pyqt 实现环形进度

要实现环形进度条可以使用QProgressBar和QPainter来实现。

首先，创建一个QProgressBar并将其隐藏：

progress = QProgressBar(self)
progress.setGeometry(30, 40, 200, 200)
progress.setRange(0, 100)
progress.setTextVisible(False)
progress.hide()

然后，在绘制事件中使用QPainter绘制环形进度条：

def paintEvent(self, event):
    painter = QPainter(self)
    painter.setRenderHint(QPainter.Antialiasing)

    barWidth = 8
    barColor = QColor(255, 255, 255)

    # 绘制圆形
    painter.setPen(Qt.NoPen)
    painter.setBrush(QBrush(QColor("#333333")))
    painter.drawEllipse(self.rect().center(), 100, 100)

    # 绘制进度
    painter.setPen(Qt.NoPen)
    painter.setBrush(QBrush(barColor))

    value = progress.value()
    angle = value * 360.0 / progress.maximum()

    painter.drawPie(self.rect().center().x() - 100, self.rect().center().y() - 100, 200, 200, 90 * 16, -angle * 16)

    # 绘制圆环
    painter.setBrush(Qt.NoBrush)
    painter.setPen(QPen(barColor, barWidth))
    painter.drawEllipse(self.rect().center(), 100 - barWidth / 2, 100 - barWidth / 2)

在更新进度时，需要同时更新QProgressBar和重新绘制环形进度条：

def updateProgress(self, value):
    progress.setValue(value)
    self.update()

这样就可以实现一个简单的环形进度条了。完整代码如下：

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter, QBrush, QColor, QPen
from PyQt5.QtWidgets import QApplication, QWidget, QProgressBar
import sys

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setGeometry(300, 300, 280, 170)
        self.setWindowTitle('环形进度条')

        progress = QProgressBar(self)
        progress.setGeometry(30, 40, 200, 200)
        progress.setRange(0, 100)
        progress.setTextVisible(False)
        progress.hide()

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)

        barWidth = 8
        barColor = QColor(255, 255, 255)

        # 绘制圆形
        painter.setPen(Qt.NoPen)
        painter.setBrush(QBrush(QColor("#333333")))
        painter.drawEllipse(self.rect().center(), 100, 100)

        # 绘制进度
        painter.setPen(Qt.NoPen)
        painter.setBrush(QBrush(barColor))

        value = progress.value()
        angle = value * 360.0 / progress.maximum()

        painter.drawPie(self.rect().center().x() - 100, self.rect().center().y() - 100, 200, 200, 90 * 16, -angle * 16)

        # 绘制圆环
        painter.setBrush(Qt.NoBrush)
        painter.setPen(QPen(barColor, barWidth))
        painter.drawEllipse(self.rect().center(), 100 - barWidth / 2, 100 - barWidth / 2)

    def updateProgress(self, value):
        progress.setValue(value)
        self.update()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    ex.show()
    sys.exit(app.exec_())