How to quit excel application from VB.NET - vb.net

Question

My program is able to retrieve data from an excel macro 2010 workbook and change contents and save changes made, all using the datagridview within VB.NET. However I'm facing a problem where the program saves but will not close. When I look at the processes in the task manager its still showing Excel 2010 as running. If anyone can help me find a way to quit this application I would greatly appreciate it!
Imports System.Data.OleDb
Imports Microsoft.Office.Interop.Excel
Imports Microsoft.Office.Interop
Imports System.IO
Public Class Form1
Dim SheetList As New ArrayList
Private excelObj As ExcelObject
Private dt As DataTable = Nothing
Dim DS As DataSet
Dim DS2 As DataSet
Dim ds3 As DataSet
Dim ds4 As DataSet
Dim ds5 As DataSet
Dim ds6 As DataSet
Dim ds7 As DataSet
Dim ds8 As DataSet
Dim ds9 As DataSet
Dim ds10 As DataSet
Dim ds11 As DataSet
Dim ds12 As DataSet
Dim ds13 As DataSet
Dim ds14 As DataSet
Dim ds15 As DataSet
Dim ds16 As DataSet
Dim ds17 As DataSet
Dim ds18 As DataSet
Dim MyCommand As OleDb.OleDbDataAdapter
Dim MyCommand2 As OleDb.OleDbDataAdapter
Dim MyCommand3 As OleDb.OleDbDataAdapter
Dim MyCommand4 As OleDb.OleDbDataAdapter
Dim MyCommand5 As OleDb.OleDbDataAdapter
Dim MyCommand6 As OleDb.OleDbDataAdapter
Dim MyCommand7 As OleDb.OleDbDataAdapter
Dim MyCommand8 As OleDb.OleDbDataAdapter
Dim MyCommand9 As OleDb.OleDbDataAdapter
Dim MyCommand10 As OleDb.OleDbDataAdapter
Dim MyCommand11 As OleDb.OleDbDataAdapter
Dim MyCommand12 As OleDb.OleDbDataAdapter
Dim MyCommand13 As OleDb.OleDbDataAdapter
Dim MyCommand14 As OleDb.OleDbDataAdapter
Dim MyCommand15 As OleDb.OleDbDataAdapter
Dim MyCommand16 As OleDb.OleDbDataAdapter
Dim MyCommand17 As OleDb.OleDbDataAdapter
Dim MyCommand18 As OleDb.OleDbDataAdapter
Dim objExcel As New Excel.Application()
Dim objWorkBook As Excel.Workbook = objExcel.Workbooks.Add
Dim objWorkSheet1 As Excel.Worksheet = objExcel.ActiveSheet
Dim objWorkSheet2 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet3 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet10 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet11 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet12 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet13 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet23 As Excel.Worksheet = objExcel.ActiveSheet
Dim objworksheet24 As Excel.Worksheet = objExcel.ActiveSheet
'<TBD make 15 more of these>
Dim MyConnection As OleDb.OleDbConnection
Dim MYDBConnection As DAO.Connection
Public MyWorkspace As DAO.Workspace
Public sizetable As DAO.Recordset
Public MyDatabase As DAO.Database
Public ReadOnly Property Excel() As ExcelObject
Get
If excelObj Is Nothing Then
excelObj = New ExcelObject(txtFilePath.Text)
End If
Return excelObj
End Get
End Property
Sub openExcelfile()
Dim dlg As New OpenFileDialog()
dlg.Filter = "Excel Macro Enabled Files|*.xlsm*|Excel Files|*.xls|Excel 2007 Files|*.xlsx|All Files|*.*"
If dlg.ShowDialog() = DialogResult.OK Then
excelObj = New ExcelObject(dlg.FileName)
txtFilePath.Text = dlg.FileName
btnRetrieve.Enabled = txtFilePath.Text.Length > 0
End If
Dim ExcelSheetName As String = ""
'open the excel workbook and create an object for it
objExcel = CreateObject("Excel.Application")
'do some exception handling on a blank txtfilepath.text
objWorkBook = objExcel.Workbooks.Open(txtFilePath.Text)
Dim i As Integer
i = 1
For Each objWorkSheets In objWorkBook.Worksheets
SheetList.Add(objWorkSheets.Name)
Select Case i
Case 4
objWorkSheet1 = objExcel.Worksheets(objWorkSheets.Name)
Case 5
objWorkSheet2 = objExcel.Worksheets(objWorkSheets.Name)
