updates from another thread

Hi, I'm trying to get a label control to update with dynamic information when a timer does its tick event.

I can get it to update with information hard-coded into the tick event, but i can't seem to get any data from a global variable or other shared resource.

Here's what i have so far-

using System;using System.Data;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Threading;public partialclass _Default : System.Web.UI.Page {string temp;protected void Page_Load(object sender, EventArgs e) { }protected void Timer1_Tick(object sender, EventArgs e) { Label1.Text ="Tick at " + DateTime.Now.ToString()+"<br />";if (temp !=null) Label1.Text +="register at-"+temp; }protected void Button1_Click(object sender, EventArgs e) { Thread a =new Thread(Foo); a.Start(); }protected void Foo() {while (true) { Thread.Sleep(100); temp = DateTime.Now.Day.ToString(); } }}

(that's actually a +"<br />" at the end of the first line on the tick event)

and the markup-

<%@dotnet.itags.org. Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"> <title>Untitled Page</title></head><body> <form id="form1" runat="server"> <asp:ScriptManager ID="ScriptManager1" runat="server" /> <div> <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" /> </Triggers> </asp:UpdatePanel> </div> <asp:Timer ID="Timer1" runat="server" Interval="500" OnTick="Timer1_Tick"> </asp:Timer> <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" /> </form> </body></html>

the 'register at" text never fires. I've tried using Session and Cache variables in place of a global string but no luck.

I am not sure how it is not working when puting it in Session/Cache, would you mind posting the code?

Here's the code using session-

using System;using System.Data;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Threading;public partialclass _Default : System.Web.UI.Page {protected void Page_Load(object sender, EventArgs e) {if (!IsPostBack) Session["Store"] =null; }protected void Timer1_Tick(object sender, EventArgs e) { Label1.Text ="Tick at " + DateTime.Now.ToString()+"<br />";if (Session["Store"] !=null) Label1.Text +="register at-" + Session["Store"].ToString(); }protected void Button1_Click(object sender, EventArgs e) { Thread a =new Thread(Foo); a.Start(); }protected void Foo() {while (true) { Thread.Sleep(100); Session["Store"] = DateTime.Now.ToString(); } }}

It is not possible to access the session/request/response/cache from an different thread, also creating thread/using threadpool is not an good practise.

How should I update the label control then?

Or if using another thread is not good practice, i don't see how i'm going to be able to get the button postback to finish so i can update the label cleint side from the server during a (partial) postback

I am still not clear about your requirment, anyway here is the code snippet which will allow you to access the session from a different thread:

protected void Button1_Click(object sender, EventArgs e){ ThreadPool.QueueUserWorkItem(new WaitCallback(foo), Session);}private void foo(object state){ HttpSessionState session = (HttpSessionState)state; session["Store"] = DateTime.Now.ToString();}

Initial tests with this method provide the functionality I was after. I'll try to implament it today and let you know how it goes.

Indeed this seems to work well. I have 2 follow up questions relating to it though-

1. I went ahead and passed the session variable to other functions I use by reference...I'm guessing this is ok?

eg-

protected void Button1_Click(object sender, EventArgs e) { ThreadPool.QueueUserWorkItem(new WaitCallback(foo), Session); }private void foo(object state) { HttpSessionState session = (HttpSessionState)state; Thread.Sleep(100); session["Store"] = DateTime.Now.ToString(); Thread.Sleep(1000); foo2(ref session); }private void foo2(ref HttpSessionState session) { session["Store"] = DateTime.Now.ToString(); }

2. I notcied the application context still stays around after the browser is closed(presumably waiting for the thread to end?) should I manually be stopping the proccess somehow?

1. Yes you can pass it from the worker thread method.
2. The Thread returns to threadpool as soon as the foo2 method completes, no do not have to do anything.

Since it solved your problem, dont forget to mark it as answer.

Let's take another stab at this. You didn't really state the object of what you were trying to achieve. Why are you trying to use the variable temp? And if it truly is a shared variable, why didn't you just make it static? A Session variable certainly isn't global to the application. There's got to be a reason you're doing this and perhaps there is a much better approach.

The end result alows me to provided feekback to the cleint about a job currently being ran on the server (in psudo-real time). The timer updates the label on the client but it needs to be able to read from a variable (or somthing) that the job running on the server can write to. The session variable only needs to be global to the session (mutliple people could be using this at a time).

