PyQt5 QSpinBox – 当鼠标悬停在向上的按钮上时为其添加边框

Python PyQt5 QSpinBox添加鼠标悬停效果攻略

PyQt5是Python下GUI编程框架，借助PyQt5 QSpinBox控件可以实现数字输入框的功能。我们可以添加一些特性来丰富用户体验，例如当鼠标悬停在向上的按钮上时，为其添加边框。这里我们将介绍如何使用PyQt5 QSpinBox实现添加鼠标悬停效果。

QStyle

QStyle是PyQt5的样式类，它包含提供GUI元素的方法以及计算其度量值的方法。QStyle可用于使用样式表、子类化和扩展样式等。我们可以使用QStyle进行自定义控制，例如实现悬停效果。

实现添加鼠标悬停效果的代码

from PyQt5.QtWidgets import QSpinBox, QStyle
from PyQt5.QtCore import QRect

class CustomSpinBox(QSpinBox):
    def setButtonStyleSheet(self, button):
        self.buttonRect = QRect(button.x(), button.y(), button.width(), button.height())
        button.setStyleSheet("background-color: #ffffff; border: 1px solid #d3d3d3;")
        button.installEventFilter(self)

    def eventFilter(self, object, event):
        if object.property("objectName") == "spinBox":
            if event.type() == event.Enter:
                self.style = self.style() if self.style() else QStyleFactory.create("Windows")
                overlay = self.style.generatedIconPixmap(QStyle.SP_ArrowUp, None, None)
                painter = QPainter(overlay)
                painter.setPen(QPen(QColor(233, 233, 233, 255), 3, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
                painter.drawRect(self.buttonRect.x(), self.buttonRect.y(), self.buttonRect.width(), self.buttonRect.height())
                object.setIcon(QIcon(overlay))
            elif event.type() == event.Leave:
                object.setIcon(QIcon())

        return super().eventFilter(object, event)

在上面的代码中，我们创建了一个自定义QSpinBox控件，继承了QSpinBox，重写了setButtonStyleSheet和eventFilter两个方法以实现悬停效果。setButtonStyleSheet方法用于为按钮添加样式并激活事件过滤处理；eventFilter方法则用于判断事件类型是否为进入或离开。当触发进入事件时，我们会利用QStyle类来创建一个图标，并在其上添加一个矩形框做为边框，这个图标将会替代QSpinBox默认显示的箭头图标，从而让整个控件看起来像是发生了变化。

示例

下面我们将分别演示在不同的平台上应用上述方法来实现添加鼠标悬停效果。

Windows平台

from PyQt5.QtWidgets import QSpinBox, QStyleFactory, QApplication
from PyQt5.QtCore import QRect, Qt
from PyQt5.QtGui import QPainter, QPen, QColor, QIcon
import sys

class CustomSpinBox(QSpinBox):
    def setButtonStyleSheet(self, button):
        self.buttonRect = QRect(button.x(), button.y(), button.width(), button.height())
        button.setStyleSheet("background-color: #ffffff; border: 1px solid #d3d3d3;")
        button.installEventFilter(self)

    def eventFilter(self, object, event):
        if object.property("objectName") == "spinBox":
            if event.type() == event.Enter:
                self.style = self.style() if self.style() else QStyleFactory.create("Windows")
                overlay = self.style.generatedIconPixmap(QStyle.SP_ArrowUp, None, None)
                painter = QPainter(overlay)
                painter.setPen(QPen(QColor(233, 233, 233, 255), 3, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
                painter.drawRect(self.buttonRect.x(), self.buttonRect.y(), self.buttonRect.width(), self.buttonRect.height())
                object.setIcon(QIcon(overlay))
            elif event.type() == event.Leave:
                object.setIcon(QIcon())

        return super().eventFilter(object, event)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    win = CustomSpinBox()
    win.show()
    sys.exit(app.exec_())

MacOS平台

from PyQt5.QtWidgets import QSpinBox, QStyle, QApplication
from PyQt5.QtCore import QRect
from PyQt5.QtGui import QPainter, QPen, QColor, QIcon
import sys

class CustomSpinBox(QSpinBox):
    def setButtonStyleSheet(self, button):
        self.buttonRect = QRect(button.x(), button.y(), button.width(), button.height())
        button.setStyleSheet("background-color: #ffffff; border: 1px solid #d3d3d3;")
        button.installEventFilter(self)

    def eventFilter(self, object, event):
        if object.property("objectName") == "spinBox":
            if event.type() == event.Enter:
                self.style = self.style() if self.style() else QStyle()
                overlay = self.style.generatedIconPixmap(QStyle.SP_ArrowUp, None)
                painter = QPainter(overlay)
                painter.setPen(QPen(QColor(233, 233, 233, 255), 3))
                painter.drawRect(self.buttonRect.x(), self.buttonRect.y(), self.buttonRect.width(), self.buttonRect.height())
                object.setIcon(QIcon(overlay))
            elif event.type() == event.Leave:
                object.setIcon(QIcon())

        return super().eventFilter(object, event)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    win = CustomSpinBox()
    win.show()
    sys.exit(app.exec_())

在不同的平台上，我们都可以应用上述代码，实现添加数值输入框鼠标悬停时边框的效果。