使用剪切板在DataGridView与Excel间复制粘贴数据

#region//利用剪切板进行数据的复制和粘贴
        private void ExportDataByUsingClipboardCopyAndPaste(DataGridView dg,DataGridView dgUnit)
        {
            dg.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            for (int i = 0; i < dg.Rows.Count; i++)
            {
                dg.Rows[i].Selected = true;
            }
            dg.ClipboardCopyMode = DataGridViewClipboardCopyMode.EnableAlwaysIncludeHeaderText;
            Clipboard.SetDataObject(dg.GetClipboardContent());
            Excel.Application excel = new Excel.Application();
            excel.Application.Workbooks.Add(true);

            excel.Cells.PasteSpecial(Excel.XlPasteType.xlPasteAll, Excel.XlPasteSpecialOperation.xlPasteSpecialOperationAdd, Type.Missing, Type.Missing);
            #region//粘贴完成以后，把表头部分换成带单位的
            if (dgUnit != null)
            {
                for (int i = 0; i < dg.ColumnCount; i++)
                {
                    string headertxt = dg.Columns[i].HeaderText;
                    #region//对unit单位表是否为空的判断
                    if (dgUnit != null)//单位表不是空的情况
                    {
                        for (int j = 0; j < dgUnit.Rows.Count; j++)
                        {
                            string headerUnit = dgUnit.Rows[j].Cells[1].Value.ToString();
                            if (headerUnit == headertxt)
                            {
                                string unitstring = dgUnit.Rows[i].Cells[2].Value.ToString();
                                if (unitstring.ToLower() != "string" && !headerUnit.Contains(unitstring)) { headertxt = headertxt + "(" + unitstring + ")"; }