调用退出后应用程序未退出

我有一个小问题，我似乎无法弄清楚。我正在将 DataGridView （它的内容）保存到 xls 文件中。我这样做没有任何问题，除了在我的任务管理器中它仍然显示它正在运行。我已致电：

  xlApp.Application.Quit() 

这被声明为：

  Dim xlApp As New excel.Application

这似乎不起作用，但这与我让用户选择将其导出到 Word 文档时退出的方式相同。我不确定我哪里错了......

这是我的完整代码

Imports Word = Microsoft.Office.Interop.Word
 Imports Excel = Microsoft.Office.Interop.Excel

 Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    For x As Integer = 1 To 3500
        DataGridView1.Rows.Add(New Object() {"r" & x.ToString & "c1", "r" & x.ToString & "c2", "r" & x.ToString & "c3", "r" & x.ToString & "c4", "r" & x.ToString & "c5"})
    Next
End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    exportToWord (DataGridView1)
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim xlApp As New Excel.Application
    Dim xlWorkBook As Excel.Workbook
    Dim xlWorkSheet As Excel.Worksheet
    'Dim misValue As Object = System.Reflection.Missing.Value


    xlWorkBook = xlApp.Workbooks.Add
    xlWorkSheet = DirectCast(xlWorkBook.Sheets("sheet1"), Excel.Worksheet)

    xlApp.Visible = True

    Dim headers = (From ch In DataGridView1.Columns _
                  Let header = DirectCast(DirectCast(ch, DataGridViewColumn).HeaderCell, DataGridViewColumnHeaderCell) _
                  Select header.Value).ToArray()
    Dim headerText() As String = Array.ConvertAll(headers, Function(v) v.ToString)

    Dim items() = (From r In DataGridView1.Rows _
          Let row = DirectCast(r, DataGridViewRow) _
          Where Not row.IsNewRow _
          Select (From cell In row.Cells _
              Let c = DirectCast(cell, DataGridViewCell) _
              Select c.Value).ToArray()).ToArray()

    Dim table As String = String.Join(vbTab, headerText) & Environment.NewLine
    For Each a In items
        Dim t() As String = Array.ConvertAll(a, Function(v) v.ToString)
        table &= String.Join(vbTab, t) & Environment.NewLine
    Next
    table = table.TrimEnd(CChar(Environment.NewLine))
    Clipboard.SetText (table)

    Dim alphabet() As Char = "abcdefghijklmnopqrstuvwxyz".ToUpper.ToCharArray

    Dim range As excel.Range = xlWorkSheet.Range("B2:" & alphabet(headerText.Length) & (items.Length + 2).ToString)

    range.Select()
    xlWorkSheet.Paste()

    range.Borders(Excel.XlBordersIndex.xlDiagonalDown).LineStyle = Excel.XlLineStyle.xlLineStyleNone
    range.Borders(Excel.XlBordersIndex.xlDiagonalUp).LineStyle = Excel.XlLineStyle.xlLineStyleNone
    With range.Borders(Excel.XlBordersIndex.xlEdgeLeft)
        .LineStyle = Excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = Excel.XlBorderWeight.xlMedium
    End With
    With range.Borders(Excel.XlBordersIndex.xlEdgeTop)
        .LineStyle = Excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = Excel.XlBorderWeight.xlMedium
    End With
    With range.Borders(Excel.XlBordersIndex.xlEdgeBottom)
        .LineStyle = Excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = Excel.XlBorderWeight.xlMedium
    End With
    With range.Borders(Excel.XlBordersIndex.xlEdgeRight)
        .LineStyle = Excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = Excel.XlBorderWeight.xlMedium
    End With
    With range.Borders(Excel.XlBordersIndex.xlInsideVertical)
        .LineStyle = Excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = Excel.XlBorderWeight.xlThin
    End With
    With range.Borders(Excel.XlBordersIndex.xlInsideHorizontal)
        .LineStyle = Excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = Excel.XlBorderWeight.xlThin
    End With

    'xlApp.Visible = True

    xlWorkBook.SaveAs("C:\Users\CoDeXeR\Desktop\Word1.xls", True)
    xlWorkBook.Close()
    xlApp.Application.Quit()

    ReleaseObject(xlWorkSheet) '<~~~ Added as per comment from deleted post
    ReleaseObject (xlWorkBook)
    ReleaseObject (xlApp)


End Sub

Public Sub exportToWord(ByVal dgv As DataGridView)
    ' Create Word Application
    Dim oWord As Word.Application = DirectCast(CreateObject("Word.Application"), Word.Application)

    ' Create new word document
    Dim oDoc As Word.Document = oWord.Documents.Add()


    Dim headers = (From ch In dgv.Columns _
                  Let header = DirectCast(DirectCast(ch, DataGridViewColumn).HeaderCell, DataGridViewColumnHeaderCell) _
                  Select header.Value).ToArray()
    Dim headerText() As String = Array.ConvertAll(headers, Function(v) v.ToString)

