在 .net 中正确关闭 Excel 互操作应用程序时出现问题

Question

我在 .net 中使用与 Office excel 的互操作时遇到问题。我已经尝试了很多方法来关闭我创建的在程序中使用的 Excel 应用程序、工作簿和工作表，但我总是注意到 excel.exe 仍在内存中。我什至尝试过强制垃圾收集器，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()

Answer 1

基本思想是为创建的每个 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

Answer 2

由于 Excel 应用程序是非托管 COM 对象，因此回收托管内存可能不起作用。我已经使用

Marshal.ReleaseComObject(mExcelApp);

并取得了一些成功。