This MSDN example for an Asynchronous Handler starts the new thread using ThreadPool.QueueUserWorkItem.
I thought that you should not use ThreadPool.QueueUserWorkItem to start the new thread as the thread is taken from the ASP.net thread pool and defeats the purpose of using an Asynchronous handler.
Is the example wrong?
after invoking an async method using ThreadPool.QueueUserWorkItem how do i lookup the assigned thread id?
View 4 RepliesIn an async http handler, we add items to the ASP.NET cache, with dependencies on some files. If the async method executes on a thread from the ThreadPool, all is fine:
AsyncResult result = new AsyncResult(context, cb, extraData);
ThreadPool.QueueUserWorkItem(new WaitCallBack(DoProcessRequest), result);
But as soon as we try to execute on a thread out of the ThreadPool:
AsyncResult result = new AsyncResult(context, cb, extraData);
Runner runner = new Runner(result);
Thread thread = new Thread(new ThreadStart(runner.Run());
... where Runner.Run just invokes DoProcessRequest,
The dependencies do trigger right after the thread exits. I.e. the items are immediately removed from the cache, the reason being the dependencies.We want to use an out-of-pool thread because the processing might take a long time.
So obviously something's missing when we create the thread. We might need to propagate the call context, the http context...
Note: off-the-shelf custom threadpools probably solve this. Writing our own threadpool is probably a bad idea (think NIH syndrom). Yet I'd like to understand this in details, though.
This may be due to a lack of understanding of what's going on under the hood or simply a lack of understanding of threading in general. When a user logins I need to run some tasks that call web services to update data in my system. Since the services could take a considerable amount of time I thread the entire process. However, even though I think I'm running the whole series of tasks in a thread separate from my application, my application waits until the called function is finished before it proceeds.
WindowsIdentity identity = WindowsIdentity.GetCurrent();
Manager manager = (Manager)Session["Manager"];
ThreadPool.QueueUserWorkItem(new SafeWaitCallback().Call(identity, delegate(object noCallBack)
{
manager.RunAccountUpdater(identity);
}));
The application hangs until the function "RunAccountUpdater" is finished and the callback occurs. What am I doing wrong/not understanding?
From a web page I start a time consuming job and update it's status on the UI using webmethod.
Job is done in a thread:
ThreadPool.QueueUserWorkItem(new WaitCallback(DoJob), parameters); Job set's it status using static properties, and when web page, using javascript, calls web method it read those properties.
[System.Web.Services.WebMethod]
public static ProcessStatus GetProgressStatus()
{
Jober.Lock.EnterReadLock();
ProcessStatus st = new ProcessStatus(Jober.PercentageCompleted, Jober.TotalNumber);
Jober.Lock.ExitReadLock();
return st;
}
The UI progress is updated through javascript, the problem is that after thread completes I need to update UI on server side, so javascript won't help me here. What Is the best way to signal when thread is completed?
I have a web service that uses ThreadPool to delegate a task to a thread but it runs on ASPNET (System.Environment.UserName) while the main thread runs as windows account. How can I make this thread run with same windows account. Note that I have impersonate=true in web.config. This is causing problems accessing database.
View 1 RepliesMy application is a asp.net 3.5 running on iis 6 (windows 2003)
This application is serving 1000's of users daily (100-500 users online).
I want to send an email newsletter to customers weekly.
Around 200,000 emails every time.
This is the code im using:
ThreadPool.QueueUserWorkItem(new WaitCallback(AsyncProcessMailerQueue), null);
private static void AsyncProcessMailerQueue(object data)[code]....
When testing this locally (on my dev machine) i see the application is working alot slower.
Is there a better way to write this code? Should i use ThreadPool.QueueUserWorkItem or create a new thread using Thread t = new Thread(new ThreadStart(DoWork)); ? Will it be better to create a totally seperate application for the purpose of sending the newsletters. will that help if ill run this application on the same machine?
i've seen other posts here talking about ThreadPool vs Thread but its seem no one is sure which is better.
Am implementing the threadpool concept and have doutbt in threads being created.
