Total in a data band

[Fabio Pagano]

In a data band i would like to display a total when the data of a field changes (in my example, the Invoice number)

Eg.

Invoice number Amount (of invoice or paied) Balance

1 1.000
-300
700

2 1.500
-400
-600
500

Can i do this in a data band (with a sum field) or must i use a group band grouping by invoice number?

Thanks.

[EDV Gradl]

I would use a group header and a group footer and a variable (MyVar) of type decimal

GroupHeader : Condition: InVoiceNumer
After Print event: this.MySum = 0;

Data Band Rendering Event: this.MySum += Data.Paid;

Group Footer :
Text component with text: Sum: {this.MyVar}