Image not showing in webpage with image control in datagrid

Question

Here is my requirements. my database contain few fields along with image data as bytes. Now i have webpage i can filter the data with few filters and show the images in the grid view along with the data.

I wrote my code as below, all other data is showing fine in the webpage but for Images it is showing blank. in debug mode i verified it showing some bytes of information for image. I am not receiving any error messages as well. I am confused what went wrong with my code.

Please help

 

 My class:

public class Expense
{
public string ID { get; set; }
public DateTime StartTimeStamp { get; set; }
public double ExpenseAmt { get; set; }
 public byte[] Photo { get; set; }
}

My Button click event along with method:

protected void Button1_Click(object sender, EventArgs e)
    {
        List<expense> exps = getSQLData();
        GridViewImage.DataSource = exps;
        GridViewImage.DataBind();
   }

public List<expense> getSQLData()
    {
        List<expense> Expenses = new List<expense>();
        string cs = ConfigurationManager.ConnectionStrings["test"].ConnectionString;

        using (SqlConnection conn = new SqlConnection(cs))
        {
            SqlCommand cmd = new SqlCommand("Select ID, Start_Timestamp,  Expense_Amt, Receipt_Photo from EXPENSE where id='testing'", conn);
            conn.Open();
            SqlDataReader rdr = cmd.ExecuteReader();
            while (rdr.Read())
            {
                Expense exp = new Expense();

                exp.ID = rdr[0].ToString();
                exp.StartTimeStamp = Convert.ToDateTime(rdr[1].ToString());
                exp.ExpenseAmt = Convert.ToDouble(rdr[2].ToString());
                exp.Photo = (byte[])rdr[3];

                Expenses.Add(exp);

            }
        }

        return Expenses;
    }

My Gridview code in my aspx file:

<asp:GridView ID="GridViewImage" runat="server" AutoGenerateColumns="false">
<columns>
    <asp:BoundField DataField="ID" HeaderText="EnterpriseID" />
    <asp:BoundField DataField="StartTimeStamp" HeaderText="StartTimeStamp" />
    <asp:BoundField DataField="ExpenseAmt" HeaderText="ExpenseAmt" />
    <asp:TemplateField HeaderText="Photo">
        <itemtemplate>
            <asp:Image ID="ReceiptImage" runat="server" Height="500px" Width="500px"
                ImageUrl ='<%# "data:image/jpg;base64," + Convert.ToBase64String((byte[])Eval("Photo")) %>'>


        </itemtemplate>