Excel進程繼續運行

我從按鈕單擊事件調用以下方法將數據表導出爲excel。導出完成後，excel應用程序對象退出，釋放並分配爲空。但實際上它並沒有得到發佈，並且除非整個應用程序關閉，否則它們將保持活動狀態所以每次點擊按鈕導出時，一個新的Excel應用程序對象都會繼續運行。我該如何解決這個問題？請幫忙。問候。Excel進程繼續運行

如果不使用以下方法中的兩行，則不會出現該問題。但我不能忽略它們，因爲它們確實是需要的。檢查*標記的行。

''' <summary> 
''' Exports data from a datatable to excel. 
''' </summary> 
Friend Shared Sub ExportToExcel(ByVal dtbl As DataTable) 
    Dim exa As Excel.Application = Nothing 
    Dim wkb As Excel.Workbook = Nothing 
    Dim wks As Excel.Worksheet = Nothing 
    Dim intColIndex, intRowIndex As Integer 
    intColIndex = 0 : intRowIndex = 2 

    Try 
     exa = New Excel.Application 
     exa.SheetsInNewWorkbook = 1 
     wkb = exa.Workbooks.Add 
     wks = wkb.ActiveSheet 

     For intColIndex = 1 To dtbl.Columns.Count 
      wks.Cells(1, intColIndex) = dtbl.Columns(intColIndex - 1).ColumnName 
     Next 

     For Each row As DataRow In dtbl.Rows 
      For intColIndex = 1 To dtbl.Columns.Count 
       wks.Cells(intRowIndex, intColIndex) = row(intColIndex - 1) 
      Next 

      intRowIndex += 1 
     Next 

     For intColIndex = 1 To dtbl.Columns.Count 
      wks.Range(wks.Cells(1, intColIndex), wks.Cells(1, intColIndex)).Font.Bold = True 
      wks.Range(wks.Cells(1, intColIndex), wks.Cells(1, intColIndex)).Font.Underline = True 
     Next 

    '***** The problem doesn't occur if the following two lines are not used ***** 
     wks.Range(wks.Cells(1, 1), wks.Cells(dtbl.Rows.Count + 1, dtbl.Columns.Count)).Columns.WrapText = False 
     wks.Range(wks.Cells(1, 1), wks.Cells(dtbl.Rows.Count + 1, dtbl.Columns.Count)).Columns.AutoFit() 
    '***************************************************************************** 

     exa.Visible = True 
     exa.UserControl = True 

     If Not exa Is Nothing Then exa.Quit() 
     System.Runtime.InteropServices.Marshal.ReleaseComObject(wks) 
     wks = Nothing 
     System.Runtime.InteropServices.Marshal.ReleaseComObject(wkb) 
     wkb = Nothing 
     System.Runtime.InteropServices.Marshal.ReleaseComObject(exa) 
     exa = Nothing 
    Catch ex As Exception 
     wks = Nothing 
     wkb = Nothing 
     exa = Nothing 
     MsgBox("The following error has occurred:" & vbCrLf & ex.Message, MsgBoxStyle.Critical, "Error") 
    Finally 
     GC.Collect() 
    End Try 
End Sub

來源

2011-04-15 priyamtheone