自定义Meter控件：实现数值显示与刻度的精致UI体验

外圆绘制：

float fltStartAngle = -90 - (meterDegrees) / 2 + 360;Rectangle r1 = new Rectangle(m_rectWorking.Location, new Size(m_rectWorking.Width, m_rectWorking.Width));g.DrawArc(new Pen(new SolidBrush(externalRoundColor), 1), r1, fltStartAngle, meterDegrees);

内圆绘制：

Rectangle r2 = new Rectangle(m_rectWorking.Left + (m_rectWorking.Width - m_rectWorking.Width / 4) / 2,                            m_rectWorking.Top + (m_rectWorking.Width - m_rectWorking.Width / 4) / 2,                            m_rectWorking.Width / 4, m_rectWorking.Width / 4);g.DrawArc(new Pen(new SolidBrush(insideRoundColor), 1), r2, fltStartAngle, meterDegrees);

刻度与数值绘制：

int _splitCount = splitCount * 2;float fltSplitValue = (float)meterDegrees / (float)_splitCount;for (int i = 0; i <= _splitCount; i++){    // 计算每个刻度的角度位置    float fltAngle = (fltStartAngle + fltSplitValue * i - 180) % 360;    // 绘制刻度线    float fltY1 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2) * Math.Sin(Math.PI * (fltAngle / 180.00F))));    float fltX1 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2) * Math.Cos(Math.PI * (fltAngle / 180.00F))));    // 文本绘制（偶数刻度）    if (i % 2 == 0)    {        // 详细计算并绘制数值显示        // ...    }    // 绘制刻度线    g.DrawLine(new Pen(new SolidBrush(scaleColor), i % 2 == 0 ? 2 : 1), new PointF(fltX1, fltY1), new PointF(fltX2, fltY2));}

指针绘制：

// 主指针g.FillEllipse(new SolidBrush(Color.FromArgb(100, pointerColor.R, pointerColor.G, pointerColor.B)),              new Rectangle(m_rectWorking.Left + m_rectWorking.Width / 2 - 10,                          m_rectWorking.Top + m_rectWorking.Width / 2 - 10, 20, 20));// 红色指针g.FillEllipse(Brushes.Red, new Rectangle(m_rectWorking.Left + m_rectWorking.Width / 2 - 5,                                       m_rectWorking.Top + m_rectWorking.Width / 2 - 5, 10, 10));