I just find that the problem is not related to the webmethod.
It is caused by another problem.
I set the Session["PhotoId"] in a normal aspx.
But I can't retrieve value in the webMethod of the aspx page.
[WebMethod(EnableSession=true)]
public static string Submit(string data1, ...)
{
string test = HttpContext.Current.Session["PhotoId"]; // test is null
}
What should I do?
As I see, everything should be fine here.
As far as HttpContext.Current.Session is not null, session state is supported here.
Please ensure, that you set Session["PhotoId"].
You can test whether it is the same session by examining
HttpContext.Current.Session.SessionID
in both normal ASPX and WebMethod.
You should use ToString() method to use session as a string.
[WebMethod(EnableSession=true)]
public static string Submit(string data1, ...)
{
string test = HttpContext.Current.Session["PhotoId"].ToString();
}
Related
Maybe a stupid question. C# 6.0 allows for string replacement using this syntax: $"string content {foo} {bar}". I would like to imitate this behavior in a class I've written for strings passed to it by default. The problem is that I am not sure how to access the public properties/variables. I am not sure if there is a way to access the properties using reflection or by passing this or this.Page to the constructor.
Figured it out:
public static object GetPropValue(object src, string propName)
{
return src.GetType().GetProperty(propName).GetValue(src, null);
}
object UID = GetPropValue(System.Web.HttpContext.Current.Handler, "UID");
I have a webforms project, and am attempting to run some code that allows me to make a call to an MVC route and then render the result within the body of the web forms page.
There are a couple of HttpResponse/Request/Context wrappers which I use to execute a call to an MVC route, e.g.:
private static string RenderInternal(string path)
{
var responseWriter = new StringWriter();
var mvcResponse = new MvcPlayerHttpResponseWrapper(responseWriter, PageRenderer.CurrentPageId);
var mvcRequest = new MvcPlayerHttpRequestWrapper(Request, path);
var mvcContext = new MvcPlayerHttpContextWrapper(Context, mvcResponse, mvcRequest);
lock (HttpContext.Current)
{
new MvcHttpHandlerWrapper().PublicProcessRequest(mvcContext);
}
...
The code works fine for executing simple MVC routes, for e.g. "/Home/Index". But I can't specify any query string parameters (e.g. "/Home/Index?foo=bar") as they simply get ignored. I have tried to set the QueryString directly within the RequestWrapper instance, like so:
public class MvcPlayerHttpRequestWrapper : HttpRequestWrapper
{
private readonly string _path;
private readonly NameValueCollection query = new NameValueCollection();
public MvcPlayerHttpRequestWrapper(HttpRequest httpRequest, string path)
: base(httpRequest)
{
var parts = path.Split('?');
if (parts.Length > 1)
{
query = ExtractQueryString(parts[1]);
}
_path = parts[0];
}
public override string Path
{
get
{
return _path;
}
}
public override NameValueCollection QueryString
{
get
{
return query;
}
}
...
When debugging I can see the correct values are in the "request.QueryString", but the values never get bound to the method parameter.
Does anyone know how QueryString values are used and bound from an http request to an MVC controller action?
It seems like the handling of the QueryString value is more complex than I anticipated. I have a limited knowledge of the internals of the MVC Request pipeline.
I have been trying to research the internals myself and will continue to do so. If I find anything I will update this post appropriately.
I have also created a very simple web forms project containing only the code needed to produce this problem and have shared it via dropbox: https://www.dropbox.com/s/vi6erzw24813zq1/StackMvcGetQuestion.zip
The project simply contains one Default.aspx page, a Controller, and the MvcWrapper class used to render out the result of an MVC path. If you look at the Default.aspx.cs you will see a route path containing a querystring parameter is passed in, but it never binds against the parameter on the action.
As a quick reference, here are some extracts from that web project.
The controller:
public class HomeController : Controller
{
public ActionResult Index(string foo)
{
return Content(string.Format("<p>foo = {0}</p>", foo));
}
}
The Default.aspx page:
protected void Page_Load(object sender, EventArgs e)
{
string path = "/Home/Index?foo=baz";
divMvcOutput.InnerHtml = MvcWrapper.MvcPlayerFunctions.Render(path);
}
I have been struggling with this for quite a while now, so would appreciate any advice in any form. :)
MVC framework will try to fill the values of the parameters of the action method from the query string (and other available data such as posted form fields, etc.), that part you got right. The part you missed is that it does so by matching the name of the parameter with the value names passed in. So if you have a method MyMethod in Controller MyController with the signature:
public ActionResult MyMethod(string Path)
{
//Some code goes here
}
The query string (or one of the other sources of variables) must contain a variable named "Path" for the framework to be able to detect it. The query string should be /MyController/MyMethod?Path=Baz
Ok. This was a long debugging session :) and this will be a long response, so bear with me :)
First how MVC works. When you call an action method with input parameters, the framework will call a class called "DefaultModelBinder" that will try and provide a value for each basic type (int, long, etc.) and instance of complex types (objects). This model binder will depend on something called the ValueProvider collection to look for variable names in query string, submitted forms, etc. One of the ValueProviders that interests us the most is the QueryStringValueProvider. As you can guess, it gets the variables defined in the query string. Deep inside the framework, this class calls HttpContext.Current to retrieve the values of the query string instead of relying on the ones being passed to it. In your setup this is causing it to see the original request with localhost:xxxx/Default.aspx as the underlying request causing it to see an empty query string. In fact inside the Action method (Bar in your case) you can get the value this.QueryString["variable"] and it will have the right value.
