python PyQt5

# _*_ coding:utf-8 _*_
import sys
from PyQt5.QtWidgets import (QApplication, QWidget, QVBoxLayout,
                             QPushButton, QMainWindow)


class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.init_ui()

    def init_ui(self):
        self.setWindowTitle('关闭主窗口')
        # 设置窗口标题
        self.resize(600, 600)

        layout = QVBoxLayout()
        self.close_btn = QPushButton('关闭', self)

        layout.addWidget(self.close_btn)

        main_frame = QWidget()
        self.setCentralWidget(main_frame)
        main_frame.setLayout(layout)

        self.close_btn.clicked.connect(self.on_button_click)
        self.status = self.statusBar()
        self.status.showMessage('我是状态栏', 5000)

    def on_button_click(self):
        # 将信息显示在状态栏中
        sender = self.sender()

        msg = sender.text() + " 被按下了"
        status = self.statusBar()
        status.showMessage(msg, 5000)
        #self.showMaximized()
        

        # 程序退出
        app = QApplication.instance()
        app.quit()


if __name__ == "__main__":
    app = QApplication(sys.argv[1:])

    window = MainWindow()
    window.show()

    sys.exit(app.exec_())

　　===============================

import sys
from PyQt5.QtWidgets import *
from PyQt5.QtGui import QColor, QFont, QIcon, QKeySequence
from PyQt5.QtCore import Qt, QDate, QTime, QDateTime, QTimer
from PyQt5.QtPrintSupport import QPrinter, QPrintDialog, QPrintPreviewDialog
import os


class MainWindow(QMainWindow):

    def __init__(self, parent=None):
        super().__init__(parent)
        self.initUI()

    def initUI(self):
        self.setWindowTitle("主窗口示例")
        # self.resize(400,250)

        self.setup_centralWidget()
        self.setup_dockWidget()
        self.setup_statusBar()

        self.createActions()
        self.setup_menuBar()
        self.setup_toolBar()

    def setup_centralWidget(self):
        # 设置主窗口中心部件
        self.textEdit = QTextEdit()  # 初始化时换行符无效
        self.textEdit.setText("第一行\n第二行\n第三行\n")
        # self.textEdit.selectAll()
        self.setCentralWidget(self.textEdit)  # 指定主窗口中心部件

    def createActions(self):  # 创建动作
        # 打开文件动作
        self.fileOpenAction = QAction(QIcon("open.png"), "&Open", self)  # 动作在self中可用
        self.fileOpenAction.setShortcut(QKeySequence.Open)  # 设置标准化快捷键
        # self.fileOpenAction.setShortcut("Ctrl+O")# windows 系统下等效于
        self.fileOpenAction.setToolTip("打开文件")  # 工具栏提示文本
        self.fileOpenAction.setStatusTip("打开现有的文件")  # 状态栏提示文本
        self.fileOpenAction.triggered.connect(self.fileOpen)

        # 文件另存为动作
        self.fileSaveAsAction = QAction(QIcon("save.png"), "SaveAs", self)  # 动作在self中可用
        self.fileSaveAsAction.setShortcut(QKeySequence.SaveAs)  # 设置标准化快捷键
        # windows 系统下无快捷键
        self.fileSaveAsAction.setToolTip("另存为")  # 工具栏提示文本
        self.fileSaveAsAction.setStatusTip("文件另存为")  # 状态栏提示文本
        self.fileSaveAsAction.triggered.connect(self.fileSaveAs)

        # 动作分隔符
        self.separator = QAction(self)
        self.separator.setSeparator(True)

    def setup_menuBar(self):
        # 文件菜单
        self.fileMenu = self.menuBar().addMenu("&File")
        self.fileMenu.addAction(self.fileOpenAction)
        self.fileMenu.addAction(self.fileSaveAsAction)
        # self.fileMenu.addAction(self.separator)

    def fileOpen(self):
        fileName, filetype = QFileDialog.getOpenFileName(self,
                                                         "打开文件",
                                                         os.getcwd(),  # 设定起始路径为当前目录
                                                         "Text Files (*.txt)")  # 设置文件扩展名过滤,用双分号间隔
        if fileName != "":
            with open(fileName) as f:
                self.textEdit.setText(f.read())

