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I had this code working a few days ago, but forgot to save the working copy. It took me 4 weeks just to find this answer and would not like to take that much time again, so...

Everything here works, except the objWorkBook lines, which return the error: "Variable 'objWorkBook' is used before it has been assigned a value. A null reference exception could result at runtime."

Any suggestions?

Dim objExcel As Excel.Application = System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application")
Dim objWorkBook As Excel.Workbook

Dim totalWorkBooks As Integer = objExcel.Workbooks.Count
MsgBox(totalWorkBooks & " is Number of Open Workbooks")

Dim ActiveBookIndex As Integer = objExcel.ActiveWindow.Index
MsgBox(ActiveBookIndex & " is Active Window Index")

Dim FullName As String = objWorkBook.FullName
MsgBox(FullName & " is FullName")

Dim OnlyName As String = objWorkBook.Name
MsgBox(OnlyName & " is Name without the Path")

I forgot what Value I had assigned.

My objective is to compare an open Excel Workbook name with one in a known location so that if they match, my program can proceed. I need the code above so I can compare it to the following code in an If-Then so that my program can proceed.

Dim dir As String = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)
Dim FullFileName As String = dir & "\My_File_Name.xlsx"

On a positive note, I pieced together A solution, even though it's not the answer I was looking for.... 

Dim p() As Process = System.Diagnostics.Process.GetProcessesByName("Excel")
Dim Title As String = p(0).MainWindowTitle
Dim dir As String = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)
        Dim FullFileName As String = dir & "\" & Replace(Title, "Microsoft Excel - ", "") & ".xlsx"

MsgBox(dir)
MsgBox(Title)
MsgBox(FullFileName)

This will work for now, but I would like to solve it the other way.

4

1 回答 1

1

换行

Dim objWorkBook As Excel.Workbook

至

Dim objWorkBook As Excel.Workbook = Nothing

objWorkBook在您尝试在行中使用它之前，您的对象也没有分配给任何东西Dim FullName As String = objWorkBook.FullName

这是你正在尝试的吗？

Imports Excel = Microsoft.Office.Interop.Excel

Public Class Form1
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim objExcel As Excel.Application = System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application")
        Dim objWorkBook As Excel.Workbook

        Dim totalWorkBooks As Integer = objExcel.Workbooks.Count
        MsgBox (totalWorkBooks & " is Number of Open Workbooks")

        Dim ActiveBookIndex As Integer = objExcel.ActiveWindow.Index
        MsgBox (ActiveBookIndex & " is Active Window Index")

        '~~> Set the workbook to say first workbook.
        '~~> You can use a loop here as well to loop through 
        '~~> the workbooks count
        objWorkBook = objExcel.Workbooks(1)

        Dim FullName As String = objWorkBook.FullName
        MsgBox (FullName & " is FullName")

        Dim OnlyName As String = objWorkBook.Name
        MsgBox (OnlyName & " is Name without the Path")

        '
        '~~> Rest of the code
        '
    End Sub
End Class

编辑：评论的跟进

但是假设我已经打开了 9 个工作簿，我如何让我的应用程序在它们之间建立索引、操作、切换......而不提前知道完整路径和文件名？

Imports Excel = Microsoft.Office.Interop.Excel

Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim objExcel As Excel.Application = System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application")
        Dim objWorkBook As Excel.Workbook = Nothing
        Dim FullName As String = ""
        Dim OnlyName As String = ""

        Dim totalWorkBooks As Integer = objExcel.Workbooks.Count
        MsgBox (totalWorkBooks & " is Number of Open Workbooks")

        For i As Integer = 1 To totalWorkBooks
            objWorkBook = objExcel.Workbooks(i)

            With objWorkBook
                FullName = .FullName
                OnlyName = .Name

                MessageBox.Show (FullName & " is FullName and " & OnlyName & " is Name without the Path")

                '
                '~~> Rest of the code here to manipulate the workbook. For example
                ' objWorkBook.Sheets(1).Range("A1").Value = "Blah Blah"
                '

            End With
        Next i

        releaseObject (objExcel)
        releaseObject (objWorkBook)
    End Sub

    '~~> Release the objects
    Private Sub releaseObject(ByVal obj As Object)
        Try
            System.Runtime.InteropServices.Marshal.ReleaseComObject (obj)
            obj = Nothing
        Catch ex As Exception
            obj = Nothing
        Finally
            GC.Collect()
        End Try
    End Sub
End Class
于 2013-11-11T09:53:32.747 回答