在.NET中正确关闭Excel互操作应用程序的问题

Question

我在使用.net中与office excel的interop时遇到了问题。我尝试了很多方法来关闭我在程序中创建的excel应用、工作簿和工作表，但我总是发现excel.exe仍然在内存中。我甚至尝试过强制垃圾回收，请帮忙。

这是我用来实例化所有内容的代码：

Private mExcelApp As Microsoft.Office.Interop.Excel.ApplicationClass
Private mWorkBook As Microsoft.Office.Interop.Excel.Workbook
Private mWorkSheet As Microsoft.Office.Interop.Excel.Worksheet


   Public Sub Execute()

    mExcelApp = New Microsoft.Office.Interop.Excel.ApplicationClass
     If mFirstPass Then
         mWorkBook = mExcelApp.Workbooks.Add()
         mWorkSheet = CType(mWorkBook.ActiveSheet(), Microsoft.Office.Interop.Excel.Worksheet)
    Else
        mWorkBook = mExcelApp.Workbooks.Open(System.IO.Path.Combine(mFileLocation, mMTDefinition.Description & "_" & mMTDefinition.Version & ".xls"))
         mWorkSheet = CType(mWorkBook.Sheets(1), Microsoft.Office.Interop.Excel.Worksheet)
         Dim excelRange As Microsoft.Office.Interop.Excel.Range = mWorkSheet.UsedRange
         excelRange.SpecialCells(Microsoft.Office.Interop.Excel.XlCellType.xlCellTypeLastCell).Activate()
         mCurrentRow = mExcelApp.ActiveCell.Row + 1

    End If

    Here is how i try to close everything

    If mFirstPass Then
         mWorkBook.SaveAs(System.IO.Path.Combine(mFileLocation, mMTDefinition.Description & "_" & mMTDefinition.Version & ".xls"))
         mFirstPass = False
      Else
         mWorkBook.Save()
    End If
      a
    mWorkBook.Close()
    mExcelApp.Quit()

    mWorkSheet = Nothing
    mWorkBook = Nothing
    mExcelApp = Nothing
    System.GC.Collect()

- Thulani Chivandikwa

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你尝试过 for each book in mExcelApp.Workbooks: book.saved = true: next 吗？ - user69820

Answer 1

基本思路是为每个创建的COM对象调用Marshal.ReleaseComObject。

    Dim app As New Excel.Application()
    Dim workBook As Excel.Workbook = app.Workbooks.Add()
    Try

        Dim t As Int32 = 0
        ' This example is filling an excel spreadsheet using data stored in a Dictionary
        For Each key In sampleData.Keys
            t += 1
            ' Add a worksheet and dump data.
            Dim sheet As Excel.Worksheet = workBook.Worksheets.Add()
            sheet.Name = key

            ' Set columns
            For i = 1 To sampleData(key).Columns.Count
                sheet.Cells(1, i) = sampleData(key).Columns(i - 1).ColumnName
            Next

            ' Set data.
            For r = 1 To sampleData(key).Rows.Count
                For c = 1 To sampleData(key).Columns.Count
                    sheet.Cells(r + 1, c) = sampleData(key).Rows(r - 1).Item(c - 1).ToString()
                Next c
            Next r
            Marshal.ReleaseComObject(sheet)
        Next

        workBook.SaveAs("fileName.xls", Excel.XlFileFormat.xlExcel8)
        workBook.Close(SaveChanges:=False)

    Finally
        app.Quit()
        Marshal.ReleaseComObject(workbook)
        Marshal.ReleaseComObject(app)
        app = Nothing
    End Try

- Justin Largey

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非常感谢Justin，这对我非常有帮助。现在我知道如何处理未托管的COM对象了。 - Thulani Chivandikwa

Answer 2

由于Excel应用程序是一个非托管的COM对象，回收托管内存可能不起作用。我已经使用了

Marshal.ReleaseComObject(mExcelApp);

有一定的成功。

- SWeko

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我会尝试一下。非常感谢。 - Thulani Chivandikwa