'ListBox1.Items.Add(objWorkSheets.Name)
'etc
End Select
i = i + 1
Next
End Sub
Sub Write2Excel()
Dim rowindex As Integer
Dim columnindex As Integer
For rowindex = 1 To DataGridView1.RowCount
For columnindex = 1 To DataGridView1.ColumnCount
objWorkSheet1.Cells(rowindex + 4, columnindex + 0) = DataGridView1(columnindex - 1, rowindex - 1).Value
Next
Next
'etc
End Sub
Private Sub btnBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBrowse.Click
openExcelfile()
End Sub
Sub oldretrieve()
' Dim dt As DataTable = Me.Excel.GetSchema()
' cmbTableName.DataSource = (From dr In dt.AsEnumerable() Where Not dr("TABLE_NAME").ToString().EndsWith("$") Select dr("TABLE_NAME")).ToList()
' cmbTableName.Enabled = cmbTableName.Items.Count > 0
' btnGo.Enabled = cmbTableName.Items.Count > 0
' btnDrop.Enabled = cmbTableName.Items.Count > 0
End Sub
Sub RetrieveExcel()
'Create a connection to either 2007 and 2010 xls file
Dim fi As New FileInfo(txtFilePath.Text)
If fi.Extension.Equals(".xls") Then
MyConnection = New OleDb.OleDbConnection("provider=Microsoft.Jet.OLEDB.8.0; " & "data source=" & txtFilePath.Text & "; " & "Extended Properties=Excel 8.0;")
ElseIf fi.Extension.Equals(".xlsx") Then
MyConnection = New OleDb.OleDbConnection( _
"provider=Microsoft.Ace.OLEDB.12.0; " & _
"data source=" & txtFilePath.Text & "; " & "Extended Properties=Excel 12.0;")
ElseIf fi.Extension.Equals(".xlsm") Then
MyConnection = New OleDb.OleDbConnection( _
"provider=Microsoft.Ace.OLEDB.12.0; " & _
"data source=" & txtFilePath.Text & "; " & "Extended Properties=Excel 12.0;")
End If
'First worksheet'
MyCommand = New OleDbDataAdapter("select * from [1- COTS Worksheet$A4:I150]", MyConnection)
'1- COTS Worksheet.Column(1).Locked = True
DS = New System.Data.DataSet()
MyCommand.Fill(DS)
'---This will prevent the user from editing the size of the rows and columns of the datagrid---'
DataGridView1.AllowUserToResizeColumns = False
DataGridView1.AllowUserToResizeRows = False
DataGridView1.AllowUserToOrderColumns = False
DataGridView1.AllowUserToAddRows = False
DataGridView1.AllowUserToDeleteRows = False
DataGridView1.DataSource = DS.Tables(0).DefaultView
'---The following line makes the column read only---'
DataGridView1.Columns(5).ReadOnly = True
DataGridView1.Columns(6).ReadOnly = True
'''''''if the column is editible then the foreground = blue ''''''''
DataGridView1.Columns(0).DefaultCellStyle.ForeColor = Color.Blue
DataGridView1.Columns(1).DefaultCellStyle.ForeColor = Color.Blue
DataGridView1.Columns(2).DefaultCellStyle.ForeColor = Color.Blue
DataGridView1.Columns(3).DefaultCellStyle.ForeColor = Color.Blue
DataGridView1.Columns(4).DefaultCellStyle.ForeColor = Color.Blue
DataGridView1.Columns(7).DefaultCellStyle.ForeColor = Color.Blue
DataGridView1.Columns(8).DefaultCellStyle.ForeColor = Color.Blue
' ''''''This will get rid of the selection blue color for the cells''''''''''''''''''''
DataGridView1.DefaultCellStyle.SelectionBackColor = DataGridView1.DefaultCellStyle.BackColor
DataGridView1.DefaultCellStyle.SelectionForeColor = DataGridView1.DefaultCellStyle.ForeColor
'TABLE TO WRITE TO -
'FIELD TO WRITE TO -
End Sub
Private Sub btnRetrieve_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRetrieve.Click
Try
Cursor.Current = Cursors.WaitCursor
RetrieveExcel()
Finally
Cursor.Current = Cursors.Default
End Try
End Sub
Private Sub Form1_Activated(sender As Object, e As EventArgs) Handles Me.Activated
End Sub
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
' btnRetrieve.Enabled = True
MyWorkspace = DAODBEngine_definst.Workspaces(0)
End Sub
Private Sub txtFilePath_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtFilePath.TextChanged
