VBA: validating no empty cells in ranges before proceeding - vba

Question

I have three ranges in a sheet (rng1, rng2, rng3) where I need to make sure that rng2 and rng3 contain no blanks before proceeding with the macro.
I have tried several methods that I can find and cannot get any of them to work. Willing to try a different method if someone has suggestions.
This is me trying to count blank cells using specialcells(xlCellTypeBLanks) but something isn't working with my error handling when neither range is blank:
Dim wrk As Workbook
Dim sht As Worksheet
Dim twb As Workbook
Dim tws As Worksheet
Dim lrow As Long
Dim rng1 As Range
Dim rng2 As Range
Dim rng3 As Range
Dim finprod As Variant
Dim subprod As Variant
Application.ScreenUpdating = False
Set wrk = ActiveWorkbook
Set sht = wrk.Worksheets(1)
For Each sht In wrk.Worksheets
lrow = sht.Range("A" & Rows.Count).End(xlUp).Row
Set rng1 = sht.Range("A2:A" & lrow)
Set rng2 = sht.Range("F2:F" & lrow)
Set rng3 = sht.Range("E2:E" & lrow)
On Error GoTo Err1
If rng3.SpecialCells(xlCellTypeBlanks).Count > 0 Then
MsgBox ("Invalid item number.")
Exit Sub
End If
Err1:
On Error GoTo Err2
If rng2.SpecialCells(xlCellTypeBlanks).Count > 0 Then
MsgBox ("Missing quantity.")
Exit Sub
End If
Err2:
On Error GoTo 0
Exit For
Next sht

Answer 1

I try to avoid using goto in such way - it makes the code confusing when it gets bigger. Here is what I came up with:
Sub check_blank()
Dim sht As Worksheet
Dim twb As Workbook
Dim tws As Worksheet
Dim lrow As Long
Dim rng1 As Range
Dim rng2 As Range
Dim rng3 As Range
Dim finprod As Variant
Dim subprod As Variant
Application.ScreenUpdating = False
Set wrk = ActiveWorkbook
Set sht = wrk.Worksheets(1)
For Each sht In wrk.Worksheets
lrow = sht.Range("A" & Rows.Count).End(xlUp).Row
Set rng1 = sht.Range("A2:A" & lrow)
Set rng2 = sht.Range("F2:F" & lrow)
Set rng3 = sht.Range("E2:E" & lrow)
If Application.CountIf(rng3, "") > 0 Then
MsgBox ("Invalid item number.")
Exit Sub
End If
If Application.CountIf(rng2, "") > 0 Then
MsgBox ("Missing quantity.")
Exit Sub
End If
Next sht
End Sub

Answer 2

The Range.SpecialCells method is Nothing when there are no xlCellTypeBlanks cells available and Nothing does not have a count; not even a count of zero.
You can use the On Error Resume Next or choose a non-destructive method of determining if there are blank cells.
if cbool(application.countblank(rng2)) then
'there are zero-length string and/or blank cells
'do something
end if
The problem with the above is that the worksheet's COUNTBLANK function will count zero-length strings returned by a formula (e.g. "") as blanks when they are not truly blank.
To catch only truly blank cells the following will be True - CBool(rng2.Count - application.Countif(rng2, "<>")). Only truly blank cells will be counted and any non-zero count will be true. This avoids having to crash the environment with On Error Resume Next when there is nothing to find.