()
if color.isValid():
self.text_edit.setTextColor(color) def paste_func(self):
self.text_edit.insertHtml(self.clipboard.mimeData().html()) def copy_func(self):
self.mime_data.setHtml(self.text_edit.textCursor().selection().toHtml())
self.clipboard.setMimeData(self.mime_data) def cut_func(self):
self.mime_data.setHtml(self.text_edit.textCursor().selection().toHtml())
self.clipboard.setMimeData(self.mime_data)
self.text_edit.textCursor().removeSelectedText() def close_func(self):
if not self.is_saved:
choice = QMessageBox.question(self, 'Save File', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func(self.text_edit.toHtml())
self.close()
elif choice == QMessageBox.No:
self.close()
else:
pass def closeEvent(self, QCloseEvent):
if not self.is_saved:
choice = QMessageBox.question(self, 'Save File', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func(self.text_edit.toHtml())
QCloseEvent.accept()
elif choice == QMessageBox.No:
QCloseEvent.accept()
else:
QCloseEvent.ignore() def save_as_func(self, text):
self.path, _ = QFileDialog.getSaveFileName(self, 'Save File', './', 'Files (*.html *.txt *.log)')
if self.path:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True
self.is_saved_first = False def open_file_func(self):
if not self.is_saved:
choice = QMessageBox.question(self, '', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func()
file, _ = QFileDialog.getOpenFileName(self, 'Open File', './', 'Files (*.html *.txt *.log)')
if file:
with open(file, 'r') as f:
self.text_edit.clear()
self.text_edit.setText(f.read())
self.is_saved = True
elif choice == QMessageBox.No:
file, _ = QFileDialog.getOpenFileName(self, 'Open File', './', 'Files (*.html *.txt *.log)')
if file:
with open(file, 'r') as f:
self.text_edit.clear()
self.text_edit.setText(f.read())
self.is_saved = True
else:
pass
else:
file, _ = QFileDialog.getOpenFileName(self, 'Open File', './', 'Files (*.html *.txt *.log)')
if file:
with open(file, 'r') as f:
self.text_edit.clear()
self.text_edit.setText(f.read())
self.is_saved = True def new_func(self):
if not self.is_saved:
choice = QMessageBox.question(self, '', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func()
self.text_edit.clear()
elif choice == QMessageBox.No:
self.text_edit.clear()
else:
pass
else:
self.text_edit.clear() def save_func(self, text):
if self.is_saved_first:
self.save_as_func(text)
else:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True def save_as_func(self, text):
self.path, _ = QFileDialog.getSaveFileName(self, 'Save File', './', 'Files (*.html *.txt *.log)')
if self.path:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True
self.is_saved_first = False def status_bar_init(self):
self.status_bar.showMessage('Ready to compose') #设置状态栏显示的内容 def toolbar_init(self):
self.file_toolbar.addAction(self.new_action) #给工具栏添加按钮动作
#注意：菜单栏、工具栏相同动作是同一个QAction对象
self.file_toolbar.addAction(self.open_action)
self.file_toolbar.addAction(self.save_action)
self.file_toolbar.addAction(self.save_as_action) self.edit_toolbar.addAction(self.cut_action)
self.edit_toolbar.addAction(self.copy_action)
self.edit_toolbar.addAction(self.paste_action)
self.edit_toolbar.addAction(self.font_action)
self.edit_toolbar.addAction(self.color_action) def save_func(self, text):
if self.is_saved_first:
self.save_as_func(text)
else:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True def menu_init(self):
