VB导出excel失败后，进程excel.exe不能自动关闭！急！

Dim conn As New ADODB.Connection
Dim rs As New ADODB.Recordset
Dim sql As String
Dim provider As String
Dim datasource As String
Dim Irow, Icol As Integer
  Dim Irowcount, Icolcount As Integer
  Dim Fieldlen()
  Dim xlApp As excel.Application
  Dim xlBook As excel.Workbook
  Dim xlSheet As excel.Worksheet

  Set xlApp = CreateObject("Excel.Application")
  Set xlBook = xlApp.Workbooks.Add
  Set xlSheet = xlBook.Worksheets(1)

provider = "provider=Microsoft.jet.oledb.4.0"
datasource = "data source=" & App.Path & "\图书管理数据.mdb"
conn.Open provider & ";" & datasource
sql = "select * from 借阅信息  where 还书日期 is not null"
rs.Open sql, conn, adOpenKeyset, adLockOptimistic

If rs.RecordCount = 0 Then
    MsgBox "借阅信息为空！", vbOKOnly + vbExclamation
   rs.Close
   xlBook.Close
  Set xlApp = Nothing
  Set xlBook = Nothing
  Set xlSheet = Nothing
  Exit Sub
End If
  Irowcount = rs.RecordCount
  Icolcount = rs.Fields.Count

  ReDim Fieldlen(Icolcount)
   rs.MoveFirst

   '设置单元格式
xlSheet.Cells.Select
Selection.NumberFormatLocal = "@"
'开始插入数据
  For Irow = 1 To Irowcount + 1
   For Icol = 1 To Icolcount
          Select Case Irow
          Case 1
          xlSheet.Cells(Irow, Icol).Value = rs.Fields(Icol - 1).Name
          Case 2

          If IsNull(rs.Fields(Icol - 1)) = True Then
            Fieldlen(Icol) = LenB(rs.Fields(Icol - 1).Name)

         Else
            Fieldlen(Icol) = LenB(rs.Fields(Icol - 1))
          End If
           xlSheet.Columns(Icol).ColumnWidth = CStr(Fieldlen(Icol))

          xlSheet.Cells(Irow, Icol).Value = CStr(rs.Fields(Icol - 1))

          Case Else
          Fieldlen1 = LenB(rs.Fields(Icol - 1))

          If Fieldlen(Icol) < Fieldlen1 Then
          xlSheet.Columns(Icol).ColumnWidth = Fieldlen1

          Fieldlen(Icol) = Fieldlen1

          Else
           xlSheet.Columns(Icol).ColumnWidth = CStr(Fieldlen(Icol))
          End If

          xlSheet.Cells(Irow, Icol).Value = CStr(rs.Fields(Icol - 1) & " ")
          End Select
  Next

  Next


xlSheet.Range(xlSheet.Cells(1, 1), xlSheet.Cells(1, Icol - 1)).Font.Name = "黑体"

xlSheet.Range(xlSheet.Cells(1, 1), xlSheet.Cells(1, Icol - 1)).Font.Bold = True

xlSheet.Range(xlSheet.Cells(1, 1), xlSheet.Cells(Irow, Icol - 1)).Borders.LineStyle = xlContinuous

xlApp.Visible = True

  xlBook.Save
  Set xlApp = Nothing
  Set xlBook = Nothing
  Set xlSheet = Nothing
  rs.Close
Erro:
If Err.Number <> 0 Then
MsgBox "借阅信息导出失败", vbOKOnly + vbExclamation
End If

导出失败后！进程就能关掉了！还有导出一次成功后，第二次就报错为变量未设置！ --------------------编程问答-------------------- 加一个错误处理语句，加上一个Set XXX＝Nothing语句。 --------------------编程问答-------------------- Erro:
If Err.Number <> 0 Then
MsgBox "借阅信息导出失败", vbOKOnly + vbExclamation
End If

==>

Erro:
If Err.Number <> 0 Then

Set xlApp = Nothing
Set xlBook = Nothing
Set xlSheet = Nothing

MsgBox "借阅信息导出失败", vbOKOnly + vbExclamation
End If --------------------编程问答-------------------- 给你个片段做参考：



.

.

.

    ' Close Excel.

    excel_app.Quit

    Set excel_app = Nothing



    MsgBox "导出成功"

    

Exit Sub



myErr:

If Err.Number = 429 Then

    Screen.MousePointer = vbDefault

    MsgBox "请先安装EXCEL!", , "导出错误"

    Exit Sub

End If

excel_app.DisplayAlerts = False 

excel_app.Quit '关闭EXCEL

excel_app.DisplayAlerts = True 

Set excel_app = Nothing

MsgBox "导出出错"

End Sub

--------------------编程问答-------------------- 学习了每天回帖即可获得10分可用分

补充：VB ,  数据库(包含打印，安装，报表)