npoi 合併單元值處理

獲取sheet中存在合併單元格總數，迴圈綁定值 

            // 得到一個sheet中有多少個合併單元格
            int sheetMergeCount = sheet.NumMergedRegions;
            for (var i = 0; i < sheetMergeCount; i++)
            {
                // 獲取合併後的單元格
                var range = sheet.GetMergedRegion(i);
                sheet.IsMergedRegion(range);
                var cellValue = sheet.GetRow(range.FirstRow).GetValue(range.FirstColumn).FormatUtf8String();
                for (var mRowIndex = range.FirstRow; mRowIndex <= range.LastRow; mRowIndex++)
                {
                    for (var mColumnIndex = range.FirstColumn; mColumnIndex <= range.LastColumn; mColumnIndex++)
                    {
                        table.Rows[mRowIndex][mColumnIndex] = cellValue;
                    }
                }
            }