self.file_menu.addAction(self.new_action) #给菜单添加一个动作
self.file_menu.addAction(self.open_action)
self.file_menu.addAction(self.save_action)
self.file_menu.addAction(self.save_as_action)
self.file_menu.addSeparator() #加一个分割条
self.file_menu.addAction(self.close_action) self.edit_menu.addAction(self.cut_action)
self.edit_menu.addAction(self.copy_action)
self.edit_menu.addAction(self.paste_action)
self.edit_menu.addSeparator()
self.edit_menu.addAction(self.font_action)
self.edit_menu.addAction(self.color_action) self.help_menu.addAction(self.about_action) if __name__ == '__main__':
app = QApplication(sys.argv)
demo = Demo()
demo.show()
sys.exit(app.exec_())
启动画面QSplashScreen
#资料 https://blog.csdn.net/La_vie_est_belle/article/details/82819766 import sys
import time
from PyQt5.QtGui import QIcon, QPixmap
from PyQt5.QtCore import QMimeData, Qt
from PyQt5.QtWidgets import QApplication, QMainWindow, QTextEdit, QAction, QFileDialog, QMessageBox,\
QFontDialog, QColorDialog, QSplashScreen class Demo(QMainWindow):
is_saved = True
is_saved_first = True
path = '' def __init__(self):
super(Demo, self).__init__()
self.file_menu = self.menuBar().addMenu('File') #给菜单栏添加一个菜单
self.edit_menu = self.menuBar().addMenu('Edit')
self.help_menu = self.menuBar().addMenu('Help') self.file_toolbar = self.addToolBar('File') #给工具栏添加一个按钮
self.edit_toolbar = self.addToolBar('Edit') self.status_bar = self.statusBar() #设置一个状态栏
#接下来我们只需要往菜单栏和工具栏上面添加各种动作——也就是QAction，该类通常与菜单栏和工具栏搭配使用。可以将一个动作看作一种命令，每当用户点击某个动作时，就会触发某种命令，程序从而执行相应的命令
self.new_action = QAction('New', self) #实例化一个动作
self.open_action = QAction('Open', self)
self.save_action = QAction('Save', self)
self.save_as_action = QAction('Save As', self)
self.close_action = QAction('Close', self)
self.cut_action = QAction('Cut', self)
self.copy_action = QAction('Copy', self)
self.paste_action = QAction('Paste', self)
self.font_action = QAction('Font', self)
self.color_action = QAction('Color', self)
self.about_action = QAction('Qt', self) self.text_edit = QTextEdit(self)
self.mime_data = QMimeData()
self.clipboard = QApplication.clipboard() self.setCentralWidget(self.text_edit) # 设置*控件
self.resize(450, 600) self.menu_init()
self.toolbar_init()
self.status_bar_init()
self.action_init() #执行动作函数
self.text_edit_int() def action_init(self): #动作函数
#图片下载地址：链接: https://pan.baidu.com/s/1Rp2-G_8PdvFfDIoIesMNEg 提取码: ag8w
self.new_action.setIcon(QIcon('images/f1.ico')) # 给动作设置图标
self.new_action.setShortcut('Ctrl+N') #给动作设置快捷键
self.new_action.setToolTip('创建新文件') #设置气泡提示【鼠标在工具栏按钮上时提示的内容】
self.new_action.setStatusTip('Create a new file')#设置在状态栏提示的信息。当鼠标停留在该动作上时，状态栏会显示相应的信息
self.new_action.triggered.connect(self.new_func) #动作的触发信号
#
#self.open_action.setIcon(QIcon('images/open.ico'))
self.open_action.setShortcut('Ctrl+O')
self.open_action.setToolTip('Open an existing file')
self.open_action.setStatusTip('Open an existing file')
self.open_action.triggered.connect(self.open_file_func)
#
#self.save_action.setIcon(QIcon('images/save.ico'))
self.save_action.setShortcut('Ctrl+S')
self.save_action.setToolTip('Save the file')
self.save_action.setStatusTip('Save the file')
self.save_action.triggered.connect(lambda: self.save_func(self.text_edit.toHtml()))
#
#self.save_as_action.setIcon(QIcon('images/save_as.ico'))
self.save_as_action.setShortcut('Ctrl+A')
self.save_as_action.setToolTip('Save the file to a specified location')
