如何在 python 中从 pyqt4 升级到 pyqt5

Question

我想将此代码从 pyqt4 升级或转换为 pyqt5，因为此代码与最新的 pyqt5 不兼容。

所以有人可以告诉我我可以在此代码中对运行在 pyqt5 中进行哪些重大更改。

import sys
from PyQt4.QtCore import Qt
from PyQt4.QtCore import QRectF
from PyQt4.QtWidgets import QApplication
from PyQt4.QtGui import QColor
from PyQt4.QtGui import QFont
from PyQt4.QtGui import QPainter
from PyQt4.QtGui import QPixmap
from PyQt4.QtGui import QTextOption
from PyQt4.QtGui import QToolTip
from PyQt4.QtGui import QWidget

这是此代码的所有导入库

class AreaSelector(QWidget):

    def __init__(self, parent=None):

        QWidget.__init__(self, None, Qt.FramelessWindowHint)
        self.setAttribute(Qt.WA_TranslucentBackground)
        self.setAttribute(Qt.WA_DeleteOnClose)
        self.setWindowState(Qt.WindowFullScreen)
        self.setAutoFillBackground(False)

        self.parent = parent
        self.start_x = 0
        self.start_y = 0
        self.end_x = 0
        self.end_y = 0
        self.current_x = 0
        self.current_y = 0

    def showEvent(self, event):

        self.bg = QPixmap.grabWindow(QApplication.desktop().winId())
        self.screen_geometry = QApplication.desktop().screenGeometry(self)

    def mousePressEvent(self, event):

        self.start_x = event.globalX()
        self.start_y = event.globalY()

    def mouseReleaseEvent(self, event):

        self.end_x = event.globalX()
        self.end_y = event.globalY()

请在此处查看完整代码full code

Answer 1

将 PyQt4 代码转换为 PyQt5 并非易事：

PyQt4 和 PyQt5 分别是 Qt4 和 Qt5 的包装器，因此两者都受到那个转换的变化的影响，其中一个转换是 Qt4 的 QtGui 子模块被分为 QtGui 和 QtWidgets 子模块-Qt5的模块。
一些 classes 和方法已被弃用，因此您必须找到等效的（如果存在）。

在这种情况下，两种情况都会发生，第一种情况的解决方案很简单：您必须查看 Qt 文档并检查它属于哪个子模块，例如 QToolTip，在顶部是 table:

并且 QT += widgets 表示它属于 QtWidgets 子模块的部分被观察到。

但是第二种情况稍微复杂一些，因为它涉及寻找可能在同一 class 中或可能不同的等价物，在这种情况下，它发生在 QPixmap.grabWindow() 方法中，它是弃用（see here 了解更多信息）。进行搜索后，您可以将该代码替换为 QApplication.primaryScreen().grabWindow(0).

综合以上所有，翻译为：

import sys
from PyQt5.QtCore import QRectF, Qt
from PyQt5.QtGui import QColor, QFont, QPainter, QPixmap, QTextOption, QScreen
from PyQt5.QtWidgets import QApplication, QToolTip, QWidget


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

        QWidget.__init__(self, None, Qt.FramelessWindowHint)
        self.setAttribute(Qt.WA_TranslucentBackground)
        self.setAttribute(Qt.WA_DeleteOnClose)
        self.setWindowState(Qt.WindowFullScreen)
        self.setAutoFillBackground(False)

        self.parent = parent
        self.start_x = 0
        self.start_y = 0
        self.end_x = 0
        self.end_y = 0
        self.current_x = 0
        self.current_y = 0

    def showEvent(self, event):
        self.bg = QApplication.primaryScreen().grabWindow(0)
        self.screen_geometry = QApplication.primaryScreen().geometry()

    def mousePressEvent(self, event):

        self.start_x = event.globalX()
        self.start_y = event.globalY()

    def mouseReleaseEvent(self, event):

        self.end_x = event.globalX()
        self.end_y = event.globalY()

    def mouseMoveEvent(self, event):

        self.current_x = event.globalX()
        self.current_y = event.globalY()
        self.repaint()

        text = "Start: %sx%s \nEnd: %sx%s" % (
            self.start_x,
            self.start_y,
            self.current_x,
            self.current_y,
        )
        QToolTip.showText(event.pos(), text)

    def keyPressEvent(self, event):
        if event.key() == Qt.Key_Return:
            self._acceptSelection()
        elif event.key() == Qt.Key_Escape:
            self.close()

    def _acceptSelection(self):

        if self.parent is not None:
            self.parent.areaSelectEvent(
                self.start_x, self.start_y, self.end_x, self.end_y
            )
        self.close()

    def paintEvent(self, event):

        painter = QPainter()
        painter.begin(self)

        painter.fillRect(self.screen_geometry, QColor(10, 10, 10, 125))

        self._paint_selection(painter)
        self._paint_usage_text(painter)
        painter.end()

    def _paint_usage_text(self, painter):

        font = QFont("Helvetica [Cronyx]", 26, QFont.Bold)
        painter.setFont(font)
        painter.setPen(QColor(255, 255, 255, 255))

        screen_width = self.screen_geometry.width()
        text_width = 800
        text_start_x = screen_width / 2 - text_width / 2

        screen_height = self.screen_geometry.height()
        text_height = 200
        text_start_y = screen_height / 2 - text_height / 2

        textoption = QTextOption(Qt.AlignCenter)
        textbox = QRectF(text_start_x, text_start_y, text_width, text_height)
        painter.drawText(
            textbox,
            "Click & Drag to select an area\n" "ENTER to confirm or ESC to cancel",
            textoption,
        )
        painter.drawRoundedRect(textbox, 20, 20)

    def _paint_selection(self, painter):
        """Draws the current user selection"""
        rectangle = QRectF()

        if self.start_x > self.current_x:
            rectangle.setLeft(self.current_x)
            rectangle.setRight(self.start_x)

        else:
            rectangle.setLeft(self.start_x)
            rectangle.setRight(self.current_x)

        if self.start_y > self.current_y:
            rectangle.setTop(self.current_y)
            rectangle.setBottom(self.start_y)

        else:
            rectangle.setTop(self.start_y)
            rectangle.setBottom(self.current_y)

        painter.drawPixmap(rectangle, self.bg, rectangle)
        painter.drawRect(rectangle)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    main = AreaSelector()
    main.show()
    sys.exit(app.exec_())

如何在 python 中从 pyqt4 升级到 pyqt5

how to upgrade from pyqt4 to pyqt5 in python

python

pyqt4

pyqt5