Office Open XML学习(1)-创建excel文档，并向单元格中插入字符串

做企业级应用，跟office打交道是少不了的。这里的Office不仅仅局限于微软的Office，还有第三方的Open Office之类。.Net传统的Office操作方法（比如OleDB,OWC之类），有几大缺点:
一是不通用(仅能处理微软的Office，不能与其它非Windows平台交换数据)，
二是性能差（导出一个Excel，如果记录数上万条，速度很慢），
三是服务器通常要安装Office Web Components(即OWC组件)。

自从Open XML出现后，这种情况在很大程度上得到了改观，Open XML已经逐渐成为一种办公文档的通用国际标准了(该标准基于XML格式)，详情见百度百科 http://baike.baidu.com/view/1201978.htm

要在C#中使用Open XML，需先下载Open XML SDK (目前最高版本为2.0)，下载地址为：http://www.microsoft.com/downloads/en/details.aspx?FamilyID=c6e744e5-36e9-45f5-8d8c-331df206e0d0

安装完以后，就能直接使用了，下面的代码演示了，如何创建一个Excel文档，并创建一个工作表"博客园"，最后在该工作表的单元格A1中插入字符串

using System;
using System.IO;
using System.Linq;
using System.Windows.Forms;
using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;

namespace ExcelSample
{
    class Program
    {
        static void Main(string[] args)
        {
            string excelFilePath = Path.Combine(Path.GetDirectoryName(Application.ExecutablePath), "Sample.xlsx");

            using (SpreadsheetDocument excelDocument = CreateSpreadsheetDocument(excelFilePath))
            {
                //添加工作表(Sheet)-"博客园"
                WorksheetPart worksheetPart = InsertWorksheet(excelDocument.WorkbookPart,"博客园");

                //工作表插入单元格A1
                Cell cell = InsertCellInWorksheet("A", 1, worksheetPart);

                //创建多个工作表可共用的字符串容器
                SharedStringTablePart shareStringPart = CreateSharedStringTablePart(excelDocument.WorkbookPart);                

                //在共用字符串容器里插入一个字符串
                int strIndex = InsertSharedStringItem("菩提树下的杨过 http://www.cnblogs.com/yjmyzz", shareStringPart);

                //设置单元格的"值"
                cell.DataType = new EnumValue<CellValues>(CellValues.SharedString);
                cell.CellValue = new CellValue(strIndex.ToString());//注：这里要设置为目标字符串在SharedStringTablePart中的索引

                worksheetPart.Worksheet.Save();
            }

            Console.WriteLine("{0} 已经成功生成!", excelFilePath);

            Console.Read();
        }

        /// <summary>
        /// 创建一个SpreadsheetDocument对象
        /// </summary>
        /// <param name="excelFileName"></param>
        /// <returns></returns>
        static SpreadsheetDocument CreateSpreadsheetDocument(string excelFileName)
        {
            SpreadsheetDocument excel = SpreadsheetDocument.Create(excelFileName, SpreadsheetDocumentType.Workbook, true);
            WorkbookPart workbookpart = excel.AddWorkbookPart();
            workbookpart.Workbook = new Workbook();
            return excel;
        }

        /// <summary>
        /// 插入worksheet
        /// </summary>
        /// <param name="workbookPart"></param>
        /// <returns></returns>
        private static WorksheetPart InsertWorksheet(WorkbookPart workbookPart, string sheetName = null)
        {
            //创建一个新的WorkssheetPart（后面将用它来容纳具体的Sheet）
            WorksheetPart newWorksheetPart = workbookPart.AddNewPart<WorksheetPart>();
            newWorksheetPart.Worksheet = new Worksheet(new SheetData());
            newWorksheetPart.Worksheet.Save();

            //取得Sheet集合
            Sheets sheets = workbookPart.Workbook.GetFirstChild<Sheets>();
            if (sheets == null)
            {
                sheets = workbookPart.Workbook.AppendChild<Sheets>(new Sheets());
            }

            string relationshipId = workbookPart.GetIdOfPart(newWorksheetPart);

            //得到Sheet的唯一序号
            uint sheetId = 1;
            if (sheets.Elements<Sheet>().Count() > 0)
            {
                sheetId = sheets.Elements<Sheet>().Select(s => s.SheetId.Value).Max() + 1;
            }

            string sheetTempName = "Sheet" + sheetId;

            if (sheetName != null)
            {
                bool hasSameName = false;
                //检测是否有重名
                foreach (var item in sheets.Elements<Sheet>())
                {
                    if (item.Name == sheetName)
                    {
                        hasSameName = true;
                        break;
                    }
                }
                if (!hasSameName)
                {
                    sheetTempName = sheetName;
                }
            }

