compare-chart.aspx

ASP.NET Web Forms Techniques

  oPen.EndCap = System.Drawing.Drawing2D.LineCap.ArrowAnchor;
  oGraphics.DrawLine(oPen, 120, 261, 399, 261);   // X Axis
  oPen.EndCap = System.Drawing.Drawing2D.LineCap.NoAnchor;
  oGraphics.DrawLine(oPen, 120, 17, 120, 261);    // Y Axis

  // draw the "key" boxes for each of the 6 possible
  // values (gears) using column names from DataTable
  for (int iLoop = 0; iLoop <= 5; iLoop++) {

    // get column name to display
    sText = oXData.Columns[iLoop + 1].ColumnName;

    // calculate position
    iKeyXTop = 295 + ((iLoop / 3) * 17);
    int iMod3 = iLoop;
    while (iMod3 >= 3) iMod3 -= 3;
    iKeyXLeft = (int)(120 + (iMod3 * 110));

    // set brush color and draw shadow for box
    oBrush.Color = Color.FromArgb(102, 102, 102);
    oGraphics.FillRectangle(oBrush, iKeyXLeft + 1, iKeyXTop + 1, 15, 13);

    // set brush color and draw box and text
    oBrush.Color = aColors[iLoop + 1];
    oGraphics.FillRectangle(oBrush, iKeyXLeft, iKeyXTop, 15, 13);
    DrawText(iKeyXLeft + 18, iKeyXTop, 115, 14, sText,
             null, 0, "", StringAlignment.Near, 0);

  }

  // next, find maximum value from all rows
  int iValue, iRowsMax, iMaxValue;
  iRowsMax = 0;
  foreach (DataRow oRow in oXData.Rows) {
    for (int iLoop = 1; iLoop < oXData.Columns.Count; iLoop++) {
      try {
        iValue = (short)oRow[iLoop];
        if (iValue > iRowsMax) {
          iRowsMax = iValue;
        }
      }
      catch (Exception e) {
      }
    }
  }

  // round up to next iYInterval
  iMaxValue = ((iRowsMax + iYInterval) / iYInterval) * iYInterval;

  // calculate number of values and pixel spacing
  int iXValCount = (iMaxValue / iYInterval) + 1;
  int iXSpacePX = 270 / (iXValCount - 1);

  // see if the captions will overlap
  while (iXSpacePX < 25) {

    // double the interval size
    iYInterval = iYInterval * 2;

    // recalculate values based on this interval size
    iMaxValue = ((iRowsMax + iYInterval) / iYInterval) * iYInterval;
    iXValCount = (iMaxValue / iYInterval) + 1;
    iXSpacePX = 270 / (iXValCount - 1);
  }

  // for each value on X axis
  for (int iLoop = 0; iLoop < iXValCount; iLoop++) {

    // get value to display along axis
    iValue = iYInterval * iLoop;

    // calculate horizontal position and write text
    iTextPos = iLoop * iXSpacePX;
    DrawText(96 + iTextPos, 263, 50, 12, iValue.ToString(),
             null, 0, "", StringAlignment.Center, 0);

    // draw light gray vertical line if not on Y axis
    if (iLoop > 0) {
      oPen.Color = Color.FromArgb(204, 204, 204);  // light gray
      oGraphics.DrawLine(oPen, 120 + iTextPos, 17, 120 + iTextPos, 260);
    }
  }

  // write X axis caption aligned right
  DrawText(40, 274, 355, 15, sXAxisText, null, 0, "", StringAlignment.Far, 0);

  // calculate multiplier for X values per pixel
  Single fXMultiplier = 270 / iMaxValue;

  // create index for row to set vertical position
  int iRowCount = 0;

  // calculate vertical space for each row on Y axis
  int iYSpacePX = 240 / oXData.Rows.Count;