self.save_as_action.setStatusTip('Save the file to a specified location')
self.save_as_action.triggered.connect(lambda: self.save_as_func(self.text_edit.toHtml()))
#
#self.close_action.setIcon(QIcon('images/close.ico'))
self.close_action.setShortcut('Ctrl+E')
self.close_action.setToolTip('Close the window')
self.close_action.setStatusTip('Close the window')
self.close_action.triggered.connect(self.close_func)
#
#self.cut_action.setIcon(QIcon('images/cut.ico'))
self.cut_action.setShortcut('Ctrl+X')
self.cut_action.setToolTip('Cut the text to clipboard')
self.cut_action.setStatusTip('Cut the text')
self.cut_action.triggered.connect(self.cut_func)
#
# self.copy_action.setIcon(QIcon('images/copy.ico'))
self.copy_action.setShortcut('Ctrl+C')
self.copy_action.setToolTip('Copy the text')
self.copy_action.setStatusTip('Copy the text')
self.copy_action.triggered.connect(self.copy_func)
#
# self.paste_action.setIcon(QIcon('images/paste.ico'))
self.paste_action.setShortcut('Ctrl+V')
self.paste_action.setToolTip('Paste the text')
self.paste_action.setStatusTip('Paste the text')
self.paste_action.triggered.connect(self.paste_func)
#
# self.font_action.setIcon(QIcon('images/font.ico'))
self.font_action.setShortcut('Ctrl+T')
self.font_action.setToolTip('Change the font')
self.font_action.setStatusTip('Change the font')
self.font_action.triggered.connect(self.font_func)
#
self.color_action.setIcon(QIcon('images/color.ico'))
self.color_action.setShortcut('Ctrl+R')
self.color_action.setToolTip('Change the color')
self.color_action.setStatusTip('Change the color')
self.color_action.triggered.connect(self.color_func)
#
# self.about_action.setIcon(QIcon('images/about.ico'))
# self.about_action.setShortcut('Ctrl+Q')
# self.about_action.setToolTip('What is Qt?')
# self.about_action.setStatusTip('What is Qt?')
# self.about_action.triggered.connect(self.about_func) def text_edit_int(self):
self.text_edit.textChanged.connect(self.text_changed_func) def text_changed_func(self):
if self.text_edit.toPlainText():
self.is_saved = False
else:
self.is_saved = True def font_func(self):
font, ok = QFontDialog.getFont()
if ok:
self.text_edit.setFont(font) def color_func(self):
color = QColorDialog.getColor()
if color.isValid():
self.text_edit.setTextColor(color) def paste_func(self):
self.text_edit.insertHtml(self.clipboard.mimeData().html()) def copy_func(self):
self.mime_data.setHtml(self.text_edit.textCursor().selection().toHtml())
self.clipboard.setMimeData(self.mime_data) def cut_func(self):
self.mime_data.setHtml(self.text_edit.textCursor().selection().toHtml())
self.clipboard.setMimeData(self.mime_data)
self.text_edit.textCursor().removeSelectedText() def close_func(self):
if not self.is_saved:
choice = QMessageBox.question(self, 'Save File', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func(self.text_edit.toHtml())
self.close()
elif choice == QMessageBox.No:
self.close()
else:
pass def closeEvent(self, QCloseEvent):
if not self.is_saved:
choice = QMessageBox.question(self, 'Save File', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func(self.text_edit.toHtml())
QCloseEvent.accept()
elif choice == QMessageBox.No:
QCloseEvent.accept()
else:
QCloseEvent.ignore() def save_as_func(self, text):
self.path, _ = QFileDialog.getSaveFileName(self, 'Save File', './', 'Files (*.html *.txt *.log)')