    def fileSaveAs(self):
        fileName, filetype = QFileDialog.getSaveFileName(self,
                                                         "文件另存为",
                                                         os.getcwd(),  # 起始路径
                                                         "Text Files (*.txt);;Html Files (*.html)")  # 设置文件扩展名过滤,用双分号间隔
        if fileName == "": return
        if filetype == "Text Files (*.txt)":
            with open(fileName, "w") as f:
                f.write(self.textEdit.toPlainText())
        elif filetype == "Html Files (*.html)":
            with open(fileName, "w") as f:
                f.write(self.textEdit.toHtml())

    def setup_toolBar(self):
        fileToolbar = self.addToolBar("File")  # 添加工具条；可依次添加多个工具条
        fileToolbar.addActions((self.fileOpenAction, self.fileSaveAsAction, self.separator))  # 添加动作
        tb_label1 = QLabel("选择什么东东")
        self.cb = QComboBox()
        self.cb.addItems(("红", "绿", "蓝"))
        fileToolbar.addWidget(tb_label1)  # 工具条添加部件
        fileToolbar.addWidget(self.cb)  # 工具条添加部件
        # ......

    def setup_dockWidget(self):
        # 设置停靠窗口
        self.logDockWidget = QDockWidget("log", self)
        self.logDockWidget.setAllowedAreas(Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea)
        self.listWidget = QListWidget()
        self.logDockWidget.setWidget(self.listWidget)
        self.addDockWidget(Qt.RightDockWidgetArea, self.logDockWidget)  # 添加停靠窗口

    def setup_statusBar(self):
        # 配置状态栏
        self.dateLabel = QLabel()
        self.dateLabel.setFrameStyle(QFrame.StyledPanel | QFrame.Sunken)
        self.dateLabel.setText(QDate.currentDate().toString())

        self.timeLabel = QLabel()
        self.timeLabel.setFrameStyle(QFrame.StyledPanel | QFrame.Sunken)
        self.timeLabel.setText(QTime.currentTime().toString())

        self.statusBar().addPermanentWidget(self.dateLabel)
        self.statusBar().addPermanentWidget(self.timeLabel)

        datetime = QDateTime.currentDateTime().toString()
        self.statusBar().showMessage(datetime, 3000)  # 状态栏在3000ms内显示信息
        self.statusBar().showMessage("ready")  # 状态栏显示信息

        timer = QTimer(self)  # 创建计时器#self
        timer.timeout.connect(self.updateBySecond)  # 计时器超时信号接到用于更新界面的槽
        timer.start(1000)  # 每1000ms发射超时信号

    def updateBySecond(self):
        self.timeLabel.setText(QTime.currentTime().toString())
        self.dateLabel.setText(QDate.currentDate().toString())


if __name__ == '__main__':
    app = QApplication(sys.argv)
    mw = MainWindow()
    mw.show()
    sys.exit(app.exec_())

#本文分享自微信公众号 - Python

 ======================

import sys
from PyQt5.QtCore import Qt, pyqtSignal
from PyQt5.Qt import QRegExp, QRegExpValidator
from PyQt5.QtWidgets import *


# 非模态对话框("Apply"型更新),自定义信号，数据验证，正则表达式，掩码

class NumberFormatDlg(QDialog):
    changed = pyqtSignal()  # 自定义信号

    def __init__(self, format_, parent=None):
        super().__init__(parent)

        thousandsLabel = QLabel("&Thousands seprator")

        self.thousandsEdit = QLineEdit(format_["thousandsseparator"])
        self.thousandsEdit.setMaxLength(1)

        # 正则表达式
        punctuationRe = QRegExp(r"[ ,;:.]")  # 只能为中括号内的某个字符，还可以为空

        # 设定验证方式为正则表达式，不合规的字符输入不进去。预防式验证
        self.thousandsEdit.setValidator(QRegExpValidator(punctuationRe, self))

        thousandsLabel.setBuddy(self.thousandsEdit)

        decimalMarkerLabel = QLabel("Decimal &marker")
        self.decimalMarkerEdit = QLineEdit(format_["decimalmarker"])
        self.decimalMarkerEdit.setMaxLength(1)
        self.decimalMarkerEdit.setValidator(QRegExpValidator(punctuationRe, self))
        self.decimalMarkerEdit.setInputMask("X")  # 设定掩码

        decimalMarkerLabel.setBuddy(self.decimalMarkerEdit)

        decimalPlacesLabel = QLabel("&Decimal places")

        self.decimalPlacesSpinBox = QSpinBox()
        self.decimalPlacesSpinBox.setRange(0, 6)
        self.decimalPlacesSpinBox.setValue(format_["decimalplaces"])

        decimalPlacesLabel.setBuddy(self.decimalPlacesSpinBox)

