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c#中Winform自定义控件如何实现仪表盘功能

发表于：2024-11-22 作者：千家信息网编辑

千家信息网最后更新 2024年11月22日，这篇文章主要介绍c#中Winform自定义控件如何实现仪表盘功能，文中介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们一定要看完！准备工作依然使用GDI+画的，不懂的话就百度一下吧另外主要用到了三

千家信息网最后更新 2024年11月22日c#中Winform自定义控件如何实现仪表盘功能

这篇文章主要介绍c#中Winform自定义控件如何实现仪表盘功能，文中介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们一定要看完！

准备工作

依然使用GDI+画的，不懂的话就百度一下吧

另外主要用到了三角函数，如果不懂，可以向初中的数学老师再问问（你也可以百度一下）

开始

添加一个类UCMeter 继承 UserControl

首先添加一个需要控制的属性

private int splitCount = 10;     ///      /// Gets or sets the split count.     /// 
     /// The split count.     [Description("分隔刻度数量，>1"), Category("自定义")]     public int SplitCount     {       get { return splitCount; }      set      {        if (value < 1)          return;        splitCount = value;        Refresh();      }    }    private int meterDegrees = 150;    ///     /// Gets or sets the meter degrees.    /// 
    /// The meter degrees.    [Description("表盘跨度角度，0-360"), Category("自定义")]    public int MeterDegrees    {      get { return meterDegrees; }      set      {        if (value > 360 || value <= 0)          return;        meterDegrees = value;        Refresh();      }    }    private decimal minValue = 0;    ///     /// Gets or sets the minimum value.    /// 
    /// The minimum value.    [Description("最小值,= maxValue)          return;        minValue = value;        Refresh();      }    }    private decimal maxValue = 100;    ///     /// Gets or sets the maximum value.    /// 
    /// The maximum value.    [Description("最大值,>MinValue"), Category("自定义")]    public decimal MaxValue    {      get { return maxValue; }      set      {        if (value <= minValue)          return;        maxValue = value;        Refresh();      }    }    ///     /// 获取或设置控件显示的文字的字体。    /// 
    /// The font.    ///     ///      ///      ///      ///      ///     [Description("刻度字体"), Category("自定义")]    public override Font Font    {      get      {        return base.Font;      }      set      {        base.Font = value;        Refresh();      }    }    private decimal m_value = 0;    ///     /// Gets or sets the value.    /// 
    /// The value.    [Description("值，>=MinValue并且<=MaxValue"), Category("自定义")]    public decimal Value    {      get { return m_value; }      set      {        if (value < minValue || value > maxValue)          return;        m_value = value;        Refresh();      }    }    private MeterTextLocation textLocation = MeterTextLocation.None;    ///     /// Gets or sets the text location.    /// 
    /// The text location.    [Description("值和固定文字显示位置"), Category("自定义")]    public MeterTextLocation TextLocation    {      get { return textLocation; }      set      {        textLocation = value;        Refresh();      }    }    private string fixedText;    ///     /// Gets or sets the fixed text.    /// 
    /// The fixed text.    [Description("固定文字"), Category("自定义")]    public string FixedText    {      get { return fixedText; }      set      {        fixedText = value;        Refresh();      }    }    private Font textFont = DefaultFont;    ///     /// Gets or sets the text font.    /// 
    /// The text font.    [Description("值和固定文字字体"), Category("自定义")]    public Font TextFont    {      get { return textFont; }      set      {        textFont = value;        Refresh();      }    }    private Color externalRoundColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the external round.    /// 
    /// The color of the external round.    [Description("外圆颜色"), Category("自定义")]    public Color ExternalRoundColor    {      get { return externalRoundColor; }      set      {        externalRoundColor = value;        Refresh();      }    }    private Color insideRoundColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the inside round.    /// 
    /// The color of the inside round.    [Description("内圆颜色"), Category("自定义")]    public Color InsideRoundColor    {      get { return insideRoundColor; }      set      {        insideRoundColor = value;        Refresh();      }    }    private Color boundaryLineColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the boundary line.    /// 
    /// The color of the boundary line.    [Description("边界线颜色"), Category("自定义")]    public Color BoundaryLineColor    {      get { return boundaryLineColor; }      set      {        boundaryLineColor = value;        Refresh();      }    }    private Color scaleColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the scale.    /// 
    /// The color of the scale.    [Description("刻度颜色"), Category("自定义")]    public Color ScaleColor    {      get { return scaleColor; }      set      {        scaleColor = value;        Refresh();      }    }    private Color scaleValueColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the scale value.    /// 
    /// The color of the scale value.    [Description("刻度值文字颜色"), Category("自定义")]    public Color ScaleValueColor    {      get { return scaleValueColor; }      set      {        scaleValueColor = value;        Refresh();      }    }    private Color pointerColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the pointer.    /// 
    /// The color of the pointer.    [Description("指针颜色"), Category("自定义")]    public Color PointerColor    {      get { return pointerColor; }      set      {        pointerColor = value;        Refresh();      }    }    private Color textColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the text.    /// 
    /// The color of the text.    [Description("值和固定文字颜色"), Category("自定义")]    public Color TextColor    {      get { return textColor; }      set      {        textColor = value;        Refresh();      }    }    Rectangle m_rectWorking;