If there is another way to do this without using the cache or session I'd prefer too, but I havn't seen a way to do this yet...

Well there are certainly more expensive techniques such as using a Windows Service to host the job and querying it. Or using a DB entry to write the job status and querying it with a web service.

However you might be interested in this person's approach. He used a Cache object, but there is no reason it couldn't be Session (but Cache can be used if a unique identifier is set for a collection of jobs). The main difference is that his whole task is in this object, and it's public properties can be used to get it's status.

http://www.eggheadcafe.com/articles/20051223.asp

Use the Cache/ Store the Jobs status in DB as muliple user will be able to see the same result. BTW for one User you cannot use the session for storing the long running task status as the session access is always sequential.

I did try using the cache and i wasn't abe to get it to work ( see the first post). Essesntially the source looks the same as the session example except you use cache['whatever'] instead of session["whatever"].

I was under the impression that the session[] object was unique for each 'cleint session' that is, each cleint request would have it's own session object to work with. If this is the case why can't i use it for multiple users

@.wrayx1- I wanted to stay away from using a service althogh I have read some thing about how to get them to work, i think it overcompliactes the simple job I'm trying to do.

Urgent Please Help

Thanks for taking time in reading this thread.

I have Gridview contorl inside Update panel

Gridview in dynamic and I have added EditTemplateField to this grid.

When I click on Edit button , page flickers and it does not go into edit event.

I am not using sqldatasource or objectdatasource, I have custom classes.

What do you think is the problem ?

Again Thanks.

For reference here is the code

**************************************Code to create Edit button**************************************

TemplateField templateFieldEdit =newTemplateField();

templateFieldEdit.ItemTemplate =newReportViewHelper(ListItemType.Item, ReaderColumn[ReportViewHelper.ColumnDBName].ToString().Trim(),"Command");

**************************************Design Edit Button**************************************

elseif (_columnControlType =="Command")

{

ImageButton edit_button =newImageButton();

edit_button.ID ="edit_button";

edit_button.ImageUrl ="~/Images/edit.gif";

edit_button.CommandName ="Edit";

edit_button.Click +=newImageClickEventHandler(edit_button_Click);edit_button.ToolTip ="Edit";

container.Controls.Add(edit_button);

}

************************************** this is the method that is not triggering *************************************

void edit_button_Click(object sender,ImageClickEventArgs e)

{

}

Take a look at this articlehttp://aspalliance.com/1125_Dynamically_Templated_GridView_with_Edit_Delete_and_Insert_Options. It's real helpful for creating dynamic templates...

-Damien

urlrewriter and Microsoft Ajax gives me a Web Service call failed: 405

I'm using the Dynamic Populate Extender

And it gives me a

Web Service call failed: 405

Error if I'm accessing the page through a rewritten URL

featureD_properties.html
is
index.aspx?PageID=featured&agent=11

rewritten

the html one throws that error the other one doesn't...

why?

I'm using
http://www.urlrewriter.net/

you cannot use "HTML" or anything except "ASPX" as a suffix for your url when you are abut urlredirecting ,

read the PDF available on the http://www.urlrewriter.net/ it is mentioned there .

what?

I have no idea what you're talking about

The Server URL is ASPX and HTML is the URL being rewritten

The Client URL is

featureD_properties.html

and it gets rewritten to without incident

~/index.aspx?PageID=featured

That's what URLrewriting is... I think I completely missed your point or what you're trying to say....

I guess you use visual studio dev server so you can map anything but in the real world we use IIS , and IIS sends only "ASPX" files to asp.net to manage so other things (including HTML ) won't be managed by asp.net so you cannot use any other " extension " except "ASPX". Read the "readme" file on URLrewriting.net website it is clearly motioned there, though you can config your IIS to manage HTML extensions as well so you can map your addresses on HTML extensions(or anything else like .ME ! ) but usually you cannot config your hosting server !

I'm not using the dev server I'm using IIS
URLRewriting HTML extensions to a server extension on the web site is a really common practice especially in SEO scenarios

I could make the extension .Imuhhappymonkey

It doesn't matter it's just some random assortment of letters that you map to something that's it ASPX is just the default that it uses I could map ASPX to anything i want

I'm operating with dedicated Windows 2003 Servers so I can do whatever I want to to the hosting server...

The problem is that the webservices and the asmx files don't want to play nicely with the urlrewriting package...