[Code]....
Initially i gave (1,1) in semaphores and only one thread was created and it did only one task, and (5,5) created one thread and it used for all the times.
Is ter anything wrong in wat i did or any other way of doin other than semaphores. And mainly wat abt the remaining 20 threads in threadpool? its a waste of CPU right. Can i create only 5?
I create custom HTTP handler for auto generating file and I want to tell IIS7 to serve current request like normal static file because I need to use IIS and web.config file to control compression setting and any other HTTP header of current requested file.I know. there is an internal class called StaticFileHandler in ASP.net. But I cannot access it. Or you have any other way to work like this.
View 1 RepliesIs there a technical reason for the existence of Page.PreLoad or is this just convenience to have a place where you can neatly place code that always have to be executed before the Load code? Is there a difference between adding code in the PreLoad event handler and adding code at the top of the Load event handler? And what would be a typical scenario where you use PreLoad?
View 2 RepliesIn Visual Studio 2010, when you say new Item, you can see Asp.NET Handler and Generic Handler. Can you tell me what's the difference, I think it came with .NET 4.0 because I couldn't find related thins on Google.
View 1 RepliesI used to build my web apps in asp.net in such there is only one page witch is default.aspx
http://localhost/mywebapp1/?q=blog/posts/get/42
I do parse 'q' by myself and do all processing. I don't really need to all MVC staff. I just want to remove "?q="
I need to update the handler mappings on IIS 7.5 to allow URLs that don't have extensions to be routed to an application. The application was originally written in ASP.NET 2.0, but then later upgraded to ASP.NET 3.5. I don't know if that has relevance, but I've had no problem updating handler mappings for other .net 3.5 apps before. I should also note that this works fine on IIS 6.0
This is the error message I get when I click the Handler Mappings link in IIS 7.5 (notice there isn't really an error message as such, which would be helpful):
Handler Mappings
There was an error while performing this operation.
Details:
Filename: ?D:path oweb.config
Error:
OK
Has anyone seen this before? If you need more info, let me know and I'll supply.
I'm trying to write an HTTP GET handler. The path should start with http://site/processTask and have a set of URL-encoded parameters. I have the following in my web.config
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
<add verb="GET" path="processTask*" type="MyHandler.ProcessTaskHandler, MyHandler"/>
</httpHandlers>
now when I type the URL http://mysite/processTask in browser I get HTTP 404 but if I change the add verb line to the following one:
<add verb="GET" path="processTask.asmx*" type="MyHandler.ProcessTaskHandler, MyHandler"/>
and type http://mysite/ProcessTask.asmx in browser the handler is run and I get the response from the handler. What's the problem? Why is the handler run only when the path contains .asmx? How do I change web.config so that .asmx is not required?
I've got a simple ASHX handler that returns an dynamically generated image; the image is generated from a custom created class, and an object belonging to this class is passed to the handler using Session (I'd rather avoid using QueryString).The handler is used as the URL of an image on a ASP form which is very simple: a drop down list, a button and an image. Basically, depending on what the user selects from the list, the appropriate image will be generated once the button is pressed.
At the start the actual image has it's Visible property set to false; I don't want the handler to display anything before the data is all there.Once the button is pressed, the required Session parameter is added containing the necessary object, and the page is refreshed using Server.Transfer. When the Page_load method detects that the Session parameter has been correctly set, it sets the Visible parameter on the image to true.After that the handler fires up and generates the image.
So far so good... However, if the user now picks something different from the list and presses the button, despite the correct object being passed in the Session, the image won't be updated. In fact, the handler won't even fire up (if I put a breakpoint in there). I need to close the browser window and reopen it for it to work.Any ideas what could be the cause of such behaviour?I suspect the answer is very simple, and I just don't know something fundamental about ASP (or handlers)...
I am using ASP.NET Callbacks (that implements the ICallbackEventHandler) and in the handler, I try to set a value of the text box:
txtName.text = "Test";
but this value is not set. Is this a limitation with callback? It appears I cannot do much in a callback handler other than sending back a string to the client side (ofcourse I can access the Session etc)
Here's what I want to do:
I've created a class library project
and this has a class implementing
the IHttpHandler interface. Let's
call this class ZipHandler. Let's
say the namespace is Zip.
