PyQt5 Note

安装

  • 对于Python 2
pip install python-qt5
  • 对于Python 3
pip install pysip
pip install PyQt5
pip install PyQt5-tools

实例代码

  • 在QTextEdit中, 修改Enter和Return键是默认处理方式

因为Enter和Return键是默认处理的, 并且在QTextEdit中按下回车键, 主窗口event是不会捕获到这个事件的, 所以无法在主窗口中用keyPressEvent来修改；我们可以在主窗口中重新定义eventFilter函数, 并对textEdit 调用installEventFilter来注册事件处理函数

class SuperMaster(QWidget):
    def __init__(self, parent=None):
        
        ...
        ...
        ...

        self.ui.textEdit_2.installEventFilter(self)

        ...
        ...
        ...

    def eventFilter(self, watched, event):
        if watched == self.ui.textEdit_2:
            if event.type() == QtCore.QEvent.KeyPress:
                key_event = QtGui.QKeyEvent(event)
                if key_event.key() in (QtCore.Qt.Key_Enter, QtCore.Qt.Key_Return):
                    print('Enter')
                    if key_event.modifiers() == QtCore.Qt.ControlModifier:
                        print('Ctrl + Enter')
                    elif key_event.modifiers() == QtCore.Qt.AltModifier:
                        print('Alt + Enter')
                    elif key_event.modifiers() == QtCore.Qt.ShiftModifier:
                        print('Shift + Enter')

        return QWidget.eventFilter(self, watched, event)

重新实现QTextEdit类中的keyPressEvent函数来忽略对应键的操作, 并用这个类来创建QTextEdit对象

from PyQt5 import QtCore, QtGui, QtWidgets

class MyTextEdit(QtWidgets.QTextEdit):
    def __init__(self, parent):
        super(MyTextEdit, self).__init__(parent)
    
    def keyPressEvent(self, event):
        # 没有按回车，默认处理
        if event.key() not in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
            QtWidgets.QTextEdit.keyPressEvent(self,event)
        else:
            # Alt + 回车和Shift + 回车默认处理; 只按回车、回车+Ctrl或者回车+其他的都不处理
            if event.modifiers() == QtCore.Qt.AltModifier or event.modifiers() == QtCore.Qt.ShiftModifier:
                QtWidgets.QTextEdit.keyPressEvent(self,event)
  • 获取QTextEdit中光标所在行的内容; 前提是不能修改前面回车键的默认操作, 否则会获取所有行的内容
self.ui.textEdit_2.textCursor().block().text()
  • 获取QTextEdit中光标所在行的行号; 前提是不能修改前面回车键的默认操作, 否则一直为0
self.ui.textEdit_2.textCursor().blockNumber()
  • 界面设置代码
# 设置窗口透明度
Ui_MainWindow.setWindowOpacity(0.9)

# 隐藏边框
Ui_MainWindow.setWindowFlag(QtCore.Qt.FramelessWindowHint)

# 设置背景色
pe = QPalette()
Ui_MainWindow.setAutoFillBackground(True)
pe.setColor(QPalette.Window,Qt.lightGray)
Ui_MainWindow.setPalette(pe)

# 设置图标
Ui_MainWindow.setWindowIcon(QIcon('Amg.jpg'))

# 设置QSS样式
self.pushbutton_close.setStyleSheet('''QPushButton{background:#F76677;border-radius:15px;} QPushButton:hover{background:red;}''')

# 字体居中
self.text_label.setAlignment(Qt.AlignCenter)
self.label.setAlignment(Qt.AlignCenter)

ImportError: unable to find Qt5Core.dll on PATH

  • 现象：

最近在一台电脑上安装了最新的PyQt5和PyQt5-tools包, 用Pyinstaller打包PyQt5写的应用程序后, 应用程序打开失败 然后我用不带-w的参数重新打包, 并在CMD中用call来调用打包好的exe, 则会出现以下错误

ImportError: unable to find Qt5Core.dll on PATH

  • 解决方法:

在源代码目录新建Python文件: fix_qt_import_error.py, 文件内容如下:

# Fix qt import error
# Include this file before import PyQt5 

import os
import sys
import logging


def _append_run_path():
    if getattr(sys, 'frozen', False):
        pathlist = []

        # If the application is run as a bundle, the pyInstaller bootloader
        # extends the sys module by a flag frozen=True and sets the app
        # path into variable _MEIPASS'.
        pathlist.append(sys._MEIPASS)

        # the application exe path
        _main_app_path = os.path.dirname(sys.executable)
        pathlist.append(_main_app_path)

        # append to system path enviroment
        os.environ["PATH"] += os.pathsep + os.pathsep.join(pathlist)

    logging.error("current PATH: %s", os.environ['PATH'])


_append_run_path()

然后在应用程序中用import PyQt5之前import fix_qt_import_error; 重新打包后即能正常运行

QtAwesome界面图标

  • 安装方法:
pip install QtAwesome

https://pypi.org/project/QtAwesome/ https://fontawesome.com/v4.7.0/icons/

在label中加载图片时报以下错误

self.INBOX_LABEL_LED.setPixmap(QtGui.QPixmap("icons/blue-led.png"))

Cocos2dx:libpng warning: iCCP: known incorrect sRGB profile

解决方法:

https://www.cnblogs.com/Fallever/p/6843235.html

参考: https://stackoverflow.com/questions/56949297/how-to-fix-importerror-unable-to-find-qt5core-dll-on-path-after-pyinstaller-b