PyQt5菜单栏，背景和拖动主窗口

Question

我正在尝试使用Python在PyQt5中制作图像查看器。到目前为止，我目前拥有所需的功能，这是根据我的意愿来设计GUI样式的问题。

看起来几乎是我想要的。我努力获得那种透明的背景，但是设法通过将windowflags设置为FramelesswindowHint。不幸的是，现在我没有菜单栏可以关闭应用程序并拖动窗口。我想，如果我想以适合我的背景的方式对其进行样式设置，就必须制作自己的酒吧，这很好，添加一个X按钮以关闭窗口应该不是太大的问题。

我的问题是，如何制作才能拖动窗口？我可以制作一个矩形小部件，并使用按钮将其放置在顶部，但是如果用户单击并拖动整个窗口，如何移动整个窗口？我知道周围也有类似的问题，但是我不确定如何在PyQt5中的对象上执行单击和拖动功能，而且它们似乎使用了不同的布局策略，因此我感到困惑。

这是我的代码：

from PyQt5 import QtCore, QtGui, QtWidgets
import os


class Ui_MainWindow(object):
    def __init__(self):
        cwd = r"C:\Users\chees\PycharmProjects\PYQT5GUI\images"
        self.imagelist = []
        self.imagepaths = []
        self.imagecount = 0

        for a, b, c in os.walk(cwd):
            self.imagelist = c
            for i in c:
                self.imagepaths.append(a + "\\" + i)
            print(self.imagepaths)


    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.setWindowModality(QtCore.Qt.NonModal)
        MainWindow.resize(661, 580)

        MainWindow.setAttribute(QtCore.Qt.WA_TranslucentBackground)
        MainWindow.setWindowFlags(QtCore.Qt.FramelessWindowHint)


        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")

        self.b = QtWidgets.QWidget(self.centralwidget)
        self.b.setGeometry(QtCore.QRect(0, 0, MainWindow.width(), MainWindow.height()))
        self.b.setStyleSheet("background-color: rgba(0, 0, 0, 70%); border:1px; border-radius:25px;")




        self.imageviewer = QtWidgets.QLabel(self.centralwidget)
        self.imageviewer.setGeometry(QtCore.QRect(170, 60, 351, 321))



        self.imageviewer.setText("")
        self.imageviewer.setPixmap(QtGui.QPixmap("images/IMG1.jpg"))
        self.imageviewer.setScaledContents(True)
        self.imageviewer.setObjectName("imageviewer")

        self.backward_button = QtWidgets.QPushButton(self.centralwidget)
        self.backward_button.setGeometry(QtCore.QRect(50, 471, 120, 50))
        self.backward_button.setObjectName("backward_button")
        self.backward_button.clicked.connect(self.backward)

        self.forward_button = QtWidgets.QPushButton(self.centralwidget)
        self.forward_button.setGeometry(QtCore.QRect(510, 470, 120, 50))
        self.forward_button.setObjectName("forward_button")
        self.forward_button.clicked.connect(self.forward)

        MainWindow.setCentralWidget(self.centralwidget)


        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        self.statusbar.setStyleSheet("background-color: rgba(255,255,255, 40%)")

        MainWindow.setStatusBar(self.statusbar)


        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

        self.changesize()



    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.backward_button.setText(_translate("MainWindow", "<<"))
        self.forward_button.setText(_translate("MainWindow", ">>"))

    def changesize(self):
        self.imageviewer.adjustSize()
        if self.imageviewer.width() < 500:
            MainWindow.resize(500, self.imageviewer.height() + 200)
            self.b.resize(500, self.imageviewer.height() + 200)

            self.imageviewer.move((500-self.imageviewer.width())//2, 55)
        else:
            MainWindow.resize((self.imageviewer.width() + self.imageviewer.width() // 8), (self.imageviewer.height() + 200))
            self.b.resize((self.imageviewer.width() + self.imageviewer.width() // 8),
                              (self.imageviewer.height() + 200))
            self.imageviewer.move(self.imageviewer.width() // 16, 55)
        self.forward_button.move(MainWindow.width()-150,MainWindow.height()-80)
        self.backward_button.move(30, MainWindow.height() - 80)
        self.statusbar.showMessage(self.imagepaths[self.imagecount])


    def flipmode(self):
        self.imageviewer.setPixmap(QtGui.QPixmap("images\\" + self.imagelist[self.imagecount]))
        self.changesize()
        print(self.imageviewer.height(), self.imageviewer.width())

    def forward(self):
        self.imagecount += 1
        if self.imagecount == len(self.imagelist):
            self.imagecount = 0
        self.flipmode()


    def backward(self):
        self.imagecount -= 1
        if self.imagecount < 0:
            self.imagecount = len(self.imagelist)-1
        self.flipmode()



if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()

    ui.setupUi(MainWindow)
    MainWindow.show()

    print(ui.imagelist)
    sys.exit(app.exec_())

