How to calculate rdlc tablix rows sum and rows count in textboxes

Question

I have tablix named tablix2 and have 3 columns ,I want to calculate rows sum and count in 2 textboxes out of the tablix scope, I try this expression.

=RowNumber("Tablix2")

And

=CountRows("Tablix2")

And

=Count(Fields!ID.Value,"Tablix2")

Its always show me this error message:

The Value expression for the text box ‘Textbox7’ has a scope parameter that is not valid for an aggregate function. The scope parameter must be set to a string constant that is equal to either the name of a containing group, the name of a containing data region, or the name of a dataset.

Answer 1

You need to use a scope name which is valid. If you're outside of the tablix then you should use dataset scope probably.

Try something like

=Count(Fields!ID.Value,"DatasetName") or

=Sum(Fields!ID.Value,"DatasetName")

Answer 2

Right Click on the tablix on the last row in the group (you have to do this in the "handle" area to the far left because you get a different right click menu if you click in the row area), then choose "Insert Row" and "Outside Group Below." Merge cells as necessary and drag a textbox into the one you want to put the value. Then put =Count(Fields!ID.Value) for the expression inside the textbox to get the group count, for example.

This worked for me, but I agree it is far from intuitive and doesn't appear to be documented well anywhere for what should be such a basic feature in a reportwriter.