重绘

protected override void OnPaint(PaintEventArgs e)     {       base.OnPaint(e);       var g = e.Graphics;       g.SetGDIHigh();       //外圆       float fltStartAngle = -90 - (meterDegrees) / 2 + 360;       var 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       var 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);       //边界线       if (meterDegrees != 360)       {         float fltAngle = fltStartAngle - 180;         float intY = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - m_rectWorking.Width / 8) * Math.Sin(Math.PI * (fltAngle / 180.00F))));         float intX = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - m_rectWorking.Width / 8) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));         float fltY1 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - (m_rectWorking.Width / 8 * Math.Sin(Math.PI * (fltAngle / 180.00F))));         float fltX1 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - (m_rectWorking.Width / 8 * Math.Cos(Math.PI * (fltAngle / 180.00F)))));         g.DrawLine(new Pen(new SolidBrush(boundaryLineColor), 1), new PointF(intX, intY), new PointF(fltX1, fltY1));         g.DrawLine(new Pen(new SolidBrush(boundaryLineColor), 1), new PointF(m_rectWorking.Right - (fltX1 - m_rectWorking.Left), fltY1), new PointF(m_rectWorking.Right - (intX - m_rectWorking.Left), intY));       }       //分割线       int _splitCount = splitCount * 2;       float fltSplitValue = (float)meterDegrees / (float)_splitCount;       for (int i = 0; i <= _splitCount; i++)       {         float fltAngle = (fltStartAngle + fltSplitValue * i - 180) % 360;         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)))));         float fltY2 = 0;         float fltX2 = 0;         if (i % 2 == 0)         {           fltY2 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 10) * Math.Sin(Math.PI * (fltAngle / 180.00F))));           fltX2 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 10) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));           if (!(meterDegrees == 360 && i == _splitCount))           {             decimal decValue = minValue + (maxValue - minValue) / _splitCount * i;             var txtSize = g.MeasureString(decValue.ToString("0.##"), this.Font);             float fltFY1 = (float)(m_rectWorking.Top - txtSize.Height / 2 + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 20) * Math.Sin(Math.PI * (fltAngle / 180.00F))));             float fltFX1 = (float)(m_rectWorking.Left - txtSize.Width / 2 + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 20) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));             g.DrawString(decValue.ToString("0.##"), Font, new SolidBrush(scaleValueColor), fltFX1, fltFY1);           }         }         else         {           fltY2 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 5) * Math.Sin(Math.PI * (fltAngle / 180.00F))));           fltX2 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 5) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));         }         g.DrawLine(new Pen(new SolidBrush(scaleColor), i % 2 == 0 ? 2 : 1), new PointF(fltX1, fltY1), new PointF(fltX2, fltY2));       }       //值文字和固定文字       if (textLocation != MeterTextLocation.None)       {         string str = m_value.ToString("0.##");         var txtSize = g.MeasureString(str, textFont);         float fltY = m_rectWorking.Top + m_rectWorking.Width / 4 - txtSize.Height / 2;         float fltX = m_rectWorking.Left + m_rectWorking.Width / 2 - txtSize.Width / 2;         g.DrawString(str, textFont, new SolidBrush(textColor), new PointF(fltX, fltY));         if (!string.IsNullOrEmpty(fixedText))         {           str = fixedText;           txtSize = g.MeasureString(str, textFont);           fltY = m_rectWorking.Top + m_rectWorking.Width / 4 + txtSize.Height / 2;           fltX = m_rectWorking.Left + m_rectWorking.Width / 2 - txtSize.Width / 2;           g.DrawString(str, textFont, new SolidBrush(textColor), new PointF(fltX, fltY));         }       }       //画指针       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));       g.FillEllipse(Brushes.Red, new Rectangle(m_rectWorking.Left + m_rectWorking.Width / 2 - 5, m_rectWorking.Top + m_rectWorking.Width / 2 - 5, 10, 10));       float fltValueAngle = (fltStartAngle + ((float)(m_value - minValue) / (float)(maxValue - minValue)) * (float)meterDegrees - 180) % 360;       float intValueY1 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 30) * Math.Sin(Math.PI * (fltValueAngle / 180.00F))));       float intValueX1 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 30) * Math.Cos(Math.PI * (fltValueAngle / 180.00F)))));       g.DrawLine(new Pen(new SolidBrush(pointerColor), 3), intValueX1, intValueY1, m_rectWorking.Left + m_rectWorking.Width / 2, m_rectWorking.Top + m_rectWorking.Width / 2);     }

