pyqt5 - display widget on top of QVideoWidget with QMediaPlayer

问题

What I want to achieve is to have a button or a widget to be displayed on top of a QVideoWidget. Following this example of a sample video player, I tried to add a button on top of the QVideoWidget with the following code

self.button= QPushButton(videoWidget)

The button is displayed properly just as it should, but once I start playing the video file I open, the button disappears. I noticed if I hover my mouse over the location of the button, it briefly reappears before it disappears again, which makes me think that the button is being hidden by the QMediaPlayer which is being rerendered on top of everything for every frame.

How can I keep the button on top while the video is playing?

回答1:

That is a known problem since the drawing of the video is not directly done by Qt but OpenGL, a solution is to have a widget where the QVideoWidget is placed and in that widget place the button:

QWidget(container)
 ├── QVideoWidget
 └── QPushButton

Code:

# !/usr/bin/env python

import sys

from PyQt5 import QtCore, QtGui, QtWidgets, QtMultimedia, QtMultimediaWidgets


class VideoWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(VideoWindow, self).__init__(parent)
        self.setWindowTitle("PyQt Video Player Widget Example - pythonprogramminglanguage.com")

        self.mediaPlayer = QtMultimedia.QMediaPlayer(None, QtMultimedia.QMediaPlayer.VideoSurface)

        videoWidget = QtMultimediaWidgets.QVideoWidget()

        container = QtWidgets.QWidget()
        lay = QtWidgets.QVBoxLayout(container)
        lay.setContentsMargins(0, 0, 0, 0)
        lay.addWidget(videoWidget)

        buttonn = QtWidgets.QPushButton("button", container)


        self.playButton = QtWidgets.QPushButton()
        self.playButton.setEnabled(False)
        self.playButton.setIcon(self.style().standardIcon(QtWidgets.QStyle.SP_MediaPlay))
        self.playButton.clicked.connect(self.play)

        self.positionSlider = QtWidgets.QSlider(QtCore.Qt.Horizontal)
        self.positionSlider.setRange(0, 0)
        self.positionSlider.sliderMoved.connect(self.setPosition)

        self.errorLabel = QtWidgets.QLabel()
        self.errorLabel.setSizePolicy(QtWidgets.QSizePolicy.Preferred,
                                      QtWidgets.QSizePolicy.Maximum)

        # Create new action
        openAction = QtWidgets.QAction(QtGui.QIcon('open.png'), '&Open', self)
        openAction.setShortcut('Ctrl+O')
        openAction.setStatusTip('Open movie')
        openAction.triggered.connect(self.openFile)

        # Create exit action
        exitAction = QtWidgets.QAction(QtGui.QIcon('exit.png'), '&Exit', self)
        exitAction.setShortcut('Ctrl+Q')
        exitAction.setStatusTip('Exit application')
        exitAction.triggered.connect(self.close)

        # Create menu bar and add action
        menuBar = self.menuBar()
        fileMenu = menuBar.addMenu('&File')
        # fileMenu.addAction(newAction)
        fileMenu.addAction(openAction)
        fileMenu.addAction(exitAction)

        # Create a widget for window contents
        wid = QtWidgets.QWidget(self)
        self.setCentralWidget(wid)

        # Create layouts to place inside widget
        controlLayout = QtWidgets.QHBoxLayout()
        controlLayout.setContentsMargins(0, 0, 0, 0)
        controlLayout.addWidget(self.playButton)
        controlLayout.addWidget(self.positionSlider)

        layout = QtWidgets.QVBoxLayout()
        layout.addWidget(container)
        layout.addLayout(controlLayout)
        layout.addWidget(self.errorLabel)

        # Set widget to contain window contents
        wid.setLayout(layout)

        self.mediaPlayer.setVideoOutput(videoWidget)
        self.mediaPlayer.stateChanged.connect(self.mediaStateChanged)
        self.mediaPlayer.positionChanged.connect(self.positionChanged)
        self.mediaPlayer.durationChanged.connect(self.durationChanged)
        self.mediaPlayer.error.connect(self.handleError)

    def openFile(self):
        fileName, _ = QtWidgets.QFileDialog.getOpenFileName(self, "Open Movie",
                                                  QtCore.QDir.homePath())

        if fileName:
            self.mediaPlayer.setMedia(
                QtMultimedia.QMediaContent(QtCore.QUrl.fromLocalFile(fileName)))
            self.playButton.setEnabled(True)

    def play(self):
        if self.mediaPlayer.state() == QtMultimedia.QMediaPlayer.PlayingState:
            self.mediaPlayer.pause()
        else:
            self.mediaPlayer.play()

    def mediaStateChanged(self, state):
        if self.mediaPlayer.state() == QtMultimedia.QMediaPlayer.PlayingState:
            self.playButton.setIcon(
                self.style().standardIcon(QtWidgets.QStyle.SP_MediaPause))
        else:
            self.playButton.setIcon(
                self.style().standardIcon(QtWidgets.QStyle.SP_MediaPlay))

    def positionChanged(self, position):
        self.positionSlider.setValue(position)

    def durationChanged(self, duration):
        self.positionSlider.setRange(0, duration)

    def setPosition(self, position):
        self.mediaPlayer.setPosition(position)

    def handleError(self):
        self.playButton.setEnabled(False)
        self.errorLabel.setText("Error: " + self.mediaPlayer.errorString())


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    player = VideoWindow()
    player.resize(640, 480)
    player.show()
    sys.exit(app.exec_())

Output:

来源：https://stackoverflow.com/questions/51644685/pyqt5-display-widget-on-top-of-qvideowidget-with-qmediaplayer