How to make a powerpoint chart reflect changes to its data source?

I'm using openxml sdk 2 to change the excel data from a chart on a powerpoint file (2007). I can change the data but when I open the changed file on powerpoint, the chart shows the original data. Only when I choose "Edit data", it shows the excel sheet with the correct data and the chart is updated. How can I make the chart reflect the underlying cha开发者_如何学JAVAnges?

It sounds as though you have an embedded chart rather than a linked one. With an embedded chart, the chart and the spreadsheet behind it are part of the host document (PowerPoint file in this case). There's no connection to the original file as there would be with a linked chart or spreadsheet.