PyQt5初级教程--PyQt5中的部件II[9/13]

想用PyQt5写GUI,但是网上的PyQt5资源太少了,找到一个英文的,翻译一下,和学习PyQt5的同学共勉!

(本系列中所有代码在windows7 64位[]/Python 3.4.3 32bit/PyQt GPL v5.5 for Python v3.4 (x32)/eric6-6.0.8下测试通过.)

原本地址:http://zetcode.com/gui/pyqt5/

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在此我们会继续介绍PyQt5的部件.我们会介绍QPixmap、QLineEdit、QSplitter和QComboBox.

QPixmap

一个QPixmap是一个用于处理图像的部件.它更适合在屏幕上显示图片.在下面的例子中,我们会用QPixmap来在窗口上显示一个图片.

#!/usr/bin/python3# -*- coding: utf-8 -*-"""ZetCode PyQt5 tutorial In this example, we dispay an imageon the window. author: Jan Bodnarwebsite: zetcode.com last edited: January 2015"""import sysfrom PyQt5.QtWidgets import (QWidget, QHBoxLayout,     QLabel, QApplication)from PyQt5.QtGui import QPixmapclass Example(QWidget):        def __init__(self):        super().__init__()                self.initUI()                    def initUI(self):              hbox = QHBoxLayout(self)        pixmap = QPixmap("redrock.png")        lbl = QLabel(self)        lbl.setPixmap(pixmap)        hbox.addWidget(lbl)        self.setLayout(hbox)                self.move(300, 200)        self.setWindowTitle('Red Rock')        self.show()                        if __name__ == '__main__':        app = QApplication(sys.argv)    ex = Example()    sys.exit(app.exec_())

在上面的例子中,我们在窗口上显示了一张图片.

pixmap = QPixmap("redrock.png")

我们创建一个QPixmap对象,他用文件名作为参数.

lbl = QLabel(self)lbl.setPixmap(pixmap)

我们把Pixmap放到QLabel部件里.

QLineEdit

一个QLineEdit是一个允许输入和编辑一行纯文件的部件.部件支持撤销和重做、剪切和剪贴、拖拽功能.

#!/usr/bin/python3# -*- coding: utf-8 -*-"""ZetCode PyQt5 tutorial This example shows text which is entered in a QLineEditin a QLabel widget. author: Jan Bodnarwebsite: zetcode.com last edited: January 2015"""import sysfrom PyQt5.QtWidgets import (QWidget, QLabel,     QLineEdit, QApplication)class Example(QWidget):        def __init__(self):        super().__init__()                self.initUI()                    def initUI(self):              self.lbl = QLabel(self)        qle = QLineEdit(self)                qle.move(60, 100)        self.lbl.move(60, 40)        qle.textChanged[str].connect(self.onChanged)                self.setGeometry(300, 300, 280, 170)        self.setWindowTitle('QLineEdit')        self.show()                    def onChanged(self, text):                self.lbl.setText(text)        self.lbl.adjustSize()                        if __name__ == '__main__':        app = QApplication(sys.argv)    ex = Example()    sys.exit(app.exec_())

这个例子我们显示了一个行编辑器和一个标签.我们在行编辑器里输入的文本会立刻在标签中显示.

qle = QLineEdit(self)

创建一个QLineEdit部件.

qle.textChanged[str].connect(self.onChanged)

如果在行编辑器里的文本有变动,我们就调用onChanged()方法.

def onChanged(self, text):        self.lbl.setText(text)    self.lbl.adjustSize()

在onChanged()方法里,我们设置被输入的文本到标签部件.我们通过调用adjustSize()方法来调整标签的大小到文本的长度.

图片:行编辑器

QSplitter

一个QSplitter可以让用户通过拖拽子部件的边界来控制子部件的大小.在下面的例子中,我们显示三个QFrame部件用两个分割器调整.

