How to count exact no of rows from excal sheet and save it in datatable and also show it in gridview in c#

public static DataSet ImportExceltoDataset(string YourFilePath)
        {

            Microsoft.Office.Interop.Excel.Application oXL;
            Workbook oWB;
            Worksheet oSheet;

            Range oRng;
            //  creat a Application object
            oXL = new Microsoft.Office.Interop.Excel.Application();
            try
            {
                //   get   WorkBook  object
                oWB = oXL.Workbooks.Open(fileName, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                        Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                        Missing.Value, Missing.Value);

                //   get   WorkSheet object 
                int M = oXL.Worksheets.Count;

                for (int sheetnum = 1; sheetnum <= M; sheetnum++)
                {
                    oSheet = (Microsoft.Office.Interop.Excel.Worksheet)oWB.Sheets[sheetnum];

                    for (int j = oSheet.UsedRange.Cells.Columns.Count + 10; j > 0; j--)
                    {
                        if (j > oSheet.UsedRange.Cells.Columns.Count)
                        {
                            if (string.IsNullOrEmpty(((Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j]).Text.ToString()))
                            {
                                ((Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j]).EntireColumn.Delete(null);
                            }
                        }
                        else
                        {
                            if (string.IsNullOrEmpty(((Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j]).Text.ToString()))
                            {
                                int IsDeleteCunt = 1;
                                for (int i = 1; i < oSheet.UsedRange.Cells.Rows.Count; i++)
                                {
                                    if (string.IsNullOrEmpty(((Microsoft.Office.Interop.Excel.Range)oSheet.Cells[i, j]).Text.ToString()))
                                    {
                                        IsDeleteCunt++;
                                    }
                                    else
                                    {
                                        break;
                                    }
                                }
                                if (IsDeleteCunt == oSheet.UsedRange.Cells.Rows.Count)// Here you can get the used rows.
                                {
                                    ((Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j]).EntireColumn.Delete(null);
                                }
                            }
                        }
                    }
                }

                DataSet ds = new DataSet();
                string WrkshtName = "";
                for (int N = 1; N <= M; N++)
                {
                    oSheet = (Microsoft.Office.Interop.Excel.Worksheet)oWB.Sheets[N];
                    WrkshtName = oSheet.Name;
                    System.Data.DataTable dt = new System.Data.DataTable(WrkshtName);
                    ds.Tables.Add(dt);
                    DataRow dr;

                    StringBuilder sb = new StringBuilder();

                    int jValue = oSheet.UsedRange.Cells.Columns.Count;
                    int iValue = oSheet.UsedRange.Cells.Rows.Count;
                    int EmptyColumnCount = 1;
                    for (int j = 1; j <= jValue; j++)
                    {
                        oRng = (Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j];

                        string strValue = oRng.Text.ToString();
                        if (strValue.Trim() == "")
                        {
                            EmptyColumnCount++;
                        }

                        dt.Columns.Add(strValue, System.Type.GetType("System.String"));
                    }
                    if (EmptyColumnCount >= jValue)
                    {
                        ds.Tables.Remove(WrkshtName);
                    }
                    else
                    {
                        for (int i = 2; i <= iValue; i++)
                        {
                            dr = ds.Tables[WrkshtName].NewRow();
                            int k = 0;
                            EmptyColumnCount = 1;
                            for (int j = 1; j <= jValue; j++)
                            {
                                oRng = (Microsoft.Office.Interop.Excel.Range)oSheet.Cells[i, j];
                                ((Range)oSheet.Cells[1, j]).EntireColumn.AutoFit();

                                string strValue = oRng.Text.ToString();
                                if (strValue.Trim() == "")
                                {
                                    EmptyColumnCount++;
                                }
                                dr[k] = strValue;
                                k++;
                            }
                            if (EmptyColumnCount < jValue)
                            {
                                ds.Tables[WrkshtName].Rows.Add(dr);
                            }
                        }
                    }
                }
                return ds;
            }
            catch (Exception ex)
            {
                return null;
            }   
        }