        self.redNegativesCheckBox = QCheckBox("&Red negative numbers")
        self.redNegativesCheckBox.setChecked(format_["rednegatives"])

        buttonBox = QDialogButtonBox(QDialogButtonBox.Apply | QDialogButtonBox.Close)

        buttonBox.button(QDialogButtonBox.Apply).clicked.connect(self.apply)
        buttonBox.rejected.connect(self.reject)

        grid = QGridLayout()
        grid.addWidget(thousandsLabel, 0, 0)
        grid.addWidget(self.thousandsEdit, 0, 1)
        grid.addWidget(decimalMarkerLabel, 1, 0)
        grid.addWidget(self.decimalMarkerEdit, 1, 1)
        grid.addWidget(decimalPlacesLabel, 2, 0)
        grid.addWidget(self.decimalPlacesSpinBox, 2, 1)
        grid.addWidget(self.redNegativesCheckBox, 3, 0, 1, 2)
        grid.addWidget(buttonBox, 4, 0, 1, 2)
        self.setLayout(grid)

        self.setWindowTitle("数字格式设置（非模态）")

        self.format = format_

    def apply(self):
        thousands = self.thousandsEdit.text()
        decimal = self.decimalMarkerEdit.text()

        # 提交后验证 #交叉验证
        if thousands == decimal:
            QMessageBox.warning(self, "格式错误", "千位分隔符和小数点符不能相同")
            self.thousandsEdit.selectAll()
            self.thousandsEdit.setFocus()
            return
        if decimal == '':
            QMessageBox.warning(self, "格式错误", "小数点符不能为空")
            self.decimalMarkerEdit.selectAll()
            self.decimalMarkerEdit.setFocus()
            return

        self.format["thousandsseparator"] = thousands
        self.format["decimalmarker"] = decimal
        self.format["decimalplaces"] = self.decimalPlacesSpinBox.value()
        self.format["rednegatives"] = self.redNegativesCheckBox.isChecked()

        self.changed.emit()  # 发射自定义信号


class MainDialog(QDialog):
    def __init__(self, parent=None):
        super(MainDialog, self).__init__(parent)
        format_ = dict(thousandsseparator=",", decimalmarker=".", decimalplaces=3, rednegatives=True)
        self.dialog = NumberFormatDlg(format_)

        button = QPushButton("click here", self)
        button.clicked.connect(self.dialog.show)


app = QApplication(sys.argv)
font = MainDialog()
font.show()
app.exec_()

 ==========================

鼠标操作

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QLabel
from PyQt5.QtGui import QCursor
from PyQt5.QtCore import Qt


class Demo(QWidget):

    def __init__(self):
        super(Demo, self).__init__()
        self.label = QLabel('Hello World', self)
        self.label1 = QLabel('喂  世界', self)
        self.label1.move(0, 30)
        self.label2 = QLabel('鼠标位置', self)
        self.resize(500, 300)
        self.label.resize(200, 20)
        self.label1.resize(200, 20)
        self.label2.resize(400, 20)
        self.label2.move(0, 60)
        self.label3 = QLabel('鼠标位置', self)
        self.label3.resize(400, 20)
        self.label3.move(0, 90)

        self.setMouseTracking(True)  # 设置鼠标移动跟踪是否有效
        '''
        设置为True时，只要鼠标在窗口内移动时mouseMoveEvent事件就能捕获
        设置为False时（默认），只有鼠标键按下并在窗口内移动时mouseMoveEvent事件才能捕获
        注意只能是QWidget，如果是QMainwindow，则无效
        self.hasMouseTracking()返回设置的状态
        '''

    def mousePressEvent(self, event):  # 鼠标键按下时调用(任意一个键,按一下调一次)，这些方法是许多控件自带的，这里来自于QWidget。
        self.label.setText('鼠标键按下了')
        n = event.button()  # 用来判断是哪个鼠标健触发了事件【返回值：0  1  2  4】
        '''
        QtCore.Qt.NoButton - 0 - 没有按下鼠标键
        QtCore.Qt.LeftButton -1 -按下鼠标左键
        QtCore.Qt.RightButton -2 -按下鼠标右键
        QtCore.Qt.Mion 或 QtCore.Qt.MiddleButton -4 -按下鼠标中键
        '''
        nn = event.buttons()  # 返回前面所列枚举值的组合，用于判断同时按下了哪些键【不知怎么判断】  <PyQt5.QtCore.Qt.MouseButtons object at 0x0000003326982F98>