btnRetrieve.Enabled = System.IO.File.Exists(txtFilePath.Text)
End Sub
Private Sub Form1_FormClosed(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles MyBase.FormClosed
If Me.excelObj IsNot Nothing Then
Me.excelObj.Dispose()
End If
closexlsfile()
End Sub
Private Sub DBFilePath_TextChanged(sender As Object, e As EventArgs) Handles DBFilePath.TextChanged
End Sub
Private Sub BtnBrowseDB_Click(sender As Object, e As EventArgs) Handles BtnBrowseDB.Click
opendbfile()
End Sub
Function opendbfile() As Boolean
Dim dlg As New OpenFileDialog()
dlg.Filter = "DB files|*.mdb|Access DB files|*.accdb|All Files|*.*"
If dlg.ShowDialog() = DialogResult.OK Then
DBFilePath.Text = dlg.FileName
'temporarily myfile will be set to c:/Exceltest/template.mdb
' myfile = "c:/Exceltest/template.mdb"
Try
If DBFilePath.Text <> "" Then
'On Error GoTo errorhandler
MYDBConnection = MyWorkspace.OpenConnection("provider=Microsoft.Ace.OLEDB.12.0; " & "data source=" & txtFilePath.Text)
MyDatabase = MyWorkspace.OpenDatabase(DBFilePath.Text)
sizetable = MyDatabase.OpenRecordset("size", DAO.RecordsetTypeEnum.dbOpenTable)
End If
Catch ex As Exception
MsgBox(ex.Message)
End Try
End If
End Function
Private Sub btnWrite_Click(sender As Object, e As EventArgs) Handles btnWrite.Click
'---This Try Finally block with set current cursor to waiting cursor while the program write to excel---'
Try
Cursor.Current = Cursors.WaitCursor
Write2Excel()
Finally
Cursor.Current = Cursors.Default
End Try
End Sub
Sub closexlsfile()
Try
''Do we need to save the file first?
objWorkBook.Save()
objWorkBook.Close()
objExcel.Quit()
'something weird happening on this line
MyConnection.Close()
MyConnection.Dispose()
objWorkBook = Nothing
objExcel = Nothing
Catch
End Try
'TBD the other objworksheets get closed here
End Sub
Private Sub closexls_Click(sender As Object, e As EventArgs) Handles closexls.Click
closexlsfile()
NAR(objWorkSheet1)
NAR(objWorkSheet2)
NAR(objworksheet3)
NAR(objworksheet10)
NAR(objworksheet11)
NAR(objworksheet12)
NAR(objworksheet13)
NAR(objworksheet23)
NAR(objworksheet24)
objWorkBook.Close(False)
NAR(objWorkBook)
NAR(MyConnection)
objExcel.Quit()
NAR(objExcel)
Debug.WriteLine("Sleeping...")
System.Threading.Thread.Sleep(5000)
Debug.WriteLine("End Excel")
End Sub
'---This is a method that I found of MSDN to quit an office application but it doesn't seem to work---'
Private Sub NAR(ByVal obj As Object)
Try
While (System.Runtime.InteropServices.Marshal.ReleaseComObject(obj) > 0)
End While
Catch
Finally
obj = Nothing
End Try
End Sub
End Class

Answer 1

You obviously have a lot of code and I can't go through all of that. However I dealt with this problem in the past. It is usually due to an unreleased object of some kind. For example lots of code samples from the intertubes suggests that you do things like
objWorkBook = objExcel.Workbooks.Open(txtFilePath.Text)
This is potentially dangerous, you should never have more than ONE . in a single right hand value. Instead go for something like
Workbooks wrkbks = objExcel.Workbooks
objWorkBook = wrkbks.Open(txtFilePath.Text)
Otherwise there will be memory allocated for the WorkBooks that isn't explicitly released. This is really a pain to go through all your code base once you've discovered this, but it solved the problem for me.

Answer 2

Your NAR sub should have it handled, but I far prefer Marshal.FinalReleaseComObject method - no loop required. You need to make sure all instances have been addressed - like in the closexlsfile() method you do not call NAR for these Com objects. I suggest some code cleanup.