1: public class Thermometer : IHttpHandler

   2: {

   3:     #region IHttpHandler Members 

   4:  

   5:     public bool IsReusable

   6:     {

   7:         get { return false; }

   8:     } 

   9:  

  10:     public void ProcessRequest(HttpContext context)

  11:     {

  12:         if (context.Request.QueryString["Percent"] != null)

  13:         {

  14:             int Percent = int.Parse(context.Request.QueryString["Percent"]);

  15:             int Max = int.Parse(context.Request.QueryString["Max"]);

  16:             bool Dollar = int.Parse(context.Request.QueryString["Dollars"]) == 1;

  17:             float Pixels=(float)Percent*2.15f;

  18:             Bitmap TempImage = new Bitmap(100, 270);

  19:             Graphics TempGraphics = Graphics.FromImage(TempImage);

  20:             TempGraphics.FillRectangle(Brushes.White, new Rectangle(0, 0, 100, 270));

  21:             Pen TempPen = new Pen(Color.Black);

  22:             Pen RedPen=new Pen(Color.Red);

  23:             TempGraphics.DrawArc(TempPen, 45, 230, 30, 30, 320, 260);

  24:             TempGraphics.DrawLine(TempPen, 49, 235, 49, 20);

  25:             TempGraphics.DrawLine(TempPen, 71, 235, 71, 20);

  26:             TempGraphics.DrawArc(TempPen, 49, 15, 22, 11, 180, 180);

  27:             GreyFloodFill(TempImage);

  28:             FloodFill(TempImage, Percent);

  29:             bool DrawText = true;

  30:             float Amount = Max;

  31:             for (float y = 20.0f; y < 235.0f; y += 10.75f)

  32:             {

  33:                 TempGraphics.DrawLine(TempPen, 49, y, 55, y);

  34:                 if (DrawText)

  35:                 {

  36:                     Font TempFont = new Font("Arial", 8.0f, FontStyle.Bold);

  37:                     if (Dollar)

  38:                     {

  39:                         TempGraphics.DrawString("$" + Amount.ToString(), TempFont, Brushes.Black, 5, y);

  40:                     }

  41:                     else

  42:                     {

  43:                         TempGraphics.DrawString(Amount.ToString(), TempFont, Brushes.Black, 5, y);

  44:                     }

  45:                     DrawText = false;

  46:                 }

  47:                 else DrawText = true;

  48:                 Amount -= ((Max / 100) * 5.0f);

  49:             } 

  50:  

  51:             string etag = "\"" + Percent.GetHashCode() + "\"";

  52:             string incomingEtag = context.Request.Headers["If-None-Match"]; 

  53:  

  54:             context.Response.Cache.SetExpires(DateTime.Now.ToUniversalTime().AddDays(1));

  55:             context.Response.Cache.SetCacheability(HttpCacheability.Public);

  56:             context.Response.Cache.SetMaxAge(new TimeSpan(7, 0, 0, 0));

  57:             context.Response.Cache.SetRevalidation(HttpCacheRevalidation.AllCaches);

  58:             context.Response.Cache.SetETag(etag); 

  59:  

  60:             if (String.Compare(incomingEtag, etag) == 0)

  61:             {

  62:                 context.Response.StatusCode = (int)HttpStatusCode.NotModified;

  63:                 context.Response.End();

  64:             }

  65:             else

  66:             {

  67:                 context.Response.ContentType = "image/Gif";

  68:                 TempImage.Save(context.Response.OutputStream, ImageFormat.Gif);

  69:             }

  70:         }

  71:     } 

  72:  

  73:     private void GreyFloodFill(Bitmap TempImage)

  74:     {

  75:         int RedColor = 255;

  76:         for (int y = 20; y <= 235; ++y)

  77:         {

  78:             for (int x = 50; x <= 70; ++x)

  79:             {

  80:                 float Distance = Math.Abs(60 - x);

  81:                 RedColor = (int)(255.0f * (1.0f - (Distance / 30.0f)));

  82:                 TempImage.SetPixel(x, y, Color.FromArgb(RedColor, RedColor, RedColor));

  83:             }

  84:         }

  85:     } 

  86:  

  87:     private void FloodFill(Bitmap TempImage,int Percent)

  88:     {

  89:         if (Percent == 100)

  90:         {

  91:             FillCircle(TempImage, 60, 245, 15);

  92:             FillCircle(TempImage, 60, 20, 10);

  93:             FillRectangle(TempImage, 60, 20, 235);

  94:         }

  95:         else

  96:         {

  97:             FillCircle(TempImage, 60, 245, 15);

  98:             FillRectangle(TempImage, 60, (int)(235.0f - ((float)Percent * 2.15f)), 235);

  99:         }

 100:     } 

 101:  

 102:     private void FillRectangle(Bitmap TempImage, int x, int y1,int y2)

 103:     {

 104:         int MaxDistance=10;

 105:         for (int i = x - MaxDistance; i < x + MaxDistance; ++i)

 106:         {

 107:             for (int j = y1; j < y2; ++j)

 108:             {

 109:                 float Distance = (float)Math.Abs((i - x));

 110:                 int RedColor = (int)(255.0f * (1.0f - (Distance / (2.0f * MaxDistance))));

 111:                 TempImage.SetPixel(i, j, Color.FromArgb(RedColor, 0, 0));

 112:             }

 113:         }

 114:     } 

 115:  

 116:     private void FillCircle(Bitmap TempImage, int x, int y, int MaxDistance)

 117:     {

 118:         for (int i = x - MaxDistance; i < x + MaxDistance; ++i)

 119:         {

 120:             for (int j = y - MaxDistance; j < y + MaxDistance; ++j)

 121:             {

 122:                 float Distance = (float)Math.Sqrt(((j - y) * (j - y)) + ((i - x) * (i - x)));

 123:                 if (Distance < MaxDistance)

 124:                 {

 125:                     int RedColor = (int)(255.0f * (1.0f - (Distance / (2.0f * MaxDistance))));

 126:                     TempImage.SetPixel(i, j, Color.FromArgb(RedColor, 0, 0));

 127:                 }

 128:             }

 129:         }

 130:     } 

 131:  

 132:     #endregion

 133: }