for (int i = 0; i < table.Columns.Count; i++)
            {
                string ColumnName = table.Columns[i].Caption;
                for (int row = 0; row < table.Rows.Count; row++)
                {

                    if ("ABCD".IndexOf(ColumnName) > -1)
                    {
                        if (!codeList.Contains(table.Rows[row][1].ToString()))
                            codeList.Add(table.Rows[row][1].ToString());
                        //循环判断改行的后面行是否有相同的，，有则一行行合并
                        for (int r = row; r < table.Rows.Count; r++)
                        {
                            if (r != table.Rows.Count - 1 && table.Rows[r][i].ToString() == table.Rows[r + 1][i].ToString())
                            {                               
                                rang = (_Excel.Range)sheet.get_Range(table.Columns[i].Caption + (r + 2), table.Columns[i].Caption + (r + 2 + 1));
                                rang.MergeCells = true;
                            }
                        }
                    }
                    sheet.Cells[row + 2, i + 1] = table.Rows[row][i].ToString();
                }
            }