Pyqt 基础功能

总结Pyqt的基础知识

1. Pyqt  设置禁止最大化及禁止拖拽窗口大小

        # PyQT禁止窗口最大化按钮：
        self.setWindowFlags(QtCore.Qt.WindowMinimizeButtonHint)
        # PyQT禁止调整窗口大小:
        self.setFixedSize(self.width(), self.height())

1.1 修改窗体大小

self.resize(500, 400)

2. 当按下Esc退出

重载keyPressEvent

    def keyPressEvent(self, event):
        if event.key() ==QtCore.Qt.Key_Escape:
            self.close()

3.去掉标题栏

self.setWindowFlags(Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint)

self.setWindowFlags(Qt.CustomizeWindowHint)  # 有透明边框

4.触发信号槽

内部方法 triggered()    clicked()

执行：  quit()

QtGui.QWidget.connect(self.ui_qr.pushButtonOk, QtCore.SIGNAL('clicked()'), self.generateQr) 
self.ui_qr.pushButtonOk.clicked.connect(self.generateQr)

5.弹框消息

消息类型： information   ,    warning     ,     question      , about 

OK = QtGui.QMessageBox.question(self, (u'提示'),(u'滚动轴点击'),QtGui.QMessageBox.Yes , QtGui.QMessageBox.No)

6.支持窗口拖动

重载鼠标事件方法

    def mousePressEvent(self, event):
        if event.button()==Qt.LeftButton:
            self.m_drag=True
            self.m_DragPosition=event.globalPos()-self.pos()
            event.accept()

    def mouseMoveEvent(self, QMouseEvent):
        if QMouseEvent.buttons() and Qt.LeftButton:
            self.move(QMouseEvent.globalPos()-self.m_DragPosition)
            QMouseEvent.accept()

    def mouseReleaseEvent(self, QMouseEvent):
        self.m_drag=False

7.设置全局编码

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

        reload(sys)
        sys.setdefaultencoding("utf-8")

 8.设置标题、Icon

label.setPixmap(QtGui.QPixmap(filename))
self.setWindowTitle('Pyqt ComboBox')
self.setWindowIcon(QtGui.QIcon('../Document/images/QQ.png'))

9.设置button   lineEdit 等字体 

self.lineEdit.setFont(QFont("SimSun", 18, QFont.Bold))     # 宋体  ，   18号字体，    粗体

10.退出后，后台继续保持进程

app.setQuitOnLastWindowClosed(True)  #true 关闭， false 开启后台

11.显示在最前端

self.setWindowFlags(QtCore.Qt.WindowStaysOnTopHint)

12.窗体透明度

self.setWindowOpacity(0.5)   # 1表示100%显示， 0.5 透明度50% 

13.只显示关闭按钮

self.setWindowFlags(Qt.CustomizeWindowHint| Qt.WindowCloseButtonHint )

 14.隐藏状态栏

self.setWindowFlags(QtCore.Qt.Tool )

15.自定义发射事件信号

from PyQt5.QtWidgets import *
from PyQt5 import QtCore

class MyForm(QMainWindow):
    _signal = QtCore.pyqtSignal(str)  # 定义信号,定义参数为str类型  str、int、list、object、float、tuple、dict

    def __init__(self):
        super().__init__()
        button = QPushButton('Button ')
        button.clicked.connect(self.on_button)

        self._signal.connect(self.mySignal)  # 将信号连接到函数mySignal
        layout = QHBoxLayout()
        layout.addWidget(button)
        main_frame = QWidget()
        main_frame.setLayout(layout)
        self.setCentralWidget(main_frame)

    def on_button(self):
        self._signal.emit('hello,你好')  # 需要之时emit 

    def mySignal(self, string):
        print(string)


if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    form = MyForm()
    form.show()
    app.exec_()

16.信号和槽传递额外参数

from PyQt5.QtWidgets import *
# 使用lambda传递按钮数字给槽     by: http://blog.csdn.net/a359680405/article/details/45246605
class MyForm(QMainWindow):
    def __init__(self):
        super().__init__()
        button1 = QPushButton('Button 1')
        button2 = QPushButton('Button 2')
        button1.clicked.connect(lambda: self.on_button('1'))
        button2.clicked.connect(lambda: self.on_button('2'))

        layout = QHBoxLayout()
        layout.addWidget(button1)
        layout.addWidget(button2)

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

    def on_button(self, n):
        print('Button {0} clicked'.format(n))

if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    form = MyForm()
    form.show()
    app.exec_()