Why doesn't this work?

Sub showall()
'
Dim sh As Worksheet
'
Application.Calculation = xlManual
For Each sh In ThisWorkbook.Worksheets
sh.Activate
ActiveSheet.ShowAllData
Next sh
Application.Calculation = xlAutomatic
End Sub

I recorded a macro on a single sheet to show all data and it returned
"activesheet.showalldata". What I'm trying to do is to scroll through every
worksheet in a workbook and show all if there is a filter on the page.