SSRS Multi Value Parameter. Check whether “Select All” is selected

Question

I have a multi value parameter in my SSRS Report. I want to find out whether (Select All) is checked in that parameter.

In other words, whether all the values in th

Answer 1

The easy way will be to count the number of the selected parameters and compare them to the dataset

=IIF(Parameters!company_number.Count = CountRows("Dataset1"), True, False)