if self.path:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True
self.is_saved_first = False def open_file_func(self):
if not self.is_saved:
choice = QMessageBox.question(self, '', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func()
file, _ = QFileDialog.getOpenFileName(self, 'Open File', './', 'Files (*.html *.txt *.log)')
if file:
with open(file, 'r') as f:
self.text_edit.clear()
self.text_edit.setText(f.read())
self.is_saved = True
elif choice == QMessageBox.No:
file, _ = QFileDialog.getOpenFileName(self, 'Open File', './', 'Files (*.html *.txt *.log)')
if file:
with open(file, 'r') as f:
self.text_edit.clear()
self.text_edit.setText(f.read())
self.is_saved = True
else:
pass
else:
file, _ = QFileDialog.getOpenFileName(self, 'Open File', './', 'Files (*.html *.txt *.log)')
if file:
with open(file, 'r') as f:
self.text_edit.clear()
self.text_edit.setText(f.read())
self.is_saved = True def new_func(self):
if not self.is_saved:
choice = QMessageBox.question(self, '', 'Do you want to save the text?',
QMessageBox.Yes | QMessageBox.No | QMessageBox.Cancel)
if choice == QMessageBox.Yes:
self.save_func()
self.text_edit.clear()
elif choice == QMessageBox.No:
self.text_edit.clear()
else:
pass
else:
self.text_edit.clear() def save_func(self, text):
if self.is_saved_first:
self.save_as_func(text)
else:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True def save_as_func(self, text):
self.path, _ = QFileDialog.getSaveFileName(self, 'Save File', './', 'Files (*.html *.txt *.log)')
if self.path:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True
self.is_saved_first = False def status_bar_init(self):
self.status_bar.showMessage('Ready to compose') #设置状态栏显示的内容 def toolbar_init(self):
self.file_toolbar.addAction(self.new_action) #给工具栏添加按钮动作
#注意：菜单栏、工具栏相同动作是同一个QAction对象
self.file_toolbar.addAction(self.open_action)
self.file_toolbar.addAction(self.save_action)
self.file_toolbar.addAction(self.save_as_action) self.edit_toolbar.addAction(self.cut_action)
self.edit_toolbar.addAction(self.copy_action)
self.edit_toolbar.addAction(self.paste_action)
self.edit_toolbar.addAction(self.font_action)
self.edit_toolbar.addAction(self.color_action) def save_func(self, text):
if self.is_saved_first:
self.save_as_func(text)
else:
with open(self.path, 'w') as f:
f.write(text)
self.is_saved = True def menu_init(self):
self.file_menu.addAction(self.new_action) #给菜单添加一个动作
self.file_menu.addAction(self.open_action)
self.file_menu.addAction(self.save_action)
self.file_menu.addAction(self.save_as_action)
self.file_menu.addSeparator() #加一个分割条
self.file_menu.addAction(self.close_action) self.edit_menu.addAction(self.cut_action)
self.edit_menu.addAction(self.copy_action)
self.edit_menu.addAction(self.paste_action)
self.edit_menu.addSeparator()
self.edit_menu.addAction(self.font_action)
self.edit_menu.addAction(self.color_action) self.help_menu.addAction(self.about_action) if __name__ == '__main__':
app = QApplication(sys.argv)
splash = QSplashScreen() #实例化启动画面对象
splash.setPixmap(QPixmap('images/splash.jpg')) #设置启动画面的图片
splash.show() #显示启动画面
splash.showMessage('欢迎使用PYQT5',
Qt.AlignBottom | Qt.AlignCenter, Qt.white)
#设置在启动画面上要显示的文字
#参数1：要显示的文本
#参数2：显示的位置。Qt.AlignBottom(垂直方向的位置) 底部；Qt.AlignCenter(水平方向的位置) 居中
#参数3：文字的颜色
time.sleep(2) demo = Demo()
demo.show()
splash.finish(demo)#把显示画面切换到主窗口
sys.exit(app.exec_())
self.statusbar.addWidget(self.labviewcorrd) #给状态栏添加控件
天子骄龙