如何设置 window 和它的 graphicScene 透明（使用滑块）并且只留下 QPushButton 可见

Question

我希望我的 window 和它的 QGraphicsScene 是透明的，它由 QSlider 控制。

我试着在这里和那里寻找一些答案，但主要是将背景颜色设置为 0 :

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

或类似的：

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

它的作用是什么，但我想制作控制透明度级别的滑块，但我不知道如何使用上面的命令来实现。

有人可以给我一些建议吗？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

这是一种方法。

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，以便更轻松地将不透明度从完全不透明更改为完全透明。

Answer 2

试一试：

#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

from PyQt5 import QtCore, QtWidgets, QtGui
from PyQt5.QtGui import QBrush, QColor
from PyQt5.QtCore import QSize, Qt
from PyQt5.QtWidgets import (QDialog, QVBoxLayout, QGraphicsView, QGraphicsScene, 
                             QFrame, QSizePolicy, QApplication, QSlider, QPushButton)


class MainGraphicsWidget(QGraphicsView):
    def __init__(self, parent=None):
        super(MainGraphicsWidget, self).__init__(parent)

        self._scene = QGraphicsScene() 
        self.setScene(self._scene)
        self.transpSlider = QtWidgets.QSlider(
            QtCore.Qt.Horizontal,
            minimum=10,
            maximum=100,
            value=100,
            valueChanged=self.onValueChanged,
        )
        self.mainButton = QPushButton('I want it to be "Test" button \n QUIT')
        self.mainButton.resize(150, 150)
        self.mainButton.clicked.connect(parent.close)

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

        self.setTransformationAnchor(QGraphicsView.AnchorUnderMouse)
        self.setResizeAnchor(QGraphicsView.AnchorUnderMouse)
        c = QColor(220, 30, 30)
        c.setAlphaF(1) 
        self.setBackgroundBrush(QBrush(c))
        self.setFrameShape(QFrame.NoFrame)
        self.setSizePolicy(QSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding))

    @QtCore.pyqtSlot(int)
    def onValueChanged(self, value):
        c = QColor(220, 30, 30)
        c.setAlphaF(value * 0.01) 
        self.setBackgroundBrush(QBrush(c))
        window.setWindowOpacity(value * 0.03)   
        self.setStyleSheet("MainGraphicsWidget {{background-color: rgba(0, 215, 55, {});}}".format(value))  


class MainWindow(QDialog):
    def __init__(self):
        super().__init__()
        self.setAttribute(Qt.WA_NoSystemBackground, False)      
        self.setStyleSheet("MainWindow {background-color: rgba(0, 215, 55, 70);}")   

        self.graphicsWidget = MainGraphicsWidget(self)  

        self.window = 'transp_test'
        self.title  = 'transparent UI'
        self.size   = (1000, 650)
        self.setWindowTitle(self.title)
        self.resize(QSize(*self.size))

        self.mainLayout = QVBoxLayout()
        self.setLayout(self.mainLayout)       
        self.mainLayout.addWidget(self.graphicsWidget)


if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    window = MainWindow()
    window.setGeometry(600, 100, 600, 600)
    window.show()
    sys.exit(app.exec_())

如何设置 window 和它的 graphicScene 透明（使用滑块）并且只留下 QPushButton 可见

How to set window and it's graphicScene transparent(using slider) and leave only QPushButton visible

python

pyside2