还有一个显示文字位置的枚举

///    /// Enum MeterTextLocation   /// 
   public enum MeterTextLocation   {     ///      /// The none     /// 
     None,     ///      /// The top     /// 
     Top,     ///      /// The bottom     /// 
     Bottom   }

代码就这么多了，看完整代码

// ***********************************************************************// Assembly     : HZH_Controls// Created     : 2019-09-03//// ***********************************************************************// //   Copyright by Huang Zhenghui(黄正辉) All, QQ group:568015492 QQ:623128629 Email:623128629@qq.com// //// Blog: https://www.cnblogs.com/bfyx// GitHub：https://github.com/kwwwvagaa/NetWinformControl// gitee：https://gitee.com/kwwwvagaa/net_winform_custom_control.git//// If you use this code, please keep this note.// ***********************************************************************using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows.Forms;using System.Drawing;using System.Drawing.Drawing2D;using System.ComponentModel;namespace HZH_Controls.Controls{  ///   /// Class UCMeter.  /// Implements the   /// 
  ///   public class UCMeter : UserControl  {    private int splitCount = 10;    ///     /// Gets or sets the split count.    /// 
    /// The split count.    [Description("分隔刻度数量，>1"), Category("自定义")]    public int SplitCount    {      get { return splitCount; }      set      {        if (value < 1)          return;        splitCount = value;        Refresh();      }    }    private int meterDegrees = 150;    ///     /// Gets or sets the meter degrees.    /// 
    /// The meter degrees.    [Description("表盘跨度角度，0-360"), Category("自定义")]    public int MeterDegrees    {      get { return meterDegrees; }      set      {        if (value > 360 || value <= 0)          return;        meterDegrees = value;        Refresh();      }    }    private decimal minValue = 0;    ///     /// Gets or sets the minimum value.    /// 
    /// The minimum value.    [Description("最小值,= maxValue)          return;        minValue = value;        Refresh();      }    }    private decimal maxValue = 100;    ///     /// Gets or sets the maximum value.    /// 
    /// The maximum value.    [Description("最大值,>MinValue"), Category("自定义")]    public decimal MaxValue    {      get { return maxValue; }      set      {        if (value <= minValue)          return;        maxValue = value;        Refresh();      }    }    ///     /// 获取或设置控件显示的文字的字体。    /// 
    /// The font.    ///     ///      ///      ///      ///      ///     [Description("刻度字体"), Category("自定义")]    public override Font Font    {      get      {        return base.Font;      }      set      {        base.Font = value;        Refresh();      }    }    private decimal m_value = 0;    ///     /// Gets or sets the value.    /// 
    /// The value.    [Description("值，>=MinValue并且<=MaxValue"), Category("自定义")]    public decimal Value    {      get { return m_value; }      set      {        if (value < minValue || value > maxValue)          return;        m_value = value;        Refresh();      }    }    private MeterTextLocation textLocation = MeterTextLocation.None;    ///     /// Gets or sets the text location.    /// 
    /// The text location.    [Description("值和固定文字显示位置"), Category("自定义")]    public MeterTextLocation TextLocation    {      get { return textLocation; }      set      {        textLocation = value;        Refresh();      }    }    private string fixedText;    ///     /// Gets or sets the fixed text.    /// 
    /// The fixed text.    [Description("固定文字"), Category("自定义")]    public string FixedText    {      get { return fixedText; }      set      {        fixedText = value;        Refresh();      }    }    private Font textFont = DefaultFont;    ///     /// Gets or sets the text font.    /// 
    /// The text font.    [Description("值和固定文字字体"), Category("自定义")]    public Font TextFont    {      get { return textFont; }      set      {        textFont = value;        Refresh();      }    }    private Color externalRoundColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the external round.    /// 
