Question

page.aspx.cs code:

HttpContext.Current.Session["id1"] = id1.ToString();
Server.Transfer("Handler.ashx"); //Getting error
Image1.ImageUrl = "~/Handler.ashx?ID=" + id1.ToString();

HttpContext.Current.Session["id2"] = id2.ToString();
Server.Transfer("Handler.ashx"); //Getting error
Image2.ImageUrl = "~/Handler.ashx?ID=" + id2.ToString();

Handler.ashx code:

public void ProcessRequest(HttpContext context)
{
    int id = Convert.ToInt32(context.Session["id1"]);
    byte[] IMG = class.ReadImg(id);
    context.Response.ContentType = "image/jpg";
    context.Response.BinaryWrite(IMG);
}
public void ProcessRequest2(HttpContext context2)
{
    int id = Convert.ToInt32(context2.Session["id2"]);
    byte[] IMG2 = class.ReadImg(id);
    context2.Response.ContentType = "image/jpg";
    context2.Response.BinaryWrite(IMG2);
}

page.aspx code:

<asp:Image ID="Image1" runat="server" />//How to define thats gonna show image of id1
<asp:Image ID="Image2" runat="server" />//How to define thats gonna show image of id2

Question:

1. I’m not able to transfer data from page.aspx to Handler.ashx
2. I dont know how to make Image element to identify which image it should show according to the id (maybe some request.queryString magic I don’t understand)

Help!!
Thanks :]

Answer 1

Server.Transfer() does what it says – transfer the request on the server-side, without returning a HTTP 301 re-direct to the client.

Your problem can be solved by simply reading the querystring in the ashx file:

string id = context.Request.Querystring["ID"];
context.Response.ContentType="image/jpeg";
......

Then in your aspx page:

Image1.ImageUrl = "/Handler.ashx?ID="+id.ToString();