是否可以创建只有外部边框的QMainWindow？

Question

我正在尝试重建一个屏幕记录PyQt应用程序，而ScreenToGIF对我来说是一个很好的演示，它创建了一个只在“中央小部件”中具有边框和记录内容的接口，如下所示：

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具有以下主要职能：

1. 边框存在，可以通过鼠标拖动和调整大小。
2. 内部内容是透明的
3. 鼠标点击可以穿透应用程序，并与其下方的其他应用程序进行交互。

然而，它是在C# (链接：https://github.com/NickeManarin/ScreenToGif)中实现的，我想知道是否有可能在没有学习C#专业知识的情况下制作类似的PyQt应用程序？

将QMainWidgets的背景图像更改为桌面区域没有意义，因为应该记录桌面上的鼠标操作(例如双击打开文件)。鼠标事件可以穿透应用程序(就像Qt.WindowTransparentForInput应用于内部内容？)

Answer 1

您想要实现的目标是设置一个https://doc.qt.io/qt-5/qwidget.html#setMask-1，允许您拥有一个具有特定“形状”的小部件，该小部件不一定是矩形。

主要的困难是理解窗口几何图形是如何工作的，这可能很棘手。

您必须确保窗口“框架”(包括其边距和标题栏-如果有的话)已经计算，然后找出内部矩形，并创建相应的掩码。请注意，在Linux上，这发生在调用了“某一段时间”之后；我认为您在show()上，但是我已经以一种对Linux、MacOS和show()都很好的方式实现了它。如果您确信您的程序将只在Windows上运行，则有关于此的评论。

最后，我只能在Linux、葡萄酒和一个虚拟化的WinXP环境上运行这个程序。它应该在任何系统上都能正常工作，但是，根据我的经验，有一个特定的“化妆品”错误:标题栏不是按照当前的Windows主题绘制的。我认为这是因为无论何时应用掩码，底层的windows系统都不会像通常那样绘制“样式”窗口框架。如果在较新的系统中也出现这种情况，可能会有一个解决办法，但这并不容易，我不能保证它能解决这个问题。

NB：请记住，这种方法永远不会允许您在“抓取矩形”内绘制任何东西(没有阴影，也没有半透明的彩色掩码)；原因是您显然需要实现鼠标与“下方”小部件的交互，并对其进行绘制将需要更改覆盖掩码。

from PyQt5 import QtCore, QtGui, QtWidgets

class VLine(QtWidgets.QFrame):
    # a simple VLine, like the one you get from designer
    def __init__(self):
        super(VLine, self).__init__()
        self.setFrameShape(self.VLine|self.Sunken)


class Grabber(QtWidgets.QWidget):
    dirty = True
    def __init__(self):
        super(Grabber, self).__init__()
        self.setWindowTitle('Screen grabber')
        # ensure that the widget always stays on top, no matter what
        self.setWindowFlags(self.windowFlags() | QtCore.Qt.WindowStaysOnTopHint)

        layout = QtWidgets.QVBoxLayout()
        self.setLayout(layout)
        # limit widget AND layout margins
        layout.setContentsMargins(0, 0, 0, 0)
        self.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)

        # create a "placeholder" widget for the screen grab geometry
        self.grabWidget = QtWidgets.QWidget()
        self.grabWidget.setSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
        layout.addWidget(self.grabWidget)

        # let's add a configuration panel
        self.panel = QtWidgets.QWidget()
        layout.addWidget(self.panel)

        panelLayout = QtWidgets.QHBoxLayout()
        self.panel.setLayout(panelLayout)
        panelLayout.setContentsMargins(0, 0, 0, 0)
        self.setContentsMargins(1, 1, 1, 1)

        self.configButton = QtWidgets.QPushButton(self.style().standardIcon(QtWidgets.QStyle.SP_ComputerIcon), '')
        self.configButton.setFlat(True)
        panelLayout.addWidget(self.configButton)

        panelLayout.addWidget(VLine())

        self.fpsSpinBox = QtWidgets.QSpinBox()
        panelLayout.addWidget(self.fpsSpinBox)
        self.fpsSpinBox.setRange(1, 50)
        self.fpsSpinBox.setValue(15)
        panelLayout.addWidget(QtWidgets.QLabel('fps'))

