I am trying to get my program to read async so it doesn't just freeze up while it fetches the data. I have:
SR = New StreamReader(WC.OpenReadAsync(New Uri(url)))
Dim html = SR.ReadToEnd.ToString
It keeps throwing the error "does not produce an expression". I remember trying this in the past, only to have the same error.
trying to write a dynamic sql query that fetches data from oracle 10g database. My Where criteria is giving me real problems but i guess it has to do with the oracle data format. The data column is a TIMESTAMP data type storing values like 25-JAN-09 07.06.01.000000000 AM. Am trying to get rows having the columns matching a specific date( ignoring the time values), my where looks like this
WHERE to_date(COMPLY_RUN_DASHBOARD_DATE,'DD-MON-RR')='" & Now.Date & "'"i get the following error :CheckError ORA-01830: date format picture ends before converting entire input string
how can I calculate the download speed if I use a webclient to download files async
View 2 RepliesI'm trying to write a 'developer friendly' wrapper for the Windows API EnumWindows - the problem is that the API uses a callback function that gets invoked on another thread, where as I want my wrapper function to simplify this and make it more useful by working like any other normal synchronous function and just returning a value.
Now if the API just called the callback once that would be fine, as I would just call the API and make the wrapper function wait until it got a signal from the callback function telling it to continue... but the API calls the callback function over 100 times (once for every window handle that exists). The biggest problem is that there is nothing that indicates that any particular call to this callback function is the last one, so my wrapper function has no idea when it is safe to continue and return the list of window handles to the caller.
The only solution I could think of is to do this:
1. The wrapper function calls the API and starts a timer that waits 2 seconds before it raises the Elapsed event. The wrapper function then pauses until it receives a signal (ManualResetEvent)
2. Each time the callback function is raised by the API on a different thread, it stops the timer (so this is before the 2 seconds have elapsed), adds the current window handle that was passed in by the API to the list of handles, then starts the timer again.
3. If the timer reaches its 2 second interval then it is assumed that we are at the end of the windows because otherwise the callback would have stopped the timer. So the timer's Elapsed event handler is what signals the original thread (that the wrapper function is executing on) to continue as we now have a complete list of windows to return.
This works fine and does exactly what I want... but I dont like it.
I dont like forcing the caller to wait an extra 2 seconds after the API has done its last callback but more importantly I dont like assuming that the API will never take longer than 2 seconds between callbacks. In reality on my PC it is never anywhere near that long between callbacks, it is something like 200 miliseconds, but I have no idea how long it would be on a slower PC and I want this to be completely reliable.
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I just put a button and a textbox on a form to try and learn to multi thread, i think i've done it correctly. but it still appears to freeze for a little bit just before it attempts to display the data. i think it's the invoking. Is it normal / have a done something wrong?
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I'm using .BeginConnect with an AsyncCallBack and for some odd reason when I try to add a string to a textbox using the sub below, from a routine within the socket, it just does not work. It's not stating an invoke is required either.Private Delegate Sub DelegateAddText(ByRef theText As String, ByRef AddReturn As Boolean, ByRef AddPrefix As Boolean) Public Sub AddText(ByRef theText As String, ByRef AddReturn As Boolean, ByRef AddPrefix As Boolean)
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as a side note which would be more efficient ... Indexing sockets and passing indexes through routines, or spawning classes. I realize spawning may use more memory but is it faster than indexing?
I have a while loop where it fetches record from csv and inserts to sql table. Now csv may contain many rows.What I want is if one row fails just log to a file and continue with next record.I was thinking of try and catch but that will exit the program.
while (csv.readnextline)
'assign csv columns to objects
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I'm making a small version of Spy++ and i would like to recreate the function that finds windows by dragging your mouse over it. Now that is pretty easy but one little annoyance is some windows minimize or loose focus ect when you bring the mouse pointer over them.
I would like to know if you can stop a program from gaining focus or minimizing. And i know i can get the handles of open windows by the EnumWindows function?
my program freezes untill the loading has finished.Is this normal? And if it is then how can I prevent my program from not allowing me to go back to the other form untill the loading has completed?I'm using this url as a start up page for my custom browser;so can I prevent my program from freezing or not ?It looks as if my custom browser form keeps demanding focu
View 5 RepliesIve been working recently on a chat. Ive been using FTP to comunicate through both forms but it need to constantly download the new data and make the application freeze. Even with a Backgroundworker. So my question is : is there a way to keep