#!/usr/bin/python3# -*- coding: utf-8 -*-"""ZetCode PyQt5 tutorial This example showshow to use QSplitter widget. author: Jan Bodnarwebsite: zetcode.com last edited: January 2015"""import sysfrom PyQt5.QtWidgets import (QWidget, QHBoxLayout, QFrame,     QSplitter, QStyleFactory, QApplication)from PyQt5.QtCore import Qtclass Example(QWidget):        def __init__(self):        super().__init__()                self.initUI()                    def initUI(self):              hbox = QHBoxLayout(self)        topleft = QFrame(self)        topleft.setFrameShape(QFrame.StyledPanel)         topright = QFrame(self)        topright.setFrameShape(QFrame.StyledPanel)        bottom = QFrame(self)        bottom.setFrameShape(QFrame.StyledPanel)        splitter1 = QSplitter(Qt.Horizontal)        splitter1.addWidget(topleft)        splitter1.addWidget(topright)        splitter2 = QSplitter(Qt.Vertical)        splitter2.addWidget(splitter1)        splitter2.addWidget(bottom)        hbox.addWidget(splitter2)        self.setLayout(hbox)                self.setGeometry(300, 300, 300, 200)        self.setWindowTitle('QSplitter')        self.show()                    def onChanged(self, text):                self.lbl.setText(text)        self.lbl.adjustSize()                        if __name__ == '__main__':        app = QApplication(sys.argv)    ex = Example()    sys.exit(app.exec_()) 

在这个例子中,有三个框架和两个分割器.请注意,在某些主题下,分割器可能并不会很友好的显示.

topleft = QFrame(self)topleft.setFrameShape(QFrame.StyledPanel)

我们用一个经典的框架以便可以看清QFrame部件的边界.

splitter1 = QSplitter(Qt.Horizontal)splitter1.addWidget(topleft)splitter1.addWidget(topright)

我们创建一个QSplitter部件,把两个框架加到它里面.

splitter2 = QSplitter(Qt.Vertical)splitter2.addWidget(splitter1)

我们还可以把一个分割器加到另一个分割器部件里.

图片:分割器

QComboBox

QComboBox是一个允许用户从一个选项列表里选择的部件.

#!/usr/bin/python3# -*- coding: utf-8 -*-"""ZetCode PyQt5 tutorial This example shows how to use a QComboBox widget. author: Jan Bodnarwebsite: zetcode.com last edited: January 2015"""import sysfrom PyQt5.QtWidgets import (QWidget, QLabel,     QComboBox, QApplication)class Example(QWidget):        def __init__(self):        super().__init__()                self.initUI()                    def initUI(self):              self.lbl = QLabel("Ubuntu", self)        combo = QComboBox(self)        combo.addItem("Ubuntu")        combo.addItem("Mandriva")        combo.addItem("Fedora")        combo.addItem("Arch")        combo.addItem("Gentoo")        combo.move(50, 50)        self.lbl.move(50, 150)        combo.activated[str].connect(self.onActivated)                         self.setGeometry(300, 300, 300, 200)        self.setWindowTitle('QComboBox')        self.show()                    def onActivated(self, text):              self.lbl.setText(text)        self.lbl.adjustSize()                          if __name__ == '__main__':        app = QApplication(sys.argv)    ex = Example()    sys.exit(app.exec_())

例子显示了一个QComboBox和一个标签.下拉列表框是一个有着5个选项的列表.它们是Linux发行版的名字.标签部件显示了从下拉列表框选择的选项.

combo = QComboBox(self)combo.addItem("Ubuntu")combo.addItem("Mandriva")combo.addItem("Fedora")combo.addItem("Arch")combo.addItem("Gentoo")

我们创建一个有着5个选项的QComboBox部件.

combo.activated[str].connect(self.onActivated) 

基于选择,我们调用onActivated()方法.

def onActivated(self, text):      self.lbl.setText(text)    self.lbl.adjustSize() 

在方法里,我们设置被选择的文本到标签部件.我们会调整标签的大小.

图片:下拉列表框