python - QSplitter、QWidget 调整大小、setSizes()、setStretchFactor() 和 sizeHint() - 如何让它们一起工作？

Question

我正在努力研究如何使标题中的所有内容在特定情况下协同工作。我在这里使用 PyQt5，但可以随意使用常规 C++ Qt 进行响应，因为我可以很容易地翻译。

我正在尝试使用以下内容制作 UI：

主要形式（继承自QWidget，也可以使用QMainWindow）
主窗体应包含一个QSplitter垂直方向QTextEdit，顶部包含一个 a 并包含一个自定义类（继承自QLabel）以显示占据其余空间的图像。
顶部的QTextEdit应该默认为大约 3 行文本高，但这应该可以通过QSplitter.
自定义类应该在给定可用空间的情况下将图像调整为尽可能大，同时保持纵横比。

当然，棘手的部分是根据用户的显示器大小以及表单的移动方式来正确调整所有内容的大小。我需要它在小至约 1,000 像素宽度和可能大至 3,000+ 像素宽度的屏幕上运行。

这是我到目前为止所拥有的：

# QSplitter3.py

import cv2
import numpy as np

from PyQt5.QtWidgets import QApplication, QWidget, QHBoxLayout, QVBoxLayout, QLabel, QGridLayout, QSizePolicy, \
    QFrame, QTabWidget, QTextEdit, QSplitter
from PyQt5.QtGui import QImage, QPixmap, QPainter
from PyQt5.Qt import Qt
from PyQt5.Qt import QPoint


def main():
    app = QApplication([])

    screenSize = app.primaryScreen().size()
    print('screenSize = ' + str(screenSize.width()) + ', ' + str(screenSize.height()))

    mainForm = MainForm(screenSize)
    mainForm.show()
    app.exec()
# end function

class MainForm(QWidget):

    def __init__(self, screenSize):
        super().__init__()

        # set the title and size of the Qt QWidget window
        self.setWindowTitle('Qt Window')
        self.setGeometry(screenSize.width() * 0.2, screenSize.height() * 0.2,
                         screenSize.width() * 0.5 , screenSize.height() * 0.7)

        # declare a QTextEdit to show user messages at the top, set the font size, height, and read only property
        self.txtUserMessages = QTextEdit()
        self.setFontSize(self.txtUserMessages, 14)
        self.txtUserMessages.setReadOnly(True)

        # make the min height of the text box about 2 lines of text high
        self.txtUserMessages.setMinimumHeight(self.getTextEditHeightForNLines(self.txtUserMessages, 2))

        # populate the user messages text box with some example text
        self.txtUserMessages.append('message 1')
        self.txtUserMessages.append('message 2')
        self.txtUserMessages.append('message 3')
        self.txtUserMessages.append('stuff here')
        self.txtUserMessages.append('bla bla bla')
        self.txtUserMessages.append('asdasdsadds')

        # instantiate the custom ImageWidget class below to show the image
        self.imageWidget = ImageWidget()
        self.imageWidget.setMargin(0)
        self.imageWidget.setContentsMargins(0, 0, 0, 0)
        self.imageWidget.setScaledContents(True)
        self.imageWidget.setSizePolicy(QSizePolicy.Ignored, QSizePolicy.Ignored)
        self.imageWidget.setAlignment(Qt.AlignCenter)

        # declare the splitter, then add the user message text box and tab widget
        self.splitter = QSplitter(Qt.Vertical)
        self.splitter.addWidget(self.txtUserMessages)
        self.splitter.addWidget(self.imageWidget)

        defaultTextEditHeight = self.getTextEditHeightForNLines(self.txtUserMessages, 3)
        print('defaultTextEditHeight = ' + str(defaultTextEditHeight))
        # How can I use defaultTextEditHeight height here, but still allow resizing ??

        # I really don't like this line, the 1000 is a guess and check that may only work with one screen size !!!
        self.splitter.setSizes([defaultTextEditHeight, 1000])

        # Should setStretchFactor be used here ??  This does not seem to work
        # self.splitter.setStretchFactor(0, 0)
        # self.splitter.setStretchFactor(1, 1)

        # What about sizeHint() ??  Should that be used here, and if so, how ??

        # set the main form's layout to the QGridLayout
        self.gridLayout = QGridLayout()
        self.gridLayout.addWidget(self.splitter)

        self.setLayout(self.gridLayout)

        # open the two images in OpenCV format
        self.openCvImage = cv2.imread('image.jpg')

        if self.openCvImage is None:
            print('error opening image')
            return
        # end if

        # convert the OpenCV image to QImage
        self.qtImage = openCvImageToQImage(self.openCvImage)

        # show the QImage on the ImageWidget
        self.imageWidget.setPixmap(QPixmap.fromImage(self.qtImage))

    # end function

    def setFontSize(self, widget, fontSize):
        font = widget.font()
        font.setPointSize(fontSize)
        widget.setFont(font)
    # end function

    def getTextEditHeightForNLines(self, textEdit, numLines):
        fontMetrics = textEdit.fontMetrics()
        rowHeight = fontMetrics.lineSpacing()
        rowHeight = rowHeight * 1.21
        textEditHeight = int(numLines * rowHeight)
        return textEditHeight
    # end function

# end class

def openCvImageToQImage(openCvImage):
    # get the height, width, and num channels of the OpenCV image, then compute the byte value
    height, width, numChannels = openCvImage.shape
    byteValue = numChannels * width