    /// The color of the external round.    [Description("外圆颜色"), Category("自定义")]    public Color ExternalRoundColor    {      get { return externalRoundColor; }      set      {        externalRoundColor = value;        Refresh();      }    }    private Color insideRoundColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the inside round.    /// 
    /// The color of the inside round.    [Description("内圆颜色"), Category("自定义")]    public Color InsideRoundColor    {      get { return insideRoundColor; }      set      {        insideRoundColor = value;        Refresh();      }    }    private Color boundaryLineColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the boundary line.    /// 
    /// The color of the boundary line.    [Description("边界线颜色"), Category("自定义")]    public Color BoundaryLineColor    {      get { return boundaryLineColor; }      set      {        boundaryLineColor = value;        Refresh();      }    }    private Color scaleColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the scale.    /// 
    /// The color of the scale.    [Description("刻度颜色"), Category("自定义")]    public Color ScaleColor    {      get { return scaleColor; }      set      {        scaleColor = value;        Refresh();      }    }    private Color scaleValueColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the scale value.    /// 
    /// The color of the scale value.    [Description("刻度值文字颜色"), Category("自定义")]    public Color ScaleValueColor    {      get { return scaleValueColor; }      set      {        scaleValueColor = value;        Refresh();      }    }    private Color pointerColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the pointer.    /// 
    /// The color of the pointer.    [Description("指针颜色"), Category("自定义")]    public Color PointerColor    {      get { return pointerColor; }      set      {        pointerColor = value;        Refresh();      }    }    private Color textColor = Color.FromArgb(255, 77, 59);    ///     /// Gets or sets the color of the text.    /// 
    /// The color of the text.    [Description("值和固定文字颜色"), Category("自定义")]    public Color TextColor    {      get { return textColor; }      set      {        textColor = value;        Refresh();      }    }    Rectangle m_rectWorking;    public UCMeter()    {      this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);      this.SetStyle(ControlStyles.DoubleBuffer, true);      this.SetStyle(ControlStyles.ResizeRedraw, true);      this.SetStyle(ControlStyles.Selectable, true);      this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);      this.SetStyle(ControlStyles.UserPaint, true);      this.SizeChanged += UCMeter1_SizeChanged;      this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;      this.Size = new Size(350, 200);    }    void UCMeter1_SizeChanged(object sender, EventArgs e)    {      m_rectWorking = new Rectangle(10, 10, this.Width - 20, this.Height - 20);    }    protected override void OnPaint(PaintEventArgs e)    {      base.OnPaint(e);      var g = e.Graphics;      g.SetGDIHigh();      //外圆      float fltStartAngle = -90 - (meterDegrees) / 2 + 360;      var 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      var 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);      //边界线      if (meterDegrees != 360)      {        float fltAngle = fltStartAngle - 180;        float intY = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - m_rectWorking.Width / 8) * Math.Sin(Math.PI * (fltAngle / 180.00F))));        float intX = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - m_rectWorking.Width / 8) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));        float fltY1 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - (m_rectWorking.Width / 8 * Math.Sin(Math.PI * (fltAngle / 180.00F))));        float fltX1 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - (m_rectWorking.Width / 8 * Math.Cos(Math.PI * (fltAngle / 