Answer 1

请勿修改Qt Designer生成的代码，而是创建另一个继承的类从适当的窗口小部件中，并使用初始类来填充它。

拖动窗口的一种方法可能看起来像这样：

    self._old_pos = None

def mousePressEvent(self, event):
    if event.button() == QtCore.Qt.LeftButton:
        self._old_pos = event.pos()

def mouseReleaseEvent(self, event):
    if event.button() == QtCore.Qt.LeftButton:
        self._old_pos = None

def mouseMoveEvent(self, event):
    if not self._old_pos:
        return
    delta = event.pos() - self._old_pos
    self.move(self.pos() + delta)

---

from PyQt5 import QtCore, QtGui, QtWidgets
import os


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.setWindowModality(QtCore.Qt.NonModal)
        MainWindow.resize(661, 580)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.b = QtWidgets.QWidget(self.centralwidget)
        self.b.setGeometry(QtCore.QRect(0, 0, MainWindow.width(), MainWindow.height()))
        self.b.setStyleSheet("background-color: rgba(0, 0, 0, 70%); border:1px; border-radius:25px;")

        self.imageviewer = QtWidgets.QLabel(self.centralwidget)
        self.imageviewer.setGeometry(QtCore.QRect(170, 60, 351, 321))
        self.imageviewer.setText("")
        self.imageviewer.setPixmap(QtGui.QPixmap("images/IMG1.jpg"))
        self.imageviewer.setScaledContents(True)
        self.imageviewer.setObjectName("imageviewer")
        self.backward_button = QtWidgets.QPushButton(self.centralwidget)
        self.backward_button.setGeometry(QtCore.QRect(50, 471, 120, 50))
        self.backward_button.setObjectName("backward_button")
        self.backward_button.clicked.connect(self.backward)
        self.forward_button = QtWidgets.QPushButton(self.centralwidget)
        self.forward_button.setGeometry(QtCore.QRect(510, 470, 120, 50))
        self.forward_button.setObjectName("forward_button")
        self.forward_button.clicked.connect(self.forward)

        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        self.statusbar.setStyleSheet("background-color: rgba(255,255,255, 40%)")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.backward_button.setText(_translate("MainWindow", "<<"))
        self.forward_button.setText(_translate("MainWindow", ">>"))


class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self):
        super().__init__()

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

#        cwd = r"C:\Users\chees\PycharmProjects\PYQT5GUI\images"
        cwd = "D:/_Qt/__Qt/images"

        self.imagelist = []
        self.imagepaths = []
        self.imagecount = 0

        for a, b, c in os.walk(cwd):
            self.imagelist = c
            for i in c:
                self.imagepaths.append(a + "\\" + i)
            #print(self.imagepaths)

        self.changesize()

#++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

        self._old_pos = None

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            self._old_pos = event.pos()

    def mouseReleaseEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            self._old_pos = None

    def mouseMoveEvent(self, event):
        if not self._old_pos:
            return
        delta = event.pos() - self._old_pos
        self.move(self.pos() + delta)
# ++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^        


    def changesize(self):
        self.imageviewer.adjustSize()
        if self.imageviewer.width() < 500:
            self.resize(500, self.imageviewer.height() + 200)
            self.b.resize(500, self.imageviewer.height() + 200)

            self.imageviewer.move((500-self.imageviewer.width())//2, 55)
        else:
            self.resize((self.imageviewer.width() + self.imageviewer.width() // 8), (self.imageviewer.height() + 200))
            self.b.resize((self.imageviewer.width() + self.imageviewer.width() // 8),
                              (self.imageviewer.height() + 200))
            self.imageviewer.move(self.imageviewer.width() // 16, 55)
        self.forward_button.move(self.width()-150, self.height()-80)
        self.backward_button.move(30, self.height() - 80)
        self.statusbar.showMessage(self.imagepaths[self.imagecount])


    def flipmode(self):
        self.imageviewer.setPixmap(QtGui.QPixmap("images\\" + self.imagelist[self.imagecount]))
        self.changesize()
#        print(self.imageviewer.height(), self.imageviewer.width())

    def forward(self):
        self.imagecount += 1
        if self.imagecount == len(self.imagelist):
            self.imagecount = 0
        self.flipmode()


    def backward(self):
        self.imagecount -= 1
        if self.imagecount < 0:
            self.imagecount = len(self.imagelist)-1
        self.flipmode()        


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
#    MainWindow = QtWidgets.QMainWindow()
#    ui = Ui_MainWindow()
#    ui.setupUi(MainWindow)
#    MainWindow.show()
    w = MainWindow()
    w.show()
#    print(ui.imagelist)
    sys.exit(app.exec_())