How to set group summaries values

Hello Bernardo,
To introduce this functionality you should handle the DataController's Summary.OnAfterSummary event in which you should populate values within the ASender.GroupSummaryValues array. In the attachment you will find a sample project demonstrating this approach. Please review it and inform me whether it meets your requirements.
I'm awaiting your response.
Thanks,
Stan.

Hi Stan,
Thank you for the sample project. It's very seemed to the procedure I was using before. Unfortunately, it also doesn't work.
I attached my code and a new image to this reply that I hope will help you discover this problem's cause.
So let me explain what I'm doing: I have 2 columns that link to different dataset fields but should show the second column summary values. So, I summarize both columns (using your grid's native tasks) and then overwrite the first column summary with the second column summary value. It works fine with group footer summary but not with group header summary that still shows grid's sum.
Image:
Please, compare columns named 'Custo Total' and 'Venda'
Thanks in advance

Hello Bernardo,
Thank you for the response. If I understand your task correctly it is not necessary to perform any custom calculation here. All you need is to adjust the first column's summaries so they will display summaries from the second column. This can be done as demonstrated in the attached sample.
Please try this solution and inform us of your results.
Thanks,
Stan.

Hi Stan,
The situation I explained in my last reply was just a way I found to clarify my question. I wanted you to know that even when I set the value for group summaries directly the summary that appears in group header does not reflects my changes.
I've attached another sample code (simplified) and another image to illustrate what I'm trying to explain. In my project some columns summaries values are calculations results based on previous summarized columns. So, I use the VENDA and CUSTO TOTAL columns summaries values in a function that returns values for column '%V->C' and so on… There is no field I can indicate to these default for groups columns - your last sample project is very useful for VENDA and CUSTO TOTAL columns, e.g., but it doesn't work with '%V->C' column that depends exclusively on calculations.
Maybe my function is not well constructed or there is a bug in cxGrid that prevents header groups summaries from being updated manually, so please take a careful look to the attached sample code. Hope you've understood my problem.
Best regards

Hello Bernardo,
Thank you for the sample code. I have researched it. The cause of the issue seems to be that you are not assigning a summary value for the summary item that is displayed within the group row. In your code, you are adjusting only a single summary item's value:

Delphi
ASender.GroupSummaryValues[ADataGroupIndex, ASummaryItems.IndexOfItemLink(DadosMARGEMCUSTO)] := lvResult;  

However, there should be another summary item whose Column property equals to the DadosMARGEMCUSTO column. You should find this summary item either by an index or by column, and adjust its value correspondingly.
Thanks,
Stan.

Hi Stan,
Thank you very much for your attention!
Let's see if I understood your explanation. I thought if I set a value to a GroupSummaryValues property providing a data group index and a column index I would be putting that value in group footer AND ALSO in group header; however, you are saying that I have to set group header values separately, right? Please correct me if I'm wrong…
If so, please send me a sample project because I don't know how to do that. What property should I use? How could I find the desired summary item (that's missing) by column?
Thanks