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 image
on the window. 

author: Jan Bodnar
website: zetcode.com 
last edited: January 2015
"""

import sys
from PyQt5.QtWidgets import (QWidget, QHBoxLayout, 
    QLabel, QApplication)
from PyQt5.QtGui import QPixmap


class 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 QLineEdit
in a QLabel widget.
 
author: Jan Bodnar
website: zetcode.com 
last edited: January 2015
"""

import sys
from 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 shows
how to use QSplitter widget.
 
author: Jan Bodnar
website: zetcode.com 
last edited: January 2015
"""

import sys
from PyQt5.QtWidgets import (QWidget, QHBoxLayout, QFrame, 
    QSplitter, QStyleFactory, QApplication)
from PyQt5.QtCore import Qt


class 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 Bodnar
website: zetcode.com 
last edited: January 2015
"""

import sys
from 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