c#操作Excel文件(office 11.0 object library)

using Microsoft.Office.Interop.Excel;
namespace FileHandler
{
    public class ExcelFile
{
        public ExcelFile(string fileName)
{
            if(!Initial())
                return;

            excelFileName = fileName;
 
            //加入新的WorkBook
            //获取WorkBooks集合

            workbooks = excelApp.Workbooks;
            if(!System.IO.File.Exists(fileName)) 

                workbook = workbooks.Add(XlWBATemplate.xlWBATWorksheet);
            }
            else
                //*修改原有文件
                workbook = workbooks.Add(excelFileName);

            //获取WorkSheets集合
            sheets = workbook.Worksheets;
            worksheet = (Worksheet) sheets.get_Item(1); 
            if (worksheet == null) 
{ 
                MessageBox.Show("worksheet is null!","Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            } 

        }

        public void Dispose()
{
            if(isInitialed && excelApp != null)
            excelApp.Quit();
        }

        public bool Initial()
{
            if(!isInitialed)
{
                excelApp = new Microsoft.Office.Interop.Excel.Application();
                if (excelApp == null) 
{ 
                    MessageBox.Show("Excel couldn't be started!","Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return false;
                }
                excelApp.DisplayAlerts = false;
                isInitialed = true;
            }
            return true;
        }
        private static Microsoft.Office.Interop.Excel.Application excelApp;
        private Microsoft.Office.Interop.Excel.Workbooks workbooks;
        private Microsoft.Office.Interop.Excel.Workbook workbook;
        private Sheets sheets;
        private Worksheet worksheet;
        private string excelFileName;
        private static bool isInitialed = false;

        public void Write(int row, int column, object val)
{
            worksheet.Cells[row, column] = val;
        }
        public object Read(int row, int column)
{
            return worksheet.Cells[row, column];
        }

        public void Save()
{
            if(!workbook.Saved)
{
                workbook.Close(true,excelFileName,true);
            }
        }
    }
}