    def mouseReleaseEvent(self, event):  #鼠标键释放时调用
        # #参数1：鼠标的作用对象；参数2：鼠标事件对象，用来保存鼠标数据
        self.label.setText('鼠标键放开了')

    def mouseMoveEvent(self, event):  # 鼠标移动事件
        ret = self.hasMouseTracking()  #返回鼠标MouseTracking的状态
        # self.label1.setText('鼠标移动了:%s' % ret)
        x = event.x()  # 返回鼠标相对于窗口的x轴坐标
        y = event.y()  # 返回鼠标相对于窗口的y轴坐标
        # self.label2.setText('鼠标x坐标：%s  ,鼠标y坐标：%s' % (x, y))
        xy = event.pos()  #返回鼠标坐标 ，QPoint(463, 0) 相对于控件  【用xy.x()  xy.y()提取值】
        s=event.localPos()  #返回鼠标坐标  相对于控件   QPointF(2.0, 2.0)

        s = self.mapToGlobal(xy)  # 将窗口坐标转换成屏幕坐标.属于QWidget类的方法；参数类型QPoint
        self.label3.setText('鼠标x坐标：%s  ,鼠标y坐标：%s' % (xy.x(), xy.y()))
        xy1 = event.globalPos()  # 返回鼠标相对于屏幕的坐标。PyQt5.QtCore.QPoint(1096, 37)【用xy1.x()  xy1.y()提取值】
        s1 = self.mapFromGlobal(xy1)  #将屏幕坐标转换成窗口坐标.属于QWidget类的方法；参数类型QPoint
        # mapToParent(QPoint) - 将窗口坐标转换成父窗口坐标。如果没有父窗口，则相当于mapToGlobal (QPoint)
        # mapFromParent(QPoint) - 将父窗口坐标转换成窗口坐标。如果没有父窗口，则相当于mapFromGlobal(QPoint)
        # mapTo (QWidget, QPoint) - 将窗口坐标转换成 QWidget父窗口坐标
        px = event.globalX()  # 返回相对于屏幕的x坐标
        py = event.globalY()  # 返回相对于屏幕的y坐标
        s = event.windowPos()  # 相对于窗口的坐标(保留一位小数)，PyQt5.QtCore.QPointF(481.0, 1.0)【用s.x()  s.y()提取值】
        p = event.screenPos()  # 相对于屏幕的坐标(保留一位小数).PyQt5.QtCore.QPointF(476.0, 49.0)【用p.x()  p.y()提取值】
        t = event.timestamp()  # 返回事件发生的时间。【以程序运行开始计时，以毫秒为单位】

    def mouseDoubleClickEvent(self, event):  # 鼠标双击时调用
        self.label1.setText('双击了鼠标')
        '''双击时的事件顺序如下:
MouseButtonPress
MouseButtonRelease
MouseButtonDblClick
MouseButtonPress
MouseButtonRelease
QApplicaption类的setDoubleClickInterval( )方法可设置双击的时间间隔；doubleClickInterval( )方法返回双击的时间间隔。'''

    def enterEvent(self, event):  # 鼠标移进时调用
        print('鼠标移进窗口了')
        self.setCursor(Qt.CrossCursor)  # 设置鼠标形状。
        # #需要from PyQt5.QtGui import QCursor,from PyQt5.QtCore import Qt
        #鼠标形状对照图见下方
        # self.unsetCursor()   #鼠标恢复系统默认

    def leaveEvent(self, event):  # 鼠标移出时调用
        print('鼠标移出窗口了')

    def wheelEvent(self, event):  # 滚轮滚动时调用。event是一个QWheelEvent对象
        angle = event.angleDelta()  # 返回滚轮转过的数值，单位为1/8度.PyQt5.QtCore.QPoint(0, 120)
        angle = angle / 8  # 除以8之后单位为度。PyQt5.QtCore.QPoint(0, 15)   【向前滚是正数，向后滚是负数  用angle.y()取值】
        ang = event.pixelDelta()  # 返回滚轮转过的像素值  【不知为何  没有值】
        # print(event.x(),event.y())    #返回鼠标相对于窗口的坐标
        w = event.pos()  # 返回相对于控件的当前鼠标位置.PyQt5.QtCore.QPoint(260, 173)
        w1 = event.posF()  # 返回相对于控件的当前鼠标位置.PyQt5.QtCore.QPointF(302.0, 108.0)
        # 坐标函数与上面相同


if __name__ == '__main__':
    app = QApplication(sys.argv)
    demo = Demo()
    demo.show()
    sys.exit(app.exec())