    Dim items() = (From r In dgv.Rows _
          Let row = DirectCast(r, DataGridViewRow) _
          Where Not row.IsNewRow _
          Select (From cell In row.Cells _
              Let c = DirectCast(cell, DataGridViewCell) _
              Select c.Value).ToArray()).ToArray()

    Dim table As String = String.Join(vbTab, headerText) & Environment.NewLine
    For Each a In items
        Dim t() As String = Array.ConvertAll(a, Function(v) v.ToString)
        table &= String.Join(vbTab, t) & Environment.NewLine
    Next
    table = table.TrimEnd(CChar(Environment.NewLine))
    Clipboard.SetText (table)

    Dim oTable As Word.Table = oDoc.Tables.Add(oDoc.Bookmarks.Item("\endofdoc").Range, items.Count + 1, headers.Count)

    oTable.Range.Paste()

    'make the first row bold, fs 14 + change textcolor
    oTable.Rows.Item(1).range.Font.Bold = &H98967E
    oTable.Rows.Item(1).range.Font.Size = 14
    oTable.Rows.Item(1).range.Font.Color = Word.WdColor.wdColorWhite

    'change backcolor of first row
    oTable.Rows.Item(1).range.Shading.Texture = Word.WdTextureIndex.wdTextureNone
    oTable.Rows.Item(1).range.Shading.ForegroundPatternColor = Word.WdColor.wdColorAutomatic
    oTable.Rows.Item(1).range.Shading.BackgroundPatternColor = Word.WdColor.wdColorLightBlue

    ''set table borders
    'With oTable.Range.Tables(1)
    '    With .Borders(Word.WdBorderType.wdBorderLeft)
    '        .LineStyle = Word.WdLineStyle.wdLineStyleSingle
    '        .LineWidth = Word.WdLineWidth.wdLineWidth100pt
    '        .Color = Word.WdColor.wdColorAutomatic
    '    End With
    '    With .Borders(Word.WdBorderType.wdBorderRight)
    '        .LineStyle = Word.WdLineStyle.wdLineStyleSingle
    '        .LineWidth = Word.WdLineWidth.wdLineWidth100pt
    '        .Color = Word.WdColor.wdColorAutomatic
    '    End With
    '    With .Borders(Word.WdBorderType.wdBorderTop)
    '        .LineStyle = Word.WdLineStyle.wdLineStyleSingle
    '        .LineWidth = Word.WdLineWidth.wdLineWidth100pt
    '        .Color = Word.WdColor.wdColorAutomatic
    '    End With
    '    With .Borders(Word.WdBorderType.wdBorderBottom)
    '        .LineStyle = Word.WdLineStyle.wdLineStyleSingle
    '        .LineWidth = Word.WdLineWidth.wdLineWidth100pt
    '        .Color = Word.WdColor.wdColorAutomatic
    '    End With
    '    With .Borders(Word.WdBorderType.wdBorderHorizontal)
    '        .LineStyle = Word.WdLineStyle.wdLineStyleSingle
    '        .LineWidth = Word.WdLineWidth.wdLineWidth050pt
    '        .Color = Word.WdColor.wdColorAutomatic
    '    End With
    '    With .Borders(Word.WdBorderType.wdBorderVertical)
    '        .LineStyle = Word.WdLineStyle.wdLineStyleSingle
    '        .LineWidth = Word.WdLineWidth.wdLineWidth050pt
    '        .Color = Word.WdColor.wdColorAutomatic
    '    End With
    '    .Borders(Word.WdBorderType.wdBorderDiagonalDown).LineStyle = Word.WdLineStyle.wdLineStyleNone
    '    .Borders(Word.WdBorderType.wdBorderDiagonalUp).LineStyle = Word.WdLineStyle.wdLineStyleNone
    '    .Borders.Shadow = False
    'End With
    ' Save this word document
    oDoc.SaveAs("C:\Users\CoDeXeR\Desktop\Word1.doc", True)
    oDoc.Close()
    oWord.Application.Quit()
    'oWord.Visible = True

End Sub

Public Sub exportToExcel(ByVal dgv As DataGridView)

End Sub

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

只是打电话.Quit()不会从内存中删除应用程序。完成编码后关闭对象非常重要。这确保了所有对象都被正确释放并且内存中没有任何内容。

看这个例子

Imports Excel = Microsoft.Office.Interop.Excel
 
Public Class Form1
    '~~> Define your Excel Objects
    Dim xlApp As New Excel.Application
    Dim xlWorkBook As Excel.Workbook
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '~~> Add a New Workbook
        xlWorkBook = xlApp.Workbooks.Add
 
        '~~> Display Excel
        xlApp.Visible = True
 
        '~~> Do some stuff Here
 
        '~~> Save the file
        xlWorkBook.SaveAs(Filename:="C:\Tutorial\SampleNew.xlsx", FileFormat:=51)
 
        '~~> Close the File
        xlWorkBook.Close()
 
        '~~> Quit the Excel Application
        xlApp.Quit()
 
        '~~> Clean Up
        releaseObject (xlApp)
        releaseObject (xlWorkBook)
    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
 
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Me.Close()
    End Sub
End Class

另外值得一提的是2 点规则 http://www.siddharthrout.com/2012/08/06/vb-net-two-dot-rule-when-working-with-office-applications-2/.

