Qt4 按钮

Created: September-25, 2018

Qt4 按钮

PyQt4(Qt4) 通过 QPushButton 控件支持按钮。

我们扩展代码以在窗口中心显示一个按钮。

如果悬停，按钮将显示工具提示，按下时将关闭程序。

PyQt4 按钮示例

下面的示例为 PyQt4 窗口添加了一个按钮。

#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
import sys
from PyQt4.QtGui import *
 
# Create an PyQT4 application object.
a = QApplication(sys.argv)
 
# The QWidget widget is the base class of all user interface objects in PyQt4.
w = QWidget()
 
# Set window size.
w.resize(320, 240)
 
# Set window title
w.setWindowTitle("Hello World!")
 
# Add a button
btn = QPushButton('Hello World!', w)
btn.setToolTip('Click to quit!')
btn.clicked.connect(exit)
btn.resize(btn.sizeHint())
btn.move(100, 80)
 
# Show window
w.show()
 
sys.exit(a.exec_())

PyQt4 信号和槽

点击按钮应该做一些事情。为此，你必须使用信号和槽。

如果用户执行诸如单击按钮，在框中键入文本等操作，则窗口控件会发出信号。信号可以与插槽连接，插槽充当接收器并作用于其上。

import sys
from PyQt4.QtCore import pyqtSlot
from PyQt4.QtGui import *
 
# create our window
app = QApplication(sys.argv)
w = QWidget()
w.setWindowTitle('Button click example @pythonspot.com')
 
# Create a button in the window
btn = QPushButton('Click me', w)
 
# Create the actions
@pyqtSlot()
def on_click():
    print('clicked')
 
@pyqtSlot()
def on_press():
    print('pressed')
 
@pyqtSlot()
def on_release():
    print('released')
 
# connect the signals to the slots
btn.clicked.connect(on_click)
btn.pressed.connect(on_press)
btn.released.connect(on_release)
 
# Show the window and run the app
w.show()
app.exec_()