/// <summary>
        /// 電子表格匯出
        /// </summary>
        /// <exception cref="ArgumentNullException">未建立任何工作表。</exception>
        public byte[] Export()
        {
            Validate();
            SheeterContext[] contexts = new SheeterContext[sheeters.Count];
            for (int i = 0; i < sheeters.Count; i++)
            {
                Sheeter sheeter = sheeters[i];

                contexts[i] = new SheeterContext(
                    sheeter.SheetName,
                    sheeter.Templates.Select(x => x.GetContext()),
                    sheeter.ColumnWidths.ToDictionary(x => x.Key, x => x.Value)
                    );
            }
            return(ExecuteExport(contexts));
        }
        public Sheeter CreateSheeter(string sheetName = "")
        {
            if (string.IsNullOrWhiteSpace(sheetName))
            {
                sheetName = GetDefaultSheetName();
            }
            else if (IsSheetNameExists(sheetName))
            {
                sheetName = FixSheetName(sheetName);
            }

            Sheeter sheeter = new Sheeter(sheetName);

            sheeters.Add(sheeter);

            return(sheeter);
        }