        panelLayout.addWidget(VLine())

        self.widthLabel = QtWidgets.QLabel()
        panelLayout.addWidget(self.widthLabel)
        self.widthLabel.setFrameShape(QtWidgets.QLabel.StyledPanel|QtWidgets.QLabel.Sunken)

        panelLayout.addWidget(QtWidgets.QLabel('x'))

        self.heightLabel = QtWidgets.QLabel()
        panelLayout.addWidget(self.heightLabel)
        self.heightLabel.setFrameShape(QtWidgets.QLabel.StyledPanel|QtWidgets.QLabel.Sunken)

        panelLayout.addWidget(QtWidgets.QLabel('px'))

        panelLayout.addWidget(VLine())

        self.recButton = QtWidgets.QPushButton('rec')
        panelLayout.addWidget(self.recButton)

        self.playButton = QtWidgets.QPushButton('play')
        panelLayout.addWidget(self.playButton)

        panelLayout.addStretch(1000)

    def updateMask(self):
        # get the *whole* window geometry, including its titlebar and borders
        frameRect = self.frameGeometry()

        # get the grabWidget geometry and remap it to global coordinates
        grabGeometry = self.grabWidget.geometry()
        grabGeometry.moveTopLeft(self.grabWidget.mapToGlobal(QtCore.QPoint(0, 0)))

        # get the actual margins between the grabWidget and the window margins
        left = frameRect.left() - grabGeometry.left()
        top = frameRect.top() - grabGeometry.top()
        right = frameRect.right() - grabGeometry.right()
        bottom = frameRect.bottom() - grabGeometry.bottom()

        # reset the geometries to get "0-point" rectangles for the mask
        frameRect.moveTopLeft(QtCore.QPoint(0, 0))
        grabGeometry.moveTopLeft(QtCore.QPoint(0, 0))

        # create the base mask region, adjusted to the margins between the
        # grabWidget and the window as computed above
        region = QtGui.QRegion(frameRect.adjusted(left, top, right, bottom))
        # "subtract" the grabWidget rectangle to get a mask that only contains
        # the window titlebar, margins and panel
        region -= QtGui.QRegion(grabGeometry)
        self.setMask(region)

        # update the grab size according to grabWidget geometry
        self.widthLabel.setText(str(self.grabWidget.width()))
        self.heightLabel.setText(str(self.grabWidget.height()))

    def resizeEvent(self, event):
        super(Grabber, self).resizeEvent(event)
        # the first resizeEvent is called *before* any first-time showEvent and
        # paintEvent, there's no need to update the mask until then; see below
        if not self.dirty:
            self.updateMask()

    def paintEvent(self, event):
        super(Grabber, self).paintEvent(event)
        # on Linux the frameGeometry is actually updated "sometime" after show()
        # is called; on Windows and MacOS it *should* happen as soon as the first
        # non-spontaneous showEvent is called (programmatically called: showEvent
        # is also called whenever a window is restored after it has been
        # minimized); we can assume that all that has already happened as soon as
        # the first paintEvent is called; before then the window is flagged as
        # "dirty", meaning that there's no need to update its mask yet.
        # Once paintEvent has been called the first time, the geometries should
        # have been already updated, we can mark the geometries "clean" and then
        # actually apply the mask.
        if self.dirty:
            self.updateMask()
            self.dirty = False


if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    grabber = Grabber()
    grabber.show()
    sys.exit(app.exec_())

Answer 2

请尝尝这个

from PyQt5.QtWidgets import QMainWindow, QApplication
from PyQt5.QtCore import Qt
import sys


class MainWindowExample(QMainWindow):
    def __init__(self, parent=None):
        try:
            QMainWindow.__init__(self, parent)
            self.setWindowFlags(Qt.CustomizeWindowHint | Qt.FramelessWindowHint)
            self.setStyleSheet("border: 1px solid rgba(0, 0, 0, 0.15);")
        except Exception as e:
            print(e)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    main_widow = MainWindowExample()
    main_widow.show()
    sys.exit(app.exec_())