ConvineBooks

ConvineBooks.cs

private void ConvineBooks(object sender, RibbonControlEventArgs e)
{
    // アプリケーション
    Excel.Application thisApp = Globals.ThisAddIn.Application;
    // 現在のブック
    Excel.Workbook thisBook = thisApp.ActiveWorkbook;

    using (FolderBrowserDialog fbd = new FolderBrowserDialog())
    {
        if (fbd.ShowDialog() == DialogResult.OK)
        {
            string[] files = Directory.GetFiles(fbd.SelectedPath).Where(x => Path.GetExtension(x) == ".xlsx").ToArray();

            foreach (string file in files)
            {
                try
                {
                    Excel.Workbook book;
                    // 現在のアプリケーションで開かないと、Copyで死ぬ。
                    book = (Excel.Workbook)(thisApp.Workbooks.Open(file));

                    try
                    {
                        foreach (Excel.Worksheet sheet in book.Sheets)
                        {
                            // シート[1]の後ろにコピーする
                            sheet.Copy(Type.Missing, thisBook.Worksheets[1]);
                        }
                    }
                    finally
                    {
                        book.Close(false, Type.Missing, Type.Missing);
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }
    }
}