Question

我希望我的窗口和QGraphicsScene是透明的，由QSlider控制。

我试图在这里和那里寻找一些答案，但这主要是将背景色设置为0：

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

或类似的话：

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

它可以做到这一点，但是我想制作一个可以控制透明度的滑块，但是我看不到如何使用上面的命令来做到这一点。

有人可以给我一些建议怎么做吗？谢谢

我将在下面附加测试代码（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，以更轻松地将不透明度从完全不透明更改为完全透明。

Answer 2

尝试一下：

#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_())

如何设置窗口及其图形场景透明（使用滑块）并仅使QPushButton可见

2 个答案: