如何从ASPX文件中的代码后面输出XML？

Question

I need to output XML / ASX on an ASPX page. The XML is generated from the code behind and will look like this .

I'm using string builder to create the XML / ASX.

            (...)
            sb.AppendLine("<asx version='3.0'>");
            sb.AppendLine("<title> Spilliste </title>");
            while (i < pdc.Count)
            {
                sb.AppendLine("<entry>");
                sb.AppendLine("<title>" + pdc[i].PageName + "</title>");
                sb.AppendLine("<abstract> Ikke tilgjengelig</abstract>");
                sb.AppendLine("<ref>" + pdc[i].LinkURL + "</ref>");
                sb.AppendLine("</entry>");
                i++;
            }
            sb.AppendLine("</asx>");

            return sb.ToString();
            (...)

But how can I output this?

Response.Write does not work from code behind. And I'm notable to use <asp:label> in the ASPX file, because it needs to be placed within tags. I basically have a blank ASPX page.

What to do?

Answer 1

Don't use a Page for this. Basically Page s are for rendering html. If you want to send xml or images or any other type of data for that matter you should use a .ashx file and and a class that implements IHttpHandler .

You can see this example on how to implement the interface.

Answer 2

    Response.ClearHeaders();
    Response.ContentType = "text/xml;charset=UTF-8";
    string xmlString = "<aaa>sai</aaa>";
    Response.Write(xmlString);
    Response.End();

Answer 3

Response.Write should work from code behind:

  Response.Write("some test");
  Response.Flush();

But you should execute this code in Page_Load method. You should prepare separate aspx page for generating xml and redirect user that page. This page should be empty (only <%@ ... %> in aspx file).

Answer 4

You should use an IHttpHandler for this - you can configure which URL's it handles either by making an .ashx file (very simple) or by registering them in the web.config file , which is more flexible, but trickier since the syntax various between classic and integrated mode IIS.

Then, you'll need a simple class with one important member - a ProcessRequest method taking only one parameter - the HttpContext.

Further, avoid using a StringBuilder to build XML. You can use the safer and more flexible linq to xml classes instead: Using this type-safe approach also makes it way easier to write helper methods to generate parts of the xml tree correctly; and you can query and transform the results to boot.

void ProcessRequest(HttpContext context) {
    var pdc = Enumerable.Range(0,10).Select(
        i=>new{PageName="Page"+i,LinkURL="Link"+i});                

    var xmlString = 
    new XElement("asx",
        new XAttribute("version","3.0"),
        new XElement("title","Spilliste"),
        pdc.Select(pdcElem=>
            new XElement("entry",
                new XElement("title",pdcElem.PageName),
                new XElement("abstract","Ikke tilgjengelig"),
                new XElement("ref",pdcElem.LinkURL)
            )
        )
    ).ToString(SaveOptions.DisableFormatting);

    //don't forget to handle headers and set things like content-type too!
    context.Response.Write(xmlString);
}

The reason this approach is better than hacking around a .aspx file is that although it's possible in a .aspx file, you'll need to fight the framework to get there - a whole bunch of infrastructure will get in your way, perhaps subtly mangling your output before it reaches the client. The easiest way to get rid of that is by using a more bare-to-the-metal handler that isn't specifically intended to host aspx controls and generate HTML.