graphicsView仪表盘

graphicsView是Qt中的一个图形视图框架，可以用于创建各种自定义图形界面元素，包括仪表盘。下面是一个简单的graphicsView仪表盘的实现示例：

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *

class GaugeWidget(QWidget):
    def __init__(self, parent=None):
        super(GaugeWidget, self).__init__(parent)
        self.value = 0
        self.minValue = 0
        self.maxValue = 100
        self.warningValue = 80
        self.alarmValue = 90
        self.backgroundColor = Qt.white
        self.needleColor = Qt.red
        self.warningColor = Qt.yellow
        self.alarmColor = Qt.red
        self.textColor = Qt.black
        self.font = QFont('Arial', 12)
        self.setFixedSize(200, 200)

    def setValue(self, value):
        self.value = value
        self.update()

    def setRange(self, minValue, maxValue):
        self.minValue = minValue
        self.maxValue = maxValue
        self.update()

    def setWarningRange(self, warningValue, alarmValue):
        self.warningValue = warningValue
        self.alarmValue = alarmValue
        self.update()

    def setBackgroundColor(self, color):
        self.backgroundColor = color
        self.update()

    def setNeedleColor(self, color):
        self.needleColor = color
        self.update()

    def setWarningColor(self, color):
        self.warningColor = color
        self.update()

    def setAlarmColor(self, color):
        self.alarmColor = color
        self.update()

    def setTextColor(self, color):
        self.textColor = color
        self.update()

    def setFont(self, font):
        self.font = font
        self.update()

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

        rect = QRectF(10, 10, self.width() - 20, self.height() - 20)
        startAngle = 45
        spanAngle = 270
        valueAngle = startAngle + (self.value - self.minValue) * spanAngle / (self.maxValue - self.minValue)

        # 绘制刻度盘
        painter.save()
        painter.translate(self.width() / 2, self.height() / 2)
        painter.rotate(startAngle)
        painter.setPen(QPen(Qt.black, 2))
        painter.setFont(self.font)
        for i in range(11):
            angle = i * spanAngle / 10
            painter.drawLine(rect.width() / 2, 0, rect.width() / 2 - 20, 0)
            painter.drawText(rect.width() / 2 - 30, -5, 20, 10, Qt.AlignCenter, str(int(self.minValue + i * (self.maxValue - self.minValue) / 10)))
            painter.rotate(angle)
        painter.restore()

        # 绘制指针
        painter.save()
        painter.translate(self.width() / 2, self.height() / 2)
        painter.rotate(valueAngle)
        painter.setPen(QPen(self.needleColor, 3))
        painter.drawLine(0, 0, rect.width() / 2 - 20, 0)
        painter.restore()

        # 绘制警告区域
        painter.save()
        painter.translate(self.width() / 2, self.height() / 2)
        painter.rotate(startAngle)
        painter.setPen(QPen(self.warningColor, 10))
        painter.drawArc(rect, spanAngle * self.warningValue / (self.maxValue - self.minValue), spanAngle * (self.alarmValue - self.warningValue) / (self.maxValue - self.minValue))
        painter.restore()

        # 绘制报警区域
        painter.save()
        painter.translate(self.width() / 2, self.height() / 2)
        painter.rotate(startAngle)
        painter.setPen(QPen(self.alarmColor, 10))
        painter.drawArc(rect, spanAngle * self.alarmValue / (self.maxValue - self.minValue), spanAngle * (self.maxValue - self.alarmValue) / (self.maxValue - self.minValue))
        painter.restore()

        # 绘制数值
        painter.setPen(QPen(self.textColor))
        painter.setFont(self.font)
        painter.drawText(0, self.height() - 20, self.width(), 20, Qt.AlignCenter, str(self.value))

使用该类创建一个仪表盘的示例代码如下：

app = QApplication(sys.argv)
gauge = GaugeWidget()
gauge.setRange(0, 200)
gauge.setWarningRange(160, 180)
gauge.setValue(100)
gauge.show()
sys.exit(app.exec_())

该示例创建了一个范围为0到200的仪表盘，警告区域为160到180，当前值为100。可以根据需要调整范围、警告区域和当前值等参数。