<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="ImageId"
            DataSourceID="LinqDataSource1" Width="569px">
            <Columns>
                <asp:BoundField DataField="ImageId" HeaderText="ImageId" InsertVisible="False" ReadOnly="True"
                    SortExpression="ImageId" />
                <asp:BoundField DataField="name" HeaderText="name" SortExpression="name" />
            </Columns>
            <EmptyDataTemplate>
                <asp:Image ID="Image2" ImageUrl='<%# "ImageHendler.img?id="+"ImageId" %>' runat="server" />
            </EmptyDataTemplate>
        </asp:GridView>

    public void ProcessRequest(HttpContext context)
    {
        int id =Int32.Parse(context.Request.QueryString["Id"]);
        context.Response.ContentType = "image/jpeg";
        Stream str = StreamShowEmpImage(id);
        byte[] buffer = new byte[4096];
        int byteSeq = str.Read(buffer, 0, 4096);
        while (byteSeq>0)
        {
            context.Response.OutputStream.Write(buffer,0,byteSeq);
            byteSeq = str.Read(buffer, 0, 406);
        }...

    protected void showImageBtn_Click(object sender, EventArgs e)
    {
        Image1.ImageUrl = " ~/ImageHendler.img?Id=1";
    }