pyqt：具有透明背景的小部件

Question

I want to draw a transparent-background rectangle in pyqt. The following code meets my need in Mac:

import sys
from PyQt4 import QtGui, QtCore, Qt

class ZoomWidget(QtGui.QWidget):
    def __init__(self):  
        QtGui.QWidget.__init__(self)
        #self.setAttribute(Qt.Qt.WA_NoSystemBackground)
        self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
        self.setAttribute(QtCore.Qt.WA_TranslucentBackground)
        self.setStyleSheet("background-color:transparent;")
        self.setGeometry(100,100,100,100)
        self.show()        

    def paintEvent(self, e=None): 
        qp = QtGui.QPainter()
        qp.begin(self)
        qp.setPen( QtGui.QPen(QtCore.Qt.gray,3,QtCore.Qt.DashDotLine ) )
        qp.drawRect(0,0,self.rect().width()-1, self.rect().height()-1)  
        qp.end()

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    ex = ZoomWidget()
    sys.exit(app.exec_())

However, when I used this code in Linux, it gave me a black-background rectangle. What should I do to give the transparent background to it? Thanks.

Answer 1

have you tried to set parent of ZoomWidget ?

...
def __init__(self, *args, **kwargs):
    QtGui.QWidget.__init__(self, *args, **kwargs)
...
app = QtGui.QApplication(sys.argv)
dial = QtGui.QDialog()
ex = ZoomWidget(parent=dial)
dial.show()
...