Excel to Gridview

In .aspx file:  

<form id="form1" runat="server">

    <div>

        <asp:Label ID="Label1" runat="server" Text=""></asp:Label>

    <br />

    <table>

    <tr><td><asp:FileUpload ID="testFileUpload" runat="server" /></td><td><asp:Button ID="btnUpload" runat="server" Height="21px" Text="Upload" Width="92px" onclick="btnUpload_Click" /></td></tr>

    </table>

    <br /> 

    <asp:GridView ID="dataGridView" runat="server">

    </asp:GridView>

    </div>

    </form>



In .cs file:

    string fileName = string.Empty;

    string fileExtension = string.Empty;

    string fileLocation = string.Empty;

    string getExcelSheetName = string.Empty;

    string connectionString = string.Empty;

    DataTable dtExcelSheetName = null;

    DataTable dtExcelRecords = null;

    OleDbConnection con = null;

    OleDbCommand cmd = null;

    OleDbDataAdapter dAdapter = null;

    protected void Page_Load(object sender, EventArgs e)

    {

        cmd = new OleDbCommand();

        dtExcelRecords = new DataTable();

    }

    protected void btnUpload_Click(object sender, EventArgs e)

    {

        try

        {

            if (testFileUpload.HasFile)

            {

                fileName = Path.GetFileName(testFileUpload.PostedFile.FileName);

                fileExtension = Path.GetExtension(testFileUpload.PostedFile.FileName);

                fileLocation = Server.MapPath("~/App_Data/" + fileName);

                GetData(fileLocation);

                Label1.Text = "File is ok to upload.";

            }

        }

        catch (Exception ex)

        {

            Label1.Text = "File is not expected formated.";

        }

    }

    public void GetData(string loc)

    {

        testFileUpload.SaveAs(fileLocation);

        //Check whether file extension is xls or xslx

        if (fileExtension == ".xls")

        {

            connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + loc + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=2\"";

        }

        else if (fileExtension == ".xlsx")

        {

            connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + loc + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";

        }

        dtExcelRecords.Clear();

        dtExcelRecords.Reset();

        //Create OleDB Connection and OleDb Command

        con = new OleDbConnection(connectionString);

        cmd.CommandType = System.Data.CommandType.Text;

        cmd.Connection = con;

        dAdapter = new OleDbDataAdapter(cmd);

        con.Open();

        dtExcelSheetName = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

        getExcelSheetName = dtExcelSheetName.Rows[0]["Table_Name"].ToString();

        cmd.CommandText = "SELECT * FROM [" + getExcelSheetName + "]";

        dAdapter.SelectCommand = cmd;

        dAdapter.Fill(dtExcelRecords);

        con.Close();

        dataGridView.DataSource = dtExcelRecords;

        dataGridView.DataBind();

    }