Hi,

Please refer to this post for the explanations about why ajax extension usually has problem with URL rewriting. http://forums.asp.net/p/1153763/1890972.aspx#1890972

Use "Hello World Using Client Script" in UserControl

Hi

I want to create a asp.net user control for dynamic date entering, and I'm trying to use the same approach as in the example:

 <form runat="server">
 <div>
 Search for
 <input id="SearchKey" type="text" />
 <input id="SearchButton" type="button"
 value="Search"
 onclick="DoSearch()" />
 </div>
 </form>
 <hr style="width: 300px" />
 <div>
 <span id="Results"></span>
 </div>
 <script type="text/javascript"
 function DoSearch()
 {
 var SrchElem = document.getElementById("SearchKey");
 Samples.AspNet.HelloWorldService.HelloWorld(SrchElem.value,
 OnRequestComplete);
 }
 function OnRequestComplete(result)
 {
 var RsltElem = document.getElementById("Results");
 RsltElem.innerHTML = result;
 }
 </script>

The problem is if I use <input id=SearchKey> -tag for the result, then there will be problems if I use the same control multiple times on one page (the id is not unique, and the OnRequestComplete will update every <input>-tag with id=SearchKey). If I change it to <input id=SearchKey runat=server>, asp will render unique id's for the <input>, but then .getElementById() does not find "object".

I have done a "workaround" where I passes the object's Id to the Webservice, and returns it in an array together with the result, but I don't think this is "a great way". Is there any other solution? A better one?

function DoSearch(CallerId)
{
var SrchElem = document.getElementById(CallerId);
Samples.AspNet.HelloWorldService.HelloWorld(this.id, SrchElem.value,
OnRequestComplete);
}

function OnRequestComplete(result)
{

var objectId = result[0].toString();
var WebServiceResult = result[1].toString();
var RsltElem = document.getElementById(objectId);
RsltElem.innerHTML = result;
}

Regards

Lars K.

This is a common problem... if you use ASP.NET server IDs you need to reference the client ID in client script:

var Ctl = $('<%= SearchKey.ClientID %>');

will do the trick in finding the control reliably.

You also need to use this if use MasterPages or any contained control, so as a general rule this is the best way to reference server based page variables.

+++ Rick --

Use dynamic parameters when calling web service from javascript

Hello,

I would like to call a web services from javascript with dynamic parameters. I don't know the count and the value of the params that I'll set.

Here is a part of my code :

var serviceMethod =new Sys.Net.ServiceMethod(_servicePath, _serviceMethod, _appUrl);var paramArray =new Array(_serviceMethodParameters.length);for(var i = 0 ; i < _serviceMethodParameters.length ; i++ )

{

var toto = _serviceMethodParameters[i].get_Key();var tata = _serviceMethodParameters[i].get_Value();var elem = { toto : tata };

paramArray.push(elem);

}

_request = serviceMethod.invoke(paramArray, onMethodComplete, onMethodTimeout, onMethodError, onMethodAborted,

this , _timeoutInterval, _priority);

the problem that I have is actually I don't figure out the data format of the parameters

I would like the variable toto to be not interpreted as "toto", but as the content of the variable toto.

I could do this in another way, but I have to use this method to call a web service because I need to abort it if needed.

Any ideas about that?

Thanks in advance

Would something like this do the trick?

var elem = {};
elem[toto] = tata;
paramArray.push(elem);

Hope that helps,
-Hao

yes, it's working now, but now i've another problem : the parameter format is not correct.

When the webservice is called, it returns an error which is :

"error: Invalid object passed in, '{' expected. (1): [{\"last\":\"5000\"}]"

I actullay got it !! :)

I didn't need to use an Array to set the parameter but only a variable, kind of hashtable

I write the code if it could help someone who has the same problem.

here is the code :

var serviceMethod =new Sys.Net.ServiceMethod(_servicePath, _serviceMethod, _appUrl);var elem = {};for(var i = 0 ; i < _serviceMethodParameters.length ; i++ )

{

var toto = _serviceMethodParameters[i].get_Key();var tata = _serviceMethodParameters[i].get_Value();

elem[toto] = tata;

}

_request = serviceMethod.invoke(elem, onMethodComplete, onMethodTimeout, onMethodError, onMethodAborted,

this ,_timeoutInterval, _priority);