VB.netでExcelのプロセスが終了しない

Question

前提

バイトをしていてもっと効率化できると思い、独学でVB.netを初めてのプログラミング言語として学び始めたものです。
Excelに画像を貼り付けるという作業があり、それを自動化するソフトを開発しましたがExcelのプロセスが終了しないです。

実現したいこと

処理完了と同時にプロセスも同時に終了できるようにしたいです。

発生している問題・エラーメッセージ

処理をするごとにExcelを起動してしまうので、たくさん処理をした際に多重起動で重くなってしまう

該当のソースコード

Private Sub testing_button2_Click(sender As Object, e As EventArgs) Handles testing_button2.Click

        Dim strCurrentDir As String = System.IO.Directory.GetCurrentDirectory()
        Dim template As String = strCurrentDir + "\" + "template.xls"
        Dim xlApp As New Excel.Application

        Dim fbd As New FolderBrowserDialog

        'Adding header description
        fbd.Description = "エクセルファイルの保存先を指定してください。"
        'Allow users to create new folders
        'True as default
        fbd.ShowNewFolderButton = True

        ProgressBar1.Minimum = 0
        ProgressBar1.Maximum = folder_lists.CheckedItems.Count
        ProgressBar1.Value = 0

        If fbd.ShowDialog(Me) = DialogResult.OK Then  'show save distination setting dialog
            For Each item_fld As ListViewItem In folder_lists.CheckedItems
                Dim imagePath As String = item_fld.SubItems(1).Text
                Dim extensions As String() = {"*.jpg", "*.png", "*.bmp"}
                Dim files As New List(Of String)
                ProgressBar1.Value = ProgressBar1.Value + 1

                For Each extension As String In extensions  'counting multiple extension files
                    files.AddRange(Directory.GetFiles(imagePath, extension))
                Next

                Dim filesCount As Integer = files.Count 'amount of image files


                Dim xlWorkbook As Excel.Workbook = xlApp.Workbooks.Open(template)
                Dim xlWorksheet As Excel.Worksheet = xlWorkbook.Sheets(1)

                Dim rng As Long = 1

                For Each file As String In files    'insert pictures to the excel book
                    Debug.WriteLine(file)
                    xlWorksheet.Shapes.AddPicture(file, MsoTriState.msoTrue, MsoTriState.msoTrue, xlWorksheet.Range("B" & rng).Left, xlWorksheet.Range("B" & rng).Top, 355, 252)
                    rng = rng + 12
                Next

                For Each shape As Excel.Shape In xlWorksheet.Shapes 'move down all images because of print bug
                    shape.Top = shape.Top + 3
                Next
                xlWorkbook.SaveAs(fbd.SelectedPath & "\" & item_fld.Text & ".xls")
                xlWorkbook.Close()

                xlApp.Quit()
            Next

        End If
        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp)
        ProgressBar1.Value = 0

    End Sub

試したこと

オブジェクトの開放

補足情報（FW/ツールのバージョンなど）

Comments

[bebebe_]

うろ覚えですが
xlWorkbook
xlWorksheet
shapeも解放が必要かと思います。
それとたしか「Dim xlWorkbook As Excel.Workbook = xlApp.Workbooks.Open(template)」のように.が2個あってもだめだったと思うので
Dim xlWorkbooks As Excel.Workbooks = xlApp.Workbooks
Dim xlbook As Excel.Workbook = Workbooks.Open(template)
のようにしてxlbookも解放しましょう。

Excelの扱いは大変なのでClosedXML等のライブラリを使ったほうが楽になるかもしれません。

[KOZ6.0]

NerOffice を使うといいんじゃないでしょうか。
https://netoffice.io/
https://blog.jhashimoto.net/entry/20120826/1351042349

Answer 1

動作確認はしていませんが、Excel操作関係をループ外に出して、最後に順に解放とかどうでしょうか。

Private Sub testing_button2_Click(sender As Object, e As EventArgs) Handles testing_button2.Click

        Dim strCurrentDir As String = System.IO.Directory.GetCurrentDirectory()
        Dim template As String = strCurrentDir + "\" + "template.xls"
        Dim xlApp As New Excel.Application
        Dim xlWorkbook As Excel.Workbook      ' ← ここで宣言
        Dim xlWorksheet As Excel.Worksheet    ' ← ここで宣言

        Dim fbd As New FolderBrowserDialog

        'Adding header description
        fbd.Description = "エクセルファイルの保存先を指定してください。"
        'Allow users to create new folders
        'True as default
        fbd.ShowNewFolderButton = True

        ProgressBar1.Minimum = 0
        ProgressBar1.Maximum = folder_lists.CheckedItems.Count
        ProgressBar1.Value = 0

        If fbd.ShowDialog(Me) = DialogResult.OK Then  'show save distination setting dialog
            For Each item_fld As ListViewItem In folder_lists.CheckedItems
                Dim imagePath As String = item_fld.SubItems(1).Text
                Dim extensions As String() = {"*.jpg", "*.png", "*.bmp"}
                Dim files As New List(Of String)
                ProgressBar1.Value = ProgressBar1.Value + 1

                For Each extension As String In extensions  'counting multiple extension files
                    files.AddRange(Directory.GetFiles(imagePath, extension))
                Next

                Dim filesCount As Integer = files.Count 'amount of image files


                xlWorkbookk = xlApp.Workbooks.Open(template)   ' ここはdim宣言せず、代入のみ
                xlWorksheet = xlWorkbook.Sheets(1)             ' ここはdim宣言せず、代入のみ

                Dim rng As Long = 1

                For Each file As String In files    'insert pictures to the excel book
                    Debug.WriteLine(file)
                    xlWorksheet.Shapes.AddPicture(file, MsoTriState.msoTrue, MsoTriState.msoTrue, xlWorksheet.Range("B" & rng).Left, xlWorksheet.Range("B" & rng).Top, 355, 252)
                    rng = rng + 12
                Next

                For Each shape As Excel.Shape In xlWorksheet.Shapes 'move down all images because of print bug
                    shape.Top = shape.Top + 3
                Next
                xlWorkbook.SaveAs(fbd.SelectedPath & "\" & item_fld.Text & ".xls")
                xlWorkbook.Close()

            Next
            xlApp.Quit()   ' 位置変更

        End If
        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorksheet)  ' シート
        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkbook)   ' ブック
        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp)        ' アプリの順で開放
        ProgressBar1.Value = 0

    End Sub