180.00F)))));        g.DrawLine(new Pen(new SolidBrush(boundaryLineColor), 1), new PointF(intX, intY), new PointF(fltX1, fltY1));        g.DrawLine(new Pen(new SolidBrush(boundaryLineColor), 1), new PointF(m_rectWorking.Right - (fltX1 - m_rectWorking.Left), fltY1), new PointF(m_rectWorking.Right - (intX - m_rectWorking.Left), intY));      }      //分割线      int _splitCount = splitCount * 2;      float fltSplitValue = (float)meterDegrees / (float)_splitCount;      for (int i = 0; i <= _splitCount; i++)      {        float fltAngle = (fltStartAngle + fltSplitValue * i - 180) % 360;        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)))));        float fltY2 = 0;        float fltX2 = 0;        if (i % 2 == 0)        {          fltY2 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 10) * Math.Sin(Math.PI * (fltAngle / 180.00F))));          fltX2 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 10) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));          if (!(meterDegrees == 360 && i == _splitCount))          {            decimal decValue = minValue + (maxValue - minValue) / _splitCount * i;            var txtSize = g.MeasureString(decValue.ToString("0.##"), this.Font);            float fltFY1 = (float)(m_rectWorking.Top - txtSize.Height / 2 + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 20) * Math.Sin(Math.PI * (fltAngle / 180.00F))));            float fltFX1 = (float)(m_rectWorking.Left - txtSize.Width / 2 + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 20) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));            g.DrawString(decValue.ToString("0.##"), Font, new SolidBrush(scaleValueColor), fltFX1, fltFY1);          }        }        else        {          fltY2 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 5) * Math.Sin(Math.PI * (fltAngle / 180.00F))));          fltX2 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 5) * Math.Cos(Math.PI * (fltAngle / 180.00F)))));        }        g.DrawLine(new Pen(new SolidBrush(scaleColor), i % 2 == 0 ? 2 : 1), new PointF(fltX1, fltY1), new PointF(fltX2, fltY2));      }      //值文字和固定文字      if (textLocation != MeterTextLocation.None)      {        string str = m_value.ToString("0.##");        var txtSize = g.MeasureString(str, textFont);        float fltY = m_rectWorking.Top + m_rectWorking.Width / 4 - txtSize.Height / 2;        float fltX = m_rectWorking.Left + m_rectWorking.Width / 2 - txtSize.Width / 2;        g.DrawString(str, textFont, new SolidBrush(textColor), new PointF(fltX, fltY));        if (!string.IsNullOrEmpty(fixedText))        {          str = fixedText;          txtSize = g.MeasureString(str, textFont);          fltY = m_rectWorking.Top + m_rectWorking.Width / 4 + txtSize.Height / 2;          fltX = m_rectWorking.Left + m_rectWorking.Width / 2 - txtSize.Width / 2;          g.DrawString(str, textFont, new SolidBrush(textColor), new PointF(fltX, fltY));        }      }      //画指针      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));      g.FillEllipse(Brushes.Red, new Rectangle(m_rectWorking.Left + m_rectWorking.Width / 2 - 5, m_rectWorking.Top + m_rectWorking.Width / 2 - 5, 10, 10));      float fltValueAngle = (fltStartAngle + ((float)(m_value - minValue) / (float)(maxValue - minValue)) * (float)meterDegrees - 180) % 360;      float intValueY1 = (float)(m_rectWorking.Top + m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 30) * Math.Sin(Math.PI * (fltValueAngle / 180.00F))));      float intValueX1 = (float)(m_rectWorking.Left + (m_rectWorking.Width / 2 - ((m_rectWorking.Width / 2 - 30) * Math.Cos(Math.PI * (fltValueAngle / 180.00F)))));      g.DrawLine(new Pen(new SolidBrush(pointerColor), 3), intValueX1, intValueY1, m_rectWorking.Left + m_rectWorking.Width / 2, m_rectWorking.Top + m_rectWorking.Width / 2);    }  }  ///   /// Enum MeterTextLocation  /// 
  public enum MeterTextLocation  {    ///     /// The none    /// 
    None,    ///     /// The top    /// 
    Top,    ///     /// The bottom    /// 
    Bottom  }}