C#

using Microsoft.Office.Interop.Excel;

public ExcelFile(string excelFile)
{
    application = new Application();

    if (!File.Exists(excelFile))
    {
        this.workbook = application.Workbooks.Add(XlWBATemplate.xlWBATWorksheet);
        this.workbook.SaveAs(excelFile, XlFileFormat.xlAddIn8, "", "", false, false, XlSaveAsAccessMode.xlNoChange, XlSaveConflictResolution.xlLocalSessionChanges, false, Type.Missing, Type.Missing, true);
        this.workbook.Close(true, Type.Missing, Type.Missing);
     }
     this.workbook = application.Workbooks.Open(excelFile, 0, false, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
}

string[] Field = new string[9];//defining array
       private string SaveDataBeforDel(string Fr_Name, string Sr_Name, string St_Id, double Lb_Mark, double Ass1, double Ass2, double Fnl, double TotalMark, string Grade)
       {
           Field[0] = Fr_Name;
           Field[1] = Sr_Name;
           Field[2] = St_Id;
           Field[3] = Convert.ToString(Lb_Mark);
           Field[4] = Convert.ToString(Ass1);
           Field[5] = Convert.ToString(Ass2);
           Field[6] = Convert.ToString(Fnl);
           Field[7] = Convert.ToString(TotalMark);
           Field[8] = Grade;

           CleabTxtBox();
           return string.Empty;
       }

private void LstBox_SelectedIndexChanged_1(object sender, EventArgs e)
       {
           if (LstBox.SelectedIndex != -1)
           {
               ITECH3219Student s = (ITECH3219Student)LstBox.SelectedItem;
               Assigningdata_Totextbox(s.Fr_name.ToString(), s.Sr_Name.ToString(), s.St_Id.ToString(), s.Lb_Mark, s.Ass1, s.Ass2, s.Fnl, s.TotalMarkCalculation(),s.Grade.ToString());
           }

       }

private void Btn_Del_Click(object sender, EventArgs e)
       {
           Btn_Del.Enabled = false;
           Btn_undo.Enabled = true;

           SaveDataBeforDel(Txt_name.Text, Txt_surname.Text, Txt_Id.Text,Convert.ToDouble(Txt_lbmark.Text), Convert.ToDouble(Txt_ass1.Text), Convert.ToDouble(Txt_ass2.Text), Convert.ToDouble(Txt_final.Text),Convert.ToDouble(Txt_total.Text), Txt_grade.Text);
           LstBox.Items.RemoveAt(LstBox.SelectedIndex);
       }

private void Btn_undo_Click(object sender, EventArgs e)
        {
            Btn_Del.Enabled = true;
            Btn_undo.Enabled = false;

            Student_Manipulation s = new Student_Manipulation();
            LstBox.Items.Add(s.AddStudent_Tolist(Field[0], Field[1], Field[2]));

            Txt_lbmark.Text = Field[3];
            Txt_ass1.Text = Field[4];
            Txt_ass2.Text = Field[5];
            Txt_final.Text = Field[6];
            Txt_total.Text = Field[7];
            Txt_grade.Text = Field[8];

            ITECH3219Student s1 = (ITECH3219Student)LstBox.SelectedItem;
            Assigningdata_Totextbox(Field[0], Field[1], Field[2], Convert.ToDouble(Field[3]), Convert.ToDouble(Field[4]), Convert.ToDouble(Field[5]), Convert.ToDouble(Field[6]), Convert.ToDouble(Field[7]), Field[8]);