如果您喜欢从 VB.Net 自动化 Excel 那么您可能还想看看这个link http://www.siddharthrout.com/vb-dot-net-and-excel/.

FOLLOWUP

问题在于我上面提到的 2 DOT 规则。当您使用 2 DOT 规则时（例如：Excel.XlBordersIndex.xlDiagonalDown）那么你必须使用以下方法进行垃圾收集GC.Collect()。所以你需要做的就是添加这部分

    Finally
        GC.Collect()

in the Private Sub ReleaseObject(ByVal obj As Object)

Private Sub ReleaseObject(ByVal obj As Object)
    Try
        Dim intRel As Integer = 0
        Do
            intRel = System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
        Loop While intRel > 0
        MsgBox("Final Released obj # " & intRel)
    Catch ex As Exception
        MsgBox("Error releasing object" & ex.ToString)
        obj = Nothing
    Finally
        GC.Collect()
    End Try
End Sub

最终代码

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim xlApp As New excel.Application
    Dim xlWorkBook As excel.Workbook
    Dim xlWorkSheet As excel.Worksheet
    Dim xlRange As excel.Range
    'Dim misValue As Object = System.Reflection.Missing.Value

    xlWorkBook = xlApp.Workbooks.Add
    xlWorkSheet = DirectCast(xlWorkBook.Sheets("sheet1"), excel.Worksheet)

    xlApp.Visible = True

    Dim headers = (From ch In DataGridView1.Columns _
                  Let header = DirectCast(DirectCast(ch, DataGridViewColumn).HeaderCell, DataGridViewColumnHeaderCell) _
                  Select header.Value).ToArray()
    Dim headerText() As String = Array.ConvertAll(headers, Function(v) v.ToString)

    Dim items() = (From r In DataGridView1.Rows _
          Let row = DirectCast(r, DataGridViewRow) _
          Where Not row.IsNewRow _
          Select (From cell In row.Cells _
              Let c = DirectCast(cell, DataGridViewCell) _
              Select c.Value).ToArray()).ToArray()

    Dim table As String = String.Join(vbTab, headerText) & Environment.NewLine
    For Each a In items
        Dim t() As String = Array.ConvertAll(a, Function(v) v.ToString)
        table &= String.Join(vbTab, t) & Environment.NewLine
    Next
    table = table.TrimEnd(CChar(Environment.NewLine))
    Clipboard.SetText(table)

    Dim alphabet() As Char = "abcdefghijklmnopqrstuvwxyz".ToUpper.ToCharArray

    xlRange = xlWorkSheet.Range("B2:" & alphabet(headerText.Length) & (items.Length + 2).ToString)

    xlRange.Select()
    xlWorkSheet.Paste()

    xlRange.Borders(excel.XlBordersIndex.xlDiagonalDown).LineStyle = excel.XlLineStyle.xlLineStyleNone
    xlRange.Borders(excel.XlBordersIndex.xlDiagonalUp).LineStyle = excel.XlLineStyle.xlLineStyleNone

    With xlRange.Borders(excel.XlBordersIndex.xlEdgeLeft)
        .LineStyle = excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = excel.XlBorderWeight.xlMedium
    End With
    With xlRange.Borders(excel.XlBordersIndex.xlEdgeTop)
        .LineStyle = excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = excel.XlBorderWeight.xlMedium
    End With
    With xlRange.Borders(excel.XlBordersIndex.xlEdgeBottom)
        .LineStyle = excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = excel.XlBorderWeight.xlMedium
    End With
    With xlRange.Borders(excel.XlBordersIndex.xlEdgeRight)
        .LineStyle = excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = excel.XlBorderWeight.xlMedium
    End With
    With xlRange.Borders(excel.XlBordersIndex.xlInsideVertical)
        .LineStyle = excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = excel.XlBorderWeight.xlThin
    End With
    With xlRange.Borders(excel.XlBordersIndex.xlInsideHorizontal)
        .LineStyle = excel.XlLineStyle.xlContinuous
        .ColorIndex = 1 'black
        .TintAndShade = 0
        .Weight = excel.XlBorderWeight.xlThin
    End With

    xlWorkBook.SaveAs(Filename:="C:\Users\Siddharth Rout\Desktop\Word1.xls", FileFormat:=56)
    xlWorkBook.Close()
    xlApp.Quit()

    ReleaseObject(xlRange)
    ReleaseObject(xlWorkSheet)
    ReleaseObject(xlWorkBook)
    ReleaseObject(xlApp)
End Sub


Private Sub ReleaseObject(ByVal obj As Object)
    Try
        Dim intRel As Integer = 0
        Do
            intRel = System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
        Loop While intRel > 0
        MsgBox("Final Released obj # " & intRel)
    Catch ex As Exception
        MsgBox("Error releasing object" & ex.ToString)
        obj = Nothing
    Finally
        GC.Collect()
    End Try
End Sub