PyQt5学习笔记(08)--Widgets II

本文代码来自zetcode.com

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QPixmap

QPixmap是一类用来处理图片的控件，针对在屏幕上显示的图片进行了优化

#!/usr/bin/python3

"""
In this example, we display an image
on the window.
"""

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


class Example(QWidget):

    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        hbox = QHBoxLayout(self)
        pixmap = QPixmap("redrock.jpg")    #  创建QPixmap对象

        lbl = QLabel(self)
        lbl.setPixmap(pixmap)    #  将pixmap放入QLabel控件中

        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_())

如下图：

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QLineEdit

QLineEdit控件允许用户编辑文本，进行撤销、重写、复制、剪切、拖拽等操作。

#!/usr/bin/python3

"""
This example shows text which
is entered in a QLineEdit in
a QLabel widget.
"""

import sys
from PyQt5.QtWidgets import QWidget, QApplication, QLineEdit, QLabel


class Example(QWidget):

    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.lbl = QLabel(self)
        qle = QLineEdit(self)    #  创建QLineEdit对象

        qle.move(60, 100)
        self.lbl.move(60, 40)

        qle.textChanged[str].connect(self.onChanged)    #  当编辑框里的文本改变，我们调用onChanged()方法

        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_())

在onChanged()方法中，我们将输入的文本放入标签控件中，然后调用adjustSize()方法调整标签大小以适应文本长度。

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QSplitter

QSplitter允许用户通过拖拽窗口边界控制子控件的大小

#!/usr/bin/python3

"""
This example shows
how to use QSplitter widget.
"""

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


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

本例中我们有三个框控件和两个分离控件

topleft.setFrameShape(QFrame.SytlePannel)

我们使用QFrame.StylePannel以便看清QFrame控件的边界

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QComboBox

QComboBox控件提供用户选择选项

#!/usr/bin/python3

"""
This example shows how to use
a QComboBox widget.
"""

import sys
from PyQt5.QtWidgets import QWidget, QApplication, QLabel, QComboBox


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_())

经过选择后，我们使用onAcitivated()方法，将选择的条目显示在标签上