Excel进程继续运行(.Net Framework 3.5，VS.Net 2008，VB.Net 2008). [英] Excel process continues running (.Net Framework 3.5, VS.Net 2008, VB.Net 2008).

问题描述

我正在从按钮单击事件中调用以下方法，以将数据表导出到excel.导出完成后，将退出excel应用程序对象，将其释放，然后将其分配为空.但实际上，除非关闭整个应用程序，否则它不会被释放并保持活动状态.因此，每次单击按钮进行导出时，新的excel应用程序对象都会继续运行.我该如何解决?请帮忙.问候.

如果未使用下面方法中的两行，则不会发生此问题.但是我不能忽略它们，因为它们确实是必需的.检查*标记的行.

Hi, I''m calling the following method from a button click event to export a datatable to excel. After the export is completed, the excel application object is quit, released and assigned to nothing. But in reality it''s not getting released and stays active unless the entire application is closed. So every time the button is clicked for export, a new excel application object keeps on running. How can I solve this? Please help. Regards.

The problem doesn''t occur if two of the lines from the method below are not used. But I can''t omit them as they are really needed. Check the * marked lines.

'''''' <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

推荐答案

首先关闭/保存所有Excel对象:

First close/save all your Excel objects:

//wks.Save() is optional
wks.Close()
//wkb.Save() is optional
wkb.Close()

Marshal.ReleaseComObject(wks)
Marshal.ReleaseComObject(wkb)

wks = Nothing
wkb = Nothing

exa.Quit()
Marshal.ReleaseComObject(exa)
exa = Nothing

GC.Collect()
GC.WaitForPendingFinalizers()

那应该可以解决的！

问候，

-MRB

That should do the trick!

Regards,

-MRB

看看 ^ ]类似问题

我包括执行流程清理的ExcelWrapper类的代码

我还解释了Excel实例为什么挂起的一个常见原因...通过按其集合访问属性来偶然增加COM引用.


我知道它在C#中，尽管您可以很容易地移植到VB

Have a look at my answer[^] to a similar issue

I included code for an ExcelWrapper class that performs process cleanup

I''ve also explained a common reason for why Excel instances hang around...accidentally incrementing COM references by accessing properties by their collections.


I know it''s in C#, you could port to VB quite easily though

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