  // make each bar 3/4 of available space to provide
  // gap between each one so scale rules are visible
  int iYBarHeight = (int)(iYSpacePX * 0.75);
  int iYBarAbove = (int)(iYSpacePX * 0.125);

  // iterate through data rows
  foreach (DataRow oRow in oXData.Rows) {

    // calculate vertical position for row values
    iRectYStart = 18 + (iRowCount * iYSpacePX);

    // draw the vehicle name (caption) left of Y axis
    DrawText(0, iRectYStart, 118, iYBarHeight + iYBarAbove, oRow[0].ToString(),
             null, 0, "", StringAlignment.Far, 0);

    // flag so that shadow is only drawn once
    Boolean bDrawShadow = true;

    // iterate through the columns of this row
    for (int iLoop = (oXData.Columns.Count - 1); iLoop > 1; iLoop--) {
      try {
        iValue = (short)oRow[iLoop];
        iRectWidth = (int)(iValue * fXMultiplier);

        if (bDrawShadow) {

          // if this is the first value box for this row
          // then set brush color and draw shadow for bar
          oBrush.Color = Color.FromArgb(102, 102, 102);
          oGraphics.FillRectangle(oBrush, 121, iRectYStart + iYBarAbove, iRectWidth + 1, iYBarHeight + 1);
          bDrawShadow = false;   // clear flag
        }

        // set brush color and draw value bar
        oBrush.Color = aColors[iLoop];
        oGraphics.FillRectangle(oBrush, 121, iRectYStart + iYBarAbove, iRectWidth, iYBarHeight);
      }
      catch (Exception e) {
      }
    }

    iRowCount += 1;
  }
}

// -------------------------------------------------------------------

void FillColorArray() {

  // fill the array of colors for chart items
  // use browser-safe colors (multiples of #33)
  aColors[1] = Color.FromArgb(255, 0, 0);      // light red
  aColors[2] = Color.FromArgb(0, 102, 204);    // light blue
  aColors[3] = Color.FromArgb(0, 204, 0);      // light green
  aColors[4] = Color.FromArgb(204, 204, 0);    // gold
  aColors[5] = Color.FromArgb(255, 153, 0);    // orange
  aColors[6] = Color.FromArgb(102, 0, 102);    // purple
  aColors[7] = Color.FromArgb(255, 0, 255);    // magenta
  aColors[8] = Color.FromArgb(153, 0, 0);      // dark red
  aColors[9] = Color.FromArgb(102, 153, 153);  // teal
  aColors[10] = Color.FromArgb(0, 0, 102);     // dark blue
  aColors[11] = Color.FromArgb(0, 0, 255);     // cyan
  aColors[12] = Color.FromArgb(102, 102, 102); // dark gray
}

// -------------------------------------------------------------------

// routine to draw error message on bitmap
void DrawErrorMessage(String sError) {
   DrawText(35, 0, 365, 50, sError, FontStyle.Bold, 10, "Red", null, 0);
}

// -------------------------------------------------------------------

// routine to draw text string in rectangle on bitmap
void DrawText(int iTop, int iLeft, int iWidth,
             int iHeight, String sText, object eFontStyle,
             int iFontSize, String sColor, object eAlign,
             StringFormatFlags eFlag) {

  // set default values if not specified
  if (eFontStyle == null) eFontStyle = FontStyle.Regular;
  if (iFontSize == 0) iFontSize = 8;
  if (sColor == "") sColor = "Black";
  if (eAlign == null) eAlign = StringAlignment.Near;

  // create the rectange to hold the text
  RectangleF oRect = new RectangleF(iTop, iLeft, iWidth, iHeight);

  // create a Font object for the text style
  Font oFont = new Font("Arial", iFontSize, (FontStyle)eFontStyle);

  // create the format object to define the format and style
  StringFormat oFormat = new StringFormat(eFlag);
  oFormat.Alignment = (StringAlignment)eAlign;      // horizontal alignment
  // always center vertically within rectangle area
  oFormat.LineAlignment = StringAlignment.Center;