I modified the Player.cs file to use a web client to make a call to an MVC application running in a separate copy of VS and it worked perfectly. So I suggest you run your mvc application separately and call into it and it should work fine.
I have an action, let's say /Foo/Bar with a GET parameter in this action,
get_cached, who define if we want to get the cached value or the "realtime".
This is made with the following code :
public ActionResult Bar()
{
var useCache = Request.Params["get_cached"] == "1" ? true : false;
if (useCache)
{
return RedirectToAction("BarCached");
}
else
{
return RedirectToAction("BarRealTime");
}
}
[OutputCache(Duration = 100, VaryByParam = "*")]
public ActionResult BarCached()
{
return Content("mystuff_cached");
}
public ActionResult BarRealTime()
{
return Content("mystuff_realtime");
}
No problem with this code, apart the url will be shown as BarCached or BarRealTime and i would get only Bar (the main action name).
I tried to change the RedirectToAction to the full method name like this :
return this.BarCached()
But this disable the cache capabilities !
So, how can render the ActionResult code from a method (render BarCached from Bar) using the OutputCache definitions on this method (OutputCache on BarCached) ?
Thanks by advance.
In the asp.net pipeline, ResolveRequestCache (which OutputCache relies on) occurs just after the request is authenticated. In your example above, by the time you have gotten to "Bar" it's too late to use output caching, as you have noted by saying that this.BarCached() doesn't recognize the cache attribute.
If your problem is the performance of whatever generates "mystuff_", could you not just save the result of that call to the application cache and return it in your Bar() method instead of the RedirectToAction objects?
Not much of a solution I know, but hopefully helpful just the same.
I ended using the System.Web.Caching namespace who is the base cache handler of asp.net MVC.
I can access the cache repository of Asp.NET MVC with System.Web.HttpContext.Current.Cache
Using that, I store the ActionResult of "BarCached" and then I can get the cache feature the way I want using something like this :
Add a value to the cache
System.Web.HttpContext.Current.Cache.Insert(
"mykey",
"myvalue",
null,
DateTime.Now.AddSeconds(expirationInSeconds),
System.Web.Caching.Cache.NoSlidingExpiration
);
And get value from the cache
var myvalue = System.Web.HttpContext.Current.Cache.Get("mykey")
Ok, so I can't seem to find decent Windows Azure examples. I have a simple hello world application that's based on this tutorial. I want to have custom output instead of JSON or XML. So I created my interface like:
[ServiceContract]
public interface IService
{
[OperationContract]
[WebInvoke(UriTemplate = "session/create", Method = "POST")]
string createSession();
}
public class MyService : IService
{
public string createSession()
{
// get access to POST data here: user, pass
string sessionid = Session.Create(user, pass);
return "sessionid=" + sessionid;
}
}
For the life of me, I can't seem to figure out how to access the POST data. Please help. Thanks!
If you have an HttpContext there may be a Request object that would have the form data. I'm basing part of this off the ASP.Net tag on this question, so if that is incorrect then there may be the need to handle this another way but it looks a lot like a web service to my mind.
EDIT: HttpRequest is the class that has the Form property that should be where the POST data is stored if this is an HTTP request. This is part of System.Web so it should be ready to be used pretty easily, as I recall.
Sample code showing the Request.Form property:
int loop1;
NameValueCollection coll;
//Load Form variables into NameValueCollection variable.
coll=Request.Form;
// Get names of all forms into a string array.
String[] arr1 = coll.AllKeys;
for (loop1 = 0; loop1 < arr1.Length; loop1++)
{
Response.Write("Form: " + arr1[loop1] + "<br>");
}
This presumed there was an HttpRequest instance around.
WCF Simplified Part 4: Comparing the Request/Reply and One-Way Patterns passes in a parameter so that your "createSession" method would have to take in those strings it would appear. I'm used to the ASP.Net world where there are some built-in objects like Request, Response, Server, Application and Session.
Yes, if you did try changing the method signature as there are ways to pass in parameters in that last example I linked though I don't know if that would work in your case or not.
I have the following web service:
[ScriptService]
public class Handler : WebService {
[WebMethod]
public void method1() {
string json = "{ \"success\": true }";
System.Web.HttpContext.Current.Response.Write(json);
}
[WebMethod]
public object method2(Dictionary<string, object> d) {
Dictionary<string, object> response = new Dictionary<string, object>();
response.Add("success", true);
return response;
}
}
The first method accepts a traditional html form post and response writes a JSON string to the page. The second method accepts a JSON value posted via AJAX and returns a serialized object.
Both these methods work fine on their own but when put together in the same web service I get this error when calling method1:
System.IndexOutOfRangeException: Index was outside the bounds of the array.
When I remove the arguments from method2 they work.
Can anyone suggest why this is happening?
Edit:
The problem spans from the argument type of method2. If I change it to a string or simple data type it works fine. As Joel suggests it's probably because Dictionaries can't be serialized. This doesn't seem to affect my requests sent by ajax and only breaks direct form posts to this handler. Therefore my workaround is to put the form post handlers in a separate file by themselves. Not ideal but works for my application.
Dictionaries are not serializable. Hiding it behind an object doesn't do anything for you. You must first convert your dictionary to an array or some other serializable object before sending it out.
Why isn't there an XML-serializable dictionary in .NET?
http://weblogs.asp.net/pwelter34/archive/2006/05/03/444961.aspx
http://www.tanguay.info/web/index.php?pg=codeExamples&id=333