Detect whether Excel workbook is already open [closed]

Answer 1

Checkout this function

'********************************************************************************************************************************************************************************
'Function Name                     : IsWorkBookOpen(ByVal OWB As String)
'Function Description             : Function to check whether specified workbook is open
'Data Parameters                  : OWB:- Specify name or path to the workbook. eg: "Book1.xlsx" or "C:\Users\Kannan.S\Desktop\Book1.xlsm"

'********************************************************************************************************************************************************************************
Function IsWorkBookOpen(ByVal OWB As String) As Boolean
    IsWorkBookOpen = False
    Dim WB As Excel.Workbook
    Dim WBName As String
    Dim WBPath As String
    Err.Clear
    On Error Resume Next
    OWBArray = Split(OWB, Application.PathSeparator)
    Set WB = Application.Workbooks(OWBArray(UBound(OWBArray)))
    WBName = OWBArray(UBound(OWBArray))
    WBPath = WB.Path & Application.PathSeparator & WBName
    If Not WB Is Nothing Then
        If UBound(OWBArray) > 0 Then
            If LCase(WBPath) = LCase(OWB) Then IsWorkBookOpen = True
        Else
            IsWorkBookOpen = True
        End If
    End If
    Err.Clear
End Function