I want that whenever any Http
request comes for a zip file, my
ZipHandler should handle it,
regardless of whether the request is
to an Asp.Net application or a
normal virtual directory.
Queries:
Is it possible (it should be given
the hype about integrated pipeline
etc. in IIS 7)?
How to do it?
The code below is a handler to allow variables in css files. Works fine except when, as shown, I need to retrieve a value from the mvc route. In the code below the variable "Forum" is a route value.
What code do I need in this handler to retrieve the route value of Forum?
[Code]....
I've created a database table with a bunch of links I'm going to use in my program. All seems fine, except for the onClick even handler, which doesn't work as a string. Anyone got an idea how I can set it? There's no constructor for EventHandler accepting a string...
View 4 Repliesi write a html code for file saveas using file uploading control. here file saveas working for aspx code but not working for html code to call handler(ashx).
View 1 Repliesive a user control with several checkboxes, each control (only check boxes) has its own click even handler:
[Code]....
when the user click one of the checkboxes the even is triggered and some code is run correctly.
on my page the user control has its own mouseclick event, i need both to expose the checkbox click event or propagate it to the user control click
I Have a generic handler that's serving member logo images:
http://site.com/logo.ashx?memberid=123
Now, I want to use it by caling a url like:
http://site.com/logo/john.jpg
So I would create a route for that (pattern: "logo/{username}.jpg"). But, my problem is - how do I retrieve {username} when inside ProcessRequest() of my generic handler? It's not a page, so I can't get Page.RouteData.Values.
I have an older classic ASP website that I am migrating over to IIS7.5. I don't feel like installing classic ASP on the server, and so I just want the .asp files to be treated as if they were .aspx files.
How do I go about doing this in IIS7.5?
EDIT: To clarify, I am NOT asking how to get classic ASP code to work under .Net. I am just asking how to map the .ASP file extension to be handled by the .net runtime. I will upgrade the code in the .asp files to .net.
EDIT:
I gave up and ended up installing classic ASP, as I couldn't get the mapping to work (received a combination of 404.17 and 404.3 errors). I marked David Lively's answer as correct as it was the most detailed and helpful.
In desktop programming, I can usually find out which control has fired an event via using the following coding:
[Code]....
However in ASP.Net, button derives from System.Web.UI.WebControls.Button an does not feature an extension method for Name, therefore can anyone come up within something similar that will work in ASP?
I am creating a web control by addin the html in the code behind, like this:
Code:
Dim sb As New StringBuilder
Dim myDiv As HtmlGenericControl = Me.theContainer
sb.Append("<table width='100%' cellpadding='0' cellspacing='0' style='border:0px;'>" & vbCrLf)
sb.Append(" <tr class='mainRow1'>" & vbCrLf)
sb.Append("<td align='left' style='border:0px solid white;'>Main Menu</td>" & vbCrLf)
[Code] ....
This will generate the html for the table in the codebehind then inject it into the specified DIV element. My question is, if I create a control in this manner, how do i add an event that will fire a method in my codebehind? For example, if i want to create a image button i would do it this way in the code:
Code:
<asp:ImageButton CommandArgument='<%# (Container.DataItem.objectValue) %>'
ID='ImageButton1' runat='server' OnCommand='Button1_Click' ImageUrl='~/images/folder.gif' />
but in the code behind i would do this:
Code:
sb.Append("<input type='image' name='ctl00$ContentPlaceHolder1$importWizard1$folderControl1$folderRepeater$ctl04$ImageButton" & myCounter & "'")
sb.Append(" id='ctl00_ContentPlaceHolder1_importWizard1_folderControl1_folderRepeater_ctl04_ImageButton" & myCounter & "'")
sb.Append(" src='images/folder.gif' style='border-width:0px;' />" & vbCrLf)
But I cant add the OnCommand because it wont be rendered properly.