    # make the QImage from the OpenCV image
    qtImage = QImage(openCvImage.data, width, height, byteValue, QImage.Format_RGB888).rgbSwapped()

    return qtImage
# end function

class ImageWidget(QLabel):
    def __init__(self):
        super(QLabel, self).__init__()
    # end function

    def setPixmap(self, pixmap):
        self.pixmap = pixmap
    # end function

    def paintEvent(self, event):
        size = self.size()
        painter = QPainter(self)
        point = QPoint(0, 0)
        scaledPixmap = self.pixmap.scaled(size, Qt.KeepAspectRatio, transformMode=Qt.SmoothTransformation)
        point.setX((size.width() - scaledPixmap.width()) / 2)
        point.setY((size.height() - scaledPixmap.height()) / 2)
        painter.drawPixmap(point, scaledPixmap)
    # end function
# end class

if __name__ == '__main__':
    main()

目前我正在一个 2560x1440 屏幕上进行测试，并且1000输入了魔法，它适用于这个屏幕尺寸，但我真的不喜欢硬编码的1000. 我怀疑我遗漏的代码区域是这部分：

# declare the splitter, then add the user message text box and tab widget
        self.splitter = QSplitter(Qt.Vertical)
        self.splitter.addWidget(self.txtUserMessages)
        self.splitter.addWidget(self.imageWidget)

        defaultTextEditHeight = self.getTextEditHeightForNLines(self.txtUserMessages, 3)
        print('defaultTextEditHeight = ' + str(defaultTextEditHeight))
        # How can I use defaultTextEditHeight height here, but still allow resizing ??

        # I really don't like this line, the 1000 is a guess and check that may only work with one screen size !!!
        self.splitter.setSizes([defaultTextEditHeight, 1000])

        # Should setStretchFactor be used here ??  This does not seem to work
        # self.splitter.setStretchFactor(0, 0)
        # self.splitter.setStretchFactor(1, 1)

        # What about sizeHint() ??  Should that be used here, and if so, how ??

        # set the main form's layout to the QGridLayout
        self.gridLayout = QGridLayout()
        self.gridLayout.addWidget(self.splitter)

使用硬编码的 1000 在这个特定的屏幕上它工作得很好：

重申（希望更清楚）我试图能够删除硬编码的 1000 和命令 Qt，如下所示：

最初使表格占据屏幕的大约 2/3
最初使文本框大约 3 行文本高（最少 2 行文本高）
允许用户使用 QSplitter 随时无限制地调整文本框和图像的大小
调整表单大小（或最小化或最大化）时，根据用户在调整大小时的大小按比例调整文本框和图像的大小

我已经尝试了标题中提到的所有东西的组合，到目前为止在这篇文章中，但我无法获得这个功能，除了硬编码的 1000 可能不适用于不同的屏幕尺寸.

如何删除硬编码的 1000 并修改上述内容以实现预期功能？

score 1 · Accepted Answer

在我的解决方案中，我不会考虑 opencv 的部分，因为它增加了不必要的复杂性。

解决方案是使用setStretchFactor()方法，在这种情况下覆盖设置初始大小的sizeHint()方法和QTextEdit设置最小高度的 setMinimumHeight() 方法。为了显示图像，我使用 aQGraphicsView而不是，QLabel因为逻辑更容易。

from PyQt5 import QtCore, QtGui, QtWidgets


class TextEdit(QtWidgets.QTextEdit):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setReadOnly(True)
        font = self.font()
        font.setPointSize(14)
        self.setFont(font)
        self.setMinimumHeight(self.heightForLines(2))

    def heightForLines(self, n):
        return (
            n * self.fontMetrics().lineSpacing() + 2 * self.document().documentMargin()
        )

    def showEvent(self, event):
        self.verticalScrollBar().setValue(self.verticalScrollBar().minimum())

    def sizeHint(self):
        s = super().sizeHint()
        s.setHeight(self.heightForLines(3))
        return s


class GraphicsView(QtWidgets.QGraphicsView):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setFrameShape(QtWidgets.QFrame.NoFrame)
        self.setBackgroundBrush(self.palette().brush(QtGui.QPalette.Window))
        scene = QtWidgets.QGraphicsScene(self)
        self.setScene(scene)

        self._pixmap_item = QtWidgets.QGraphicsPixmapItem()
        scene.addItem(self._pixmap_item)

    def setPixmap(self, pixmap):
        self._pixmap_item.setPixmap(pixmap)

    def resizeEvent(self, event):
        self.fitInView(self._pixmap_item, QtCore.Qt.KeepAspectRatio)
        self.centerOn(self._pixmap_item)
        super().resizeEvent(event)


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.textedit = TextEdit()
        for i in range(10):
            self.textedit.append("Message {}".format(i))

        self.graphicsview = GraphicsView()
        self.graphicsview.setPixmap(QtGui.QPixmap("image.jpg"))

        splitter = QtWidgets.QSplitter(QtCore.Qt.Vertical)

        splitter.addWidget(self.textedit)
        splitter.addWidget(self.graphicsview)

        splitter.setStretchFactor(1, 1)

        lay = QtWidgets.QGridLayout(self)
        lay.addWidget(splitter)

        screenSize = QtWidgets.QApplication.primaryScreen().size()
        self.setGeometry(
            screenSize.width() * 0.2,
            screenSize.height() * 0.2,
            screenSize.width() * 0.5,
            screenSize.height() * 0.7,
        )


def main():
    app = QtWidgets.QApplication([])
    w = Widget()
    w.resize(640, 480)
    w.show()
    app.exec_()


if __name__ == "__main__":
    main()

python - QSplitter、QWidget 调整大小、setSizes()、setStretchFactor() 和 sizeHint() - 如何让它们一起工作？

1 回答 1

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