            //创建Sheet实例并将它与sheets关联
            Sheet sheet = new Sheet() { Id = relationshipId, SheetId = sheetId, Name = sheetTempName };
            sheets.Append(sheet);
            workbookPart.Workbook.Save();

            return newWorksheetPart;
        }

        /// <summary>
        /// 创建一个SharedStringTablePart(相当于各Sheet共用的存放字符串的容器)
        /// </summary>
        /// <param name="workbookPart"></param>
        /// <returns></returns>
        private static SharedStringTablePart CreateSharedStringTablePart(WorkbookPart workbookPart)
        {
            SharedStringTablePart shareStringPart = null;
            if (workbookPart.GetPartsOfType<SharedStringTablePart>().Count() > 0)
            {
                shareStringPart = workbookPart.GetPartsOfType<SharedStringTablePart>().First();
            }
            else
            {
                shareStringPart = workbookPart.AddNewPart<SharedStringTablePart>();
            }
            return shareStringPart;
        }

        /// <summary>
        /// 向工作表插入一个单元格
        /// </summary>
        /// <param name="columnName">列名称</param>
        /// <param name="rowIndex">行索引</param>
        /// <param name="worksheetPart"></param>
        /// <returns></returns>
        private static Cell InsertCellInWorksheet(string columnName, uint rowIndex, WorksheetPart worksheetPart)
        {
            Worksheet worksheet = worksheetPart.Worksheet;
            SheetData sheetData = worksheet.GetFirstChild<SheetData>();
            string cellReference = columnName + rowIndex;//列的引用字符串，类似:"A3"或"B5"

            //如果指定的行存在，则直接返回该行，否则插入新行
            Row row;
            if (sheetData.Elements<Row>().Where(r => r.RowIndex == rowIndex).Count() != 0)
            {
                row = sheetData.Elements<Row>().Where(r => r.RowIndex == rowIndex).First();
            }
            else
            {
                row = new Row() { RowIndex = rowIndex };
                sheetData.Append(row);
            }

            //如果该行没有指定ColumnName的列，则插入新列，否则直接返回该列
            if (row.Elements<Cell>().Where(c => c.CellReference.Value == columnName + rowIndex).Count() > 0)
            {
                return row.Elements<Cell>().Where(c => c.CellReference.Value == cellReference).First();
            }
            else
            {
                //列必须按(字母)顺序插入，因此要先根据"列引用字符串"查找插入的位置
                Cell refCell = null;
                foreach (Cell cell in row.Elements<Cell>())
                {
                    if (string.Compare(cell.CellReference.Value, cellReference, true) > 0)
                    {
                        refCell = cell;
                        break;
                    }
                }

                Cell newCell = new Cell() { CellReference = cellReference };
                row.InsertBefore(newCell, refCell);

                worksheet.Save();
                return newCell;
            }
        }

        /// 向SharedStringTablePart添加字符串
        /// </summary>
        /// <param name="text">字符串内容</param>
        /// <param name="shareStringPart">sharedStringTablePart内容</param>
        /// <returns>如果要添加的字符串已经存在，则直接返回该字符串的索引</returns>
        private static int InsertSharedStringItem(string text, SharedStringTablePart shareStringPart)
        {
            //检测SharedStringTable是否存在，如果不存在，则创建一个
            if (shareStringPart.SharedStringTable == null)
            {
                shareStringPart.SharedStringTable = new SharedStringTable();
            }

            int i = 0;

            //遍历SharedStringTable中所有的Elements，查看目标字符串是否存在
            foreach (SharedStringItem item in shareStringPart.SharedStringTable.Elements<SharedStringItem>())
            {
                if (item.InnerText == text)
                {
                    return i;
                }
                i++;
            }

            //如果目标字符串不存在，则创建一个，同时把SharedStringTable的最后一个Elements的"索引+1"返回
            shareStringPart.SharedStringTable.AppendChild(new SharedStringItem(new DocumentFormat.OpenXml.Spreadsheet.Text(text)));
            shareStringPart.SharedStringTable.Save();

            return i;
        }
    }
}

Sample.xlsx的打开截图: