WP7 HttpWebRequest without caching - caching

Question

It seems that HttpWebRequest caching in WP7 is enabled by default, how do I turn it off?
Adding a random
param url + "?param=" + RND.Next(10000) works, but it's quite tricky and I'm not sure if it will work
with all servers.

Answer 1

For future reference , this worked for me ( I could not use additional query parameter due to project requirements) :
HttpWebRequest request = HttpWebRequest.CreateHttp(url);
if (request.Headers == null)
{
request.Headers = new WebHeaderCollection();
}
request.Headers[HttpRequestHeader.IfModifiedSince] = DateTime.UtcNow.ToString();

Answer 2

In case of HttpClient (Portable for Windows Phone) "Cache-Control": "no-cache" on server side works only sometimes. And I cannot add query string random value to RESTful api call as well.
Solution from #frno works good and looks like for HttpClient:
client.DefaultRequestHeaders.IfModifiedSince = DateTime.UtcNow;
Thank you.

Answer 3

How do you know it's the phone, not the server (or a proxy somewhere between) which is caching?
Have you checked this with Fiddler2 (or equivalent)?
Have you tried setting headers to disable caching?
Something like:
myRequest = (HttpWebRequest)WebRequest.Create(myUri);
myRequest.Headers["Cache-Control"] = "no-cache";
myRequest.Headers["Pragma"] = "no-cache";

Answer 4

We've seen the same behaviour with Silverlight hosted in Chrome.
We add a "?nocache=" + DateTime.Now.Ticks.ToString() to our request URLs if we want to prevent caching.

Answer 5

I found 3 ways
Add a random Query String to the end of your URI (think Guid.NewGuid()) this will avoid caching on the client as the Query String will be different each time
string uri = "http://host.com/path?cache="+Guid.NewGuid().ToString();
Specify no cache in the OutgoingResponse header within your WCF service operation:
var __request = (HttpWebRequest)WebRequest.Create(url.ToString());
if (__request.Headers == null)
__request.Headers = new WebHeaderCollection();
__request.Headers.Add("Cache-Control", "no-cache");
markup your service operation with the AspNetCacheProfile attribute:
[AspNetCacheProfile("GetContent")]
public ResultABC GetContent(string abc)
{
__request = (HttpWebRequest)WebRequest.Create(abc);
return __request;
}
And update your web.config
<system.web>
<caching>
<outputCache enableOutputCache="true" />
<outputCacheSettings>
<outputCacheProfiles >
<add name="GetContent" duration="0" noStore="true" location="Client" varyByParam="" enabled="true"/>
</outputCacheProfiles>
</outputCacheSettings>
</caching>
...
</system.web>

Answer 6

Adding random number is not bad and it will work. I have used Time (in ajax call). Was placed in the url like a folder.

Answer 7

Yes is possible... :) I spend one week of Experiment and the answer is really simple :
HttpWebRequest _webRequest = WebRequest.CreateHttp(_currentUrl);
_webRequest.AllowReadStreamBuffering = false
_webRequest.BeginGetResponse(_onDownload,
userState);