c# how to read write excel spreedsheet

用.net读写excel文件有很多种方法，这里介绍一种比较简单的:

使用Microsoft.Office.Interop.Excel

下面是一个我项目中的一个读取函数的删减版本，要用上using Excel = Microsoft.Office.Interop.Excel;

除了读取一个Range里的东西，下面的函数演示了怎么枚举所有的行列，这样就可以不用事先知道Range了。

private void LoadExcelFile(string annotationFile)
        {
            Excel.Workbooks objBooks;
            Excel.Sheets objSheets;
            Excel._Worksheet objSheet;
            Excel.Range range;
            
            try
            {
                // Instantiate Excel and start a new workbook.
                objApp = new Excel.Application();
                objBooks = objApp.Workbooks;
                objBook = objBooks.Open(annotationFile, Missing.Value, true, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
                objSheets = objBook.Worksheets;
                objSheet = (Excel._Worksheet)objSheets.get_Item(1);


                //Get a range of data.
                range = objSheet.get_Range("A1", Missing.Value);
                range = range.get_Resize(1, 1);
                double videoTimeOffset = (double)range.get_Value(Missing.Value);

                //Another way of getting data
                string output = "";
                int rowIndex = 3;
                //object colIndex2 = 11;
                while (((Excel.Range)objSheet.Cells[rowIndex, 1]).Value2 != null)
                {
                    string tmp = "";
                    int lapID;
                    SwimLap.StrokeTypeEnum strokeType;
                    string lapType;  //Warm Up/Down Main
                    
                    tmp = (((Excel.Range)objSheet.Cells[rowIndex, 1]).Value2 == null) ? "-" : ((Excel.Range)objSheet.Cells[rowIndex, 1]).Value2.ToString();
                    if (tmp.Equals(" ") || tmp.Equals("-"))
                        lapID = 0;
                    else
                        lapID = Convert.ToInt32(tmp);

                    tmp = (((Excel.Range)objSheet.Cells[rowIndex, 2]).Value2 == null) ? "-" : ((Excel.Range)objSheet.Cells[rowIndex, 2]).Value2.ToString();
                    strokeType = SwimLap.GetStrokeTypeEnum(tmp);

                    lapType = (((Excel.Range)objSheet.Cells[rowIndex, 3]).Value2 == null) ? "-" : ((Excel.Range)objSheet.Cells[rowIndex, 3]).Value2.ToString();

                    
                    SwimLap sl = new SwimLap(videoTimeOffset,lapID,strokeType,lapType,lapTime,lapVideoStartTime,lapVideoEndTime,strokeCount,confidence,isTurn,isVideoFullLap,startType,strokeRate);

                    ss.AddLap(sl);

                    rowIndex++;
                    
                }

                objBooks.Close();
                objApp.Quit();

            }
            catch (Exception theException)
            {
                String errorMessage;
                errorMessage = "Error: ";
                errorMessage = String.Concat(errorMessage, theException.Message);
                errorMessage = String.Concat(errorMessage, " Line: ");
                errorMessage = String.Concat(errorMessage, theException.Source);
                MessageBox.Show(errorMessage, "Error");
            }
        }