PyQt5中的鼠标悬停事件

Question

我想知道鼠标悬停在标签上时的位置。我读了this，但我的问题不同。我需要抓住鼠标的位置，因为它悬停在我的标签上而不点击，所以，mouseMoveEvent没有帮助

这是我的密码：

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.WindowGUI()
        self.level = "Image Not Loaded Yet"
        self.mouseIsClicked = False
        self.top = 90
        self.left = 90
        self.height = 1800
        self.width = 1800
        self.setGeometry(self.top, self.left, self.height, self.width)
        self.setWindowTitle("Manual Contact Andgle")
        self.setMouseTracking(True)
        mainWidget = QWidget(self)
        self.setCentralWidget(mainWidget)
        mainWidget.setLayout(self.finalVbox)

        self.show()

    def WindowGUI(self):
        self.finalVbox = QVBoxLayout()  # Final Layout
        self.mainHBox = QHBoxLayout()  # Hbox for picLable and Buttons
        self.mainVBox = QVBoxLayout()  # VBox for two Groupboxes
        self.lineVBox = QVBoxLayout()  # VBox For Line Drawing Buttons
        self.fileVBox = QVBoxLayout()  # VBox for file Loading and Saving Buttons
        self.lineGroupbox = QGroupBox("Drawing")  # GroupBox For Line Drawing Buttons
        self.fileGroupbox = QGroupBox("File")  # GroupBox for File Loading and Saving Buttons
        self.picLable = Label(self)  # Lable For showing the Image
        self.piclable_pixmap = QPixmap("loadImage.png")  # Setting Pixmap
        self.picLable.setPixmap(self.piclable_pixmap)  # setting pixmap to piclable
    def mouseMoveEvent(self, QMouseEvent):
        print(QMouseEvent.pos())

Answer 1

如果要在不按下小部件的情况下检测鼠标位置，则必须启用捕鼠器，以便在按下或不按下鼠标时调用mouseMoveEvent。如果要验证鼠标是否未按下，则必须使用buttons（）方法：

import sys

from PyQt5 import QtWidgets


class Label(QtWidgets.QLabel):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setMouseTracking(True)

    def mouseMoveEvent(self, event):
        if not event.buttons():
            print(event.pos())
        super().mouseMoveEvent(event)


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    w = Label()
    w.resize(640, 480)
    w.show()
    sys.exit(app.exec_())

更新：

如果子项不使用鼠标事件，则会将鼠标事件从子项传播到父项，也就是说，如果子项使用鼠标事件，则父项无法使用鼠标事件。因此QLabel正在使用该事件，因此不会通知窗口，因此在这种情况下应使用eventFilter：

import sys

from PyQt5.QtCore import pyqtSignal, pyqtSlot, QEvent, QObject, QPoint
from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import QApplication, QLabel, QMainWindow


class HoverTracker(QObject):
    positionChanged = pyqtSignal(QPoint)

    def __init__(self, widget):
        super().__init__(widget)
        self._widget = widget
        self.widget.setMouseTracking(True)
        self.widget.installEventFilter(self)

    @property
    def widget(self):
        return self._widget

    def eventFilter(self, obj, event):
        if obj is self.widget and event.type() == QEvent.MouseMove:
            self.positionChanged.emit(event.pos())
        return super().eventFilter(obj, event)


class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Manual Contact Andgle")

        self.picLable = QLabel(self)
        self.picLable.setPixmap(QPixmap("loadImage.png"))

        hover_tracker = HoverTracker(self.picLable)
        hover_tracker.positionChanged.connect(self.on_position_changed)

    @pyqtSlot(QPoint)
    def on_position_changed(self, p):
        print(p)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    w = MyWindow()
    w.resize(640, 480)
    w.show()
    sys.exit(app.exec_())

Answer 2

您可以使用enterEvent

每次鼠标悬停在小部件上时，都会调用Enter事件。使用event.pos()可以获得鼠标坐标

self.label.enterEvent = lambda event: print(event.pos())