**Reading the Excel File:**
string filePath = @"d:\MyExcel.xlsx";
Excel.Application xlApp = new Excel.Application();
Excel.Workbook xlWorkBook = xlApp.Workbooks.Open(filePath);
Excel.Worksheet xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
Excel.Range xlRange = xlWorkSheet.UsedRange;
int totalRows = xlRange.Rows.Count;
int totalColumns = xlRange.Columns.Count;
string firstValue, secondValue;
for (int rowCount = 1; rowCount <= totalRows; rowCount++)
{
firstValue = Convert.ToString((xlRange.Cells[rowCount, 1] as Excel.Range).Text);
secondValue = Convert.ToString((xlRange.Cells[rowCount, 2] as Excel.Range).Text);
Console.WriteLine(firstValue + "\t" + secondValue);
}
xlWorkBook.Close();
xlApp.Quit();
**Writting the Excel File:**
Excel.Application xlApp = new Excel.Application();
object misValue = System.Reflection.Missing.Value;
Excel.Workbook xlWorkBook = xlApp.Workbooks.Add(misValue);
Excel.Worksheet xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
xlWorkSheet.Cells[1, 1] = "ID";
xlWorkSheet.Cells[1, 2] = "Name";
xlWorkSheet.Cells[2, 1] = "100";
xlWorkSheet.Cells[2, 2] = "John";
xlWorkSheet.Cells[3, 1] = "101";
xlWorkSheet.Cells[3, 2] = "Herry";
xlWorkBook.SaveAs(filePath, Excel.XlFileFormat.xlOpenXMLWorkbook, misValue, misValue, misValue, misValue,
Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
xlWorkBook.Close();
xlApp.Quit();