如何设置窗口和它的图形场景透明（使用滑块）和只留下QPushButton visib

Question

我希望我的窗口和它的qgraphicscene是透明的，这是由QSlider控制的。你知道吗

我试着到处寻找答案，但主要是将背景色设置为0：

self.setStyleSheet("background-color:rgba(0, 0, 0, 0);")

或者像这样：

self.setWindowFlags(Qt.FramelessWindowHint) 
self.setAttribute(Qt.WA_TranslucentBackground)

它的工作，但我想使滑块，将控制透明度的水平，我不知道我如何才能做到上面的命令。你知道吗

谁能告诉我怎么做吗？谢谢

我将在下面附上我的测试代码（我希望能够控制所有内容的透明度，但不要触摸滑块和按钮）：

from PySide2.QtGui import QBrush, QColor
from PySide2.QtCore import QSize, Qt
from PySide2.QtWidgets import QDialog, QVBoxLayout, QGraphicsView, QGraphicsScene, QFrame, QSizePolicy, QApplication, QSlider, QPushButton

class MainWindow(QDialog):
    def __init__(self):
        QDialog.__init__(self)
        self.mainLayout = QVBoxLayout()
        self.graphicsWidget = MainGraphicsWidget()
        self.window = 'transp_test'
        self.title = 'transparent UI'
        self.size = (1000, 650)
        self.create()


    def create(self, **kwargs):
        self.setWindowTitle(self.title)
        self.resize(QSize(*self.size))
        self.setLayout(self.mainLayout)
        self.mainLayout.addWidget(self.graphicsWidget)


class MainGraphicsWidget(QGraphicsView):
    def __init__(self, parent=None):
        super(MainGraphicsWidget, self).__init__(parent)
        self._scene = QGraphicsScene(backgroundBrush = Qt.gray)
        self.setScene(self._scene)

        self.transpSlider = QSlider()
        self.transpSlider.setRange(0,100)

        self.mainButton = QPushButton('I want it to be "Test" button')

        self._scene.addWidget(self.mainButton)
        self._scene.addWidget(self.transpSlider)
        self.transpSlider.move(300, 100)

        self.setTransformationAnchor(QGraphicsView.AnchorUnderMouse)
        self.setResizeAnchor(QGraphicsView.AnchorUnderMouse)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.setBackgroundBrush(QBrush(QColor(30, 30, 30)))
        self.setFrameShape(QFrame.NoFrame)
        self.setSizePolicy(QSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding))

if __name__ == '__main__':
    import sys

    app = QApplication(sys.argv)
    window = MainWindow()
    window.setGeometry(600, 300, 600, 600)
    window.show()
    sys.exit(app.exec_())

Answer 1

这里有一个方法。你知道吗

class MainWindow(QDialog):
    def __init__(self):
        QDialog.__init__(self)
        # these two lines are needed to get a transparent background in windows
        self.setWindowFlags(Qt.FramelessWindowHint)
        self.setAttribute(Qt.WA_TranslucentBackground)

        # rest of class definition unchanged


class MainGraphicsWidget(QGraphicsView):
    def __init__(self, parent=None):
        super(MainGraphicsWidget, self).__init__(parent)
        # set transparent background color for the widget itself
        self.setStyleSheet("background-color: #00000000")
        self._scene = QGraphicsScene()
        self.setScene(self._scene)

        # create of slider and connect to slot for changing opacity.
        self.transpSlider = QSlider()
        self.transpSlider.setStyleSheet('background-color: #00000000')
        self.transpSlider.setRange(0,255)
        self.transpSlider.valueChanged.connect(self.set_opacity)
        self.transpSlider.setValue(255)

        # rest of __init__ unchanged

    def set_opacity(self, value):
        brush = self.backgroundBrush()
        color = brush.color()
        color.setAlpha(value)
        brush.setColor(color)
        self.setBackgroundBrush(color)

请注意，我已将滑块的范围更改为0-255，以便更容易地将不透明度从完全不透明更改为完全透明。你知道吗