Writing Data to an Existing Excel File in C#

Question

I want to write data to an existing Excel file, whilst preserving the original data.

The file has sheet1; I want to write on sheet2, then save. The problem is that e

Answer 1

This is my way to add data to existing excel file: (Its very simple and efficient)

1 - Add Microsoft.Office.Interop.Excel component as a reference to your application You can find it in .Net FrameWork in Extensions section

2- then add:

using Excel = Microsoft.Office.Interop.Excel;
using System.Reflection;

3- Now I have a simple class with 3 methods (openExcel, addDataToExcel, closeExcel)

public class ExcelFile
{

    private string excelFilePath = string.Empty;
    private int rowNumber = 1; // define first row number to enter data in excel

    Excel.Application myExcelApplication;
    Excel.Workbook myExcelWorkbook;
    Excel.Worksheet myExcelWorkSheet;

    public string ExcelFilePath
    {
        get { return excelFilePath; }
        set { excelFilePath = value; }
    }

    public int Rownumber
    {
        get { return rowNumber; }
        set { rowNumber = value; }
    }

    public void openExcel()
    {
        myExcelApplication = null;

        myExcelApplication = new Excel.Application(); // create Excell App
        myExcelApplication.DisplayAlerts = false; // turn off alerts


        myExcelWorkbook = (Excel.Workbook)(myExcelApplication.Workbooks._Open(excelFilePath, System.Reflection.Missing.Value,
           System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value,
           System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value,
           System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value,
           System.Reflection.Missing.Value, System.Reflection.Missing.Value)); // open the existing excel file

        int numberOfWorkbooks = myExcelApplication.Workbooks.Count; // get number of workbooks (optional)

        myExcelWorkSheet = (Excel.Worksheet)myExcelWorkbook.Worksheets[1]; // define in which worksheet, do you want to add data
        myExcelWorkSheet.Name = "WorkSheet 1"; // define a name for the worksheet (optinal)

        int numberOfSheets = myExcelWorkbook.Worksheets.Count; // get number of worksheets (optional)
    }

    public void addDataToExcel(string firstname, string lastname, string language, string email, string company)
    {

        myExcelWorkSheet.Cells[rowNumber, "H"] = firstname;
        myExcelWorkSheet.Cells[rowNumber, "J"] = lastname;
        myExcelWorkSheet.Cells[rowNumber, "Q"] = language;
        myExcelWorkSheet.Cells[rowNumber, "BH"] = email;
        myExcelWorkSheet.Cells[rowNumber, "CH"] = company;
        rowNumber++;  // if you put this method inside a loop, you should increase rownumber by one or wat ever is your logic

    }

    public void closeExcel()
    {
        try
        {
            myExcelWorkbook.SaveAs(excelFilePath, System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value,
                                           System.Reflection.Missing.Value, System.Reflection.Missing.Value, Excel.XlSaveAsAccessMode.xlNoChange,
                                           System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value,
                                           System.Reflection.Missing.Value, System.Reflection.Missing.Value); // Save data in excel


            myExcelWorkbook.Close(true, excelFilePath, System.Reflection.Missing.Value); // close the worksheet


        }
        finally
        {
            if (myExcelApplication != null)
            {
                myExcelApplication.Quit(); // close the excel application
            }
        }

    }
}