PyQt5 QSpinBox – 为向下箭头添加边框

PyQt5是一个流行的Python GUI开发工具包，其中的QSpinBox控件可以用来增加或减少数字。在QSpinBox控件中，可以通过添加边框来美化向下箭头，下面是完整的使用攻略：

1. 引入必要的库和模块

要使用PyQt5 QSpinBox控件，我们需要引入以下的库和模块:

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QSpinBox
from PyQt5.QtGui import QPainter, QColor, QPen
from PyQt5.QtCore import Qt

2. 创建SpinBox对象

创建SpinBox对象的代码如下:

spinbox = QSpinBox()

3. 添加边框

通过绘制向下箭头的边框，我们可以添加边框。做法是继承QSpinBox并重写paintEvent()函数。代码如下：

class MySpinBox(QSpinBox):
    def __init__(self):
        super(MySpinBox, self).__init__()
    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.fillRect(self.rect(), QColor(255, 255, 255))
        painter.setPen(QPen(QColor(240, 240, 240), 2))
        painter.drawLine(0, self.height() - 2, self.width(), self.height() - 2)
        painter.drawLine(self.width() - 2, 0, self.width() - 2, self.height())
        painter.setPen(QColor(0, 0, 0))
        painter.drawLine(0, self.height() - 1, self.width(), self.height() - 1)
        painter.drawLine(self.width() - 1, 0, self.width() - 1, self.height())

spinbox = MySpinBox()

示例说明

示例1: 对于一个QSpinBox控件，我们可以使用以下代码来创建一个带边框的SpinBox控件：

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QSpinBox
from PyQt5.QtGui import QPainter, QColor, QPen
from PyQt5.QtCore import Qt

class MySpinBox(QSpinBox):
    def __init__(self):
        super(MySpinBox, self).__init__()
    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.fillRect(self.rect(), QColor(255, 255, 255))
        painter.setPen(QPen(QColor(240, 240, 240), 2))
        painter.drawLine(0, self.height() - 2, self.width(), self.height() - 2)
        painter.drawLine(self.width() - 2, 0, self.width() - 2, self.height())
        painter.setPen(QColor(0, 0, 0))
        painter.drawLine(0, self.height() - 1, self.width(), self.height() - 1)
        painter.drawLine(self.width() - 1, 0, self.width() - 1, self.height())

if __name__ == '__main__':
    app = QApplication([])
    my_widget = QWidget()
    layout = QVBoxLayout()
    spinbox = MySpinBox()
    layout.addWidget(spinbox)
    my_widget.setLayout(layout)
    my_widget.show()
    app.exec_()

示例2: 在一个QMainWindow窗口中，我们可以使用以下代码来创建多个带边框的SpinBox控件。

from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QSpinBox, QWidget
from PyQt5.QtGui import QPainter, QColor, QPen
from PyQt5.QtCore import Qt

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.init_ui()

    def init_ui(self):
        # 设置窗口大小和标题
        self.setGeometry(100, 100, 200, 200)
        self.setWindowTitle('QSpinBox with border')

        # 创建一个widget，用于放置QSpinBox
        widget = QWidget()
        layout = QVBoxLayout(widget)

        # 创建多个带边框的QSpinBox
        for i in range(5):
            spinbox = QSpinBox()
            spinbox.setStyleSheet('QSpinBox {font-weight: bold; font-size: 20px}')
            spinbox_layout = QVBoxLayout()
            spinbox_layout.addWidget(spinbox)
            spinbox.setLayout(spinbox_layout)

            layout.addWidget(spinbox)

        self.setCentralWidget(widget)

if __name__ == '__main__':
    app = QApplication([])
    window = MainWindow()
    window.show()
    app.exec_()