Displaying Image from database to gridview

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ASP.NET

.NET

handler

I am trying to get images from database and uses a handler for it.
code are as follows
on my aspx page

<asp:GridView ID="GridView2" runat="server" AllowPaging="True"
                            AutoGenerateColumns="False" DataKeyNames="ID"
                            DataSourceID="SqlDataSourceGridView">
                            <Columns>
                                <asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False"
                                    ReadOnly="True" SortExpression="ID" />
                                <asp:BoundField DataField="ImageTitle" HeaderText="ImageTitle"
                                    SortExpression="ImageTitle" />
                                    <asp:TemplateField HeaderText="Image">
                                <ItemTemplate>
                                <asp:Image ID="Image1" runat="server"
                                ImageUrl='<%# "HandlerCategory1.ashx?ID=" & Eval("ID")%>'/>
                                </ItemTemplate>
                                    </asp:TemplateField>

                            </Columns>
                        </asp:GridView>

and on my HandlerCategory

Dim con As New SqlConnection()
      con.ConnectionString = ConfigurationManager.ConnectionStrings("MyConnectionString").ConnectionString

      ' Create SQL Command

      Dim cmd As New SqlCommand()
      cmd.CommandText = "Select ImageTitle,Image from Images where ID =@ID"
      cmd.CommandType = System.Data.CommandType.Text
      cmd.Connection = con

      Dim ImageID As New SqlParameter("@ID", System.Data.SqlDbType.Int)
      ImageID.Value = context.Request.QueryString("ID")
      cmd.Parameters.Add(ImageID)
      con.Open()
      Dim dReader As SqlDataReader = cmd.ExecuteReader()
      dReader.Read()
      context.Response.BinaryWrite(DirectCast(dReader("Image"), Byte()))
      dReader.Close()
      con.Close()
  End Sub

Now I am getting a null value on context.Request.QueryString that I am getting an error.
Is there something wrong on my code?