I have the following piece of code:
dim selectRange as Range
Set selectRange = Application.InputBox(\"Select your range\", \"Hello\", , , , , , 8)
I have found that checking for the "Object required" error that you mentioned is one way of handling a cancel.
On Error Resume Next
dim selectRange as Range
' InputBox will prevent invalid ranges from being submitted when set to Type:=8.
Set selectRange = Application.InputBox("Select your range", "Hello", , , , , , 8)
' Check for cancel: "Object required".
If Err.Number = 424 Then
' Cancel.
Exit Sub
End If
On Error GoTo 0