I'm currently generating Excel-documents using the Office Object Model. I have a problem with editing charts. In a template file I got a bar-chart which uses the following source:
2008 2009 2010
A 10% 25% 15%
B 20% 25% 35%
C 30% 25% 45%
D 40% 25% 5%
The chart has the following formula: =sheet2!$A$1:$D$5
When for example the column '2009' is empty, I don't want to show the bar in the chart. So I want to change the formula to something like: =sheet2!A$1:D$5;sheet2!C$1:C$5
I know there is a method setSourceData, but I need to get the current formula or range first.
My question is; How can I get the chart formula? Or maybe there is another way to do what I want?
I also tried something with dynamic ranges in Excel, but this seems to only work with columns that are added or removed from the end of the range, not in the middle like column '2009'.
I made the following code to solve my problem. It rebuilds all the existings series formulas. This won't work for all possible charts, but it does for the ones I currently have. In the future I'll probably look at it again and try to improve it. Suggestions to the code below are welcome.
(sorry for the lack of code comments)
foreach (Excel.ChartObject chart in (Excel.ChartObjects)sheet.ChartObjects(Type.Missing))
{
IDictionary<int, Boolean> colHasValues = new Dictionary<int, Boolean>();
ArrayList seriesFormulas = new ArrayList();
foreach (Excel.Series series in (Excel.SeriesCollection)chart.Chart.SeriesCollection(Type.Missing))
{
seriesFormulas.Add(series.Formula);
Array sValues = (Array)series.Values;
int i = 1;
foreach (Object o in sValues)
{
if(!colHasValues.Keys.Contains(i)) colHasValues.Add(i, false);
if (o != null)
{
colHasValues[i] = true;
}
i++;
}
}
if (!colHasValues.Values.Contains(true))
{
chart.Delete();
}
else if (colHasValues.Values.Contains(false) && seriesFormulas.Count > 1)
{
ArrayList newSeriesFormulas = new ArrayList();
foreach (String formula in seriesFormulas)
{
String[] formulaBits = formula.Split(";".ToCharArray());
if (formulaBits.Length == 4)
{
for (int arrNr = 1; arrNr <= 2; arrNr++)
{ //1 = XValues, 2 = Values
int indexFirstChar = formulaBits[arrNr].IndexOf(':');
int indexLastChar = formulaBits[arrNr].LastIndexOf('$', indexFirstChar) + 1;
String firstRow = formulaBits[arrNr].Substring(indexLastChar, indexFirstChar - indexLastChar);
String firstColumn = formulaBits[arrNr].Substring(indexLastChar - 2, 1);
formulaBits[arrNr] = "";
foreach (KeyValuePair<int, Boolean> cat in colHasValues)
{
if (cat.Value == true)
{
formulaBits[arrNr] += "overzichten!$" + getExcelColumnName((getExcelColumnNumber(firstColumn) + cat.Key - 1)) + "$" + firstRow + ":$" + getExcelColumnName((getExcelColumnNumber(firstColumn) + cat.Key - 1)) + "$" + firstRow + ";";
}
}
formulaBits[arrNr] = formulaBits[arrNr].TrimEnd(";".ToCharArray());
if (formulaBits[arrNr].Contains(';'))
{
formulaBits[arrNr] = "(" + formulaBits[arrNr] + ")";
}
}
newSeriesFormulas.Add(String.Join(";", formulaBits));
}
}
int seriesid = 0;
foreach (Excel.Series series in (Excel.SeriesCollection)chart.Chart.SeriesCollection(Type.Missing))
{
series.Formula = newSeriesFormulas[seriesid].ToString();
seriesid++;
}
}
}