  // create a brush object and draw the text
  SolidBrush oBrush = new SolidBrush(Color.FromName(sColor));
  oGraphics.DrawString(sText, oFont, oBrush, oRect, oFormat);
}

// -------------------------------------------------------------------

// function to create the DataSet of values
// does the same as in the compare.aspx page
DataSet GetCompareDS() {
  String sConnect = ConfigurationSettings.AppSettings["XroxCarsConnectString"];
  String sSQL = GetSqlStatement();
  DataSet dsResult = new DataSet();
  try {
    SqlConnection oConn = new SqlConnection(sConnect);
    SqlDataAdapter oDA = new SqlDataAdapter(sSQL, oConn);
    oDA.Fill(dsResult, "Compare");
  }
  catch (Exception e) {
    DrawErrorMessage("Database cannot be accessed");
  }
  return dsResult;
}

// -------------------------------------------------------------------

// function to create appropriate SQL statement
String GetSqlStatement() {

  String sResult = "";

  // see which comparison type is selected
  // and create SELECT part of SQL statement
  switch(sCompareIndex) {

    case "0":    // compare Performance
      sCaption = "Time in seconds from standing start to reach speed (mph) of:";
      sResult = "SELECT Caption = Model + ' ' + EngineName, "
              + "[30] = Perf30, [40] = Perf40, [50] = Perf50, "
              + "[60] = Perf60, [70] = Perf70, [80] = Perf80, "
              + "[90] = Perf90, [100] = Perf100 "
              + "FROM (tblCar JOIN tblCarEngines "
              + "ON tblCar.CarID = tblCarEngines.CarID) "
              + "JOIN tblEngine "
              + "ON tblEngine.EngineID = tblCarEngines.EngineID WHERE ";
      break;

    case "1":    // compare Maximum Speed
      sCaption = "Maximum speed (mph) in each gear:";
      sResult = "SELECT Caption = Model + ' ' + EngineName, "
              + "[1st gear] = Speed1st, [2nd gear] = Speed2nd, "
              + "[3rd gear] = Speed3rd, [4th gear] = Speed4th, "
              + "[5th gear] = Speed5th, [6th gear] = Speed6th "
              + "FROM (tblCar JOIN tblCarEngines "
              + "ON tblCar.CarID = tblCarEngines.CarID) "
              + "JOIN tblEngine "
              + "ON tblEngine.EngineID = tblCarEngines.EngineID WHERE ";
      break;

    case "2":    // compare Fuel Consumption
      sCaption = "Fuel consumption (mpg) at a steady speed (mph) of:";
      sResult = "SELECT Caption = Model + ' ' + EngineName, "
              + "[30] = Fuel30, [40] = Fuel40, [50] = Fuel50, "
              + "[60] = Fuel60, [70] = Fuel70, [80] = Fuel80, "
              + "[90] = Fuel90, [100] = Fuel100 "
              + "FROM (tblCar JOIN tblCarEngines "
              + "ON tblCar.CarID = tblCarEngines.CarID) "
              + "JOIN tblEngine "
              + "ON tblEngine.EngineID = tblCarEngines.EngineID WHERE ";
      break;
    }

  // create WHERE clause section for each value in query string
  // split list into an array, the extract each value
  String[] aList = sModelList.Split(new Char[]{'*'});
  String sModel, sEngine;
  foreach (String sItem in aList) {
    sModel = sItem.Substring(0, sItem.IndexOf(" "));
    sEngine = sItem.Substring(sItem.IndexOf(" ") + 1);
    sResult += "(Model = '" + sModel + "' AND EngineName = '"
            + sEngine + "') OR ";
  }

  // remove final "OR" from string
  sResult = sResult.Substring(0, sResult.Length - 4);

  // add ORDER BY clause and return result
  return sResult + " ORDER BY Model, EngineName";

}
// -------------------------------------------------------------------
</script>