How to check if request is ajax or not in codebehind - ASP.NET Webforms

Question

I tried the Request.IsAjaxRequest but this does not exist in WebForms. I am making a JQuery ajax call. How do I check if this is a ajax request or not in C#?

Answer 1

I created an extension that I use:

internal static bool IsAjaxRequest(this HttpRequestMessage request)
{
    return request != null && request.Headers.Any(h => h.Key.Equals("X-Requested-With", StringComparison.CurrentCultureIgnoreCase) &&
        h.Value.Any(v => v.Equals("XMLHttpRequest", StringComparison.CurrentCultureIgnoreCase)));
}

Answer 2

Decorate your class with [WebMethod(EnableSession = true)]syntax like if you write the following function in code behind and call the same function from ajax call you will be sure.

[WebMethod(EnableSession = true)]
    public static void   getData(string JSONFirstData,string JSONSecondData, string JSONThirdData, string JSONForthData, ...)
    {
       //code
    }

in Ajax URL be like URL :'/Codebehind.aspx/getData'

Answer 3

Yes, Request.IsAjaxRequest looks at the headers and the querystring for X-Requested-With, but it seems your jquery isn't sending the X-Requested-With header.

You can try and see what headers it is sending by using Fiddler, or alternatively just send it in the querystring by setting the POST url to

/whatever.aspx?x-requested-with=XMLHttpRequest

Answer 4

You could create your own extension method much like the one in the MVC code

E.g.

public static bool IsAjaxRequest(this HttpRequest request)
{
    if (request == null)
    {
        throw new ArgumentNullException("request");
    }

    return (request["X-Requested-With"] == "XMLHttpRequest") || ((request.Headers != null) && (request.Headers["X-Requested-With"] == "XMLHttpRequest"));
}

HTHs,
Charles

Edit: Actually Callback requests are also ajax requests,

    public static bool IsAjaxRequest(this HttpRequest request)
    {
        if (request == null)
        {
            throw new ArgumentNullException("request");
        }
        var context = HttpContext.Current;
        var isCallbackRequest = false;// callback requests are ajax requests
        if (context != null && context.CurrentHandler != null && context.CurrentHandler is System.Web.UI.Page)
        {
            isCallbackRequest = ((System.Web.UI.Page)context.CurrentHandler).IsCallback;
        }
        return isCallbackRequest || (request["X-Requested-With"] == "XMLHttpRequest") || (request.Headers["X-Requested-With"] == "XMLHttpRequest");
    }

Answer 5

Try to check if the ScriptManager IsInAsyncPostBack :

ScriptManager.GetCurrent(Page).IsInAsyncPostBack

Answer 6

Generally, you will need to test for the X-Requested-With header, ensuring that its value is 'XMLHttpRequest'. I'm not a C# developer (yet), but a quick google search says that in C# it goes something like this:

Request.Headers["X-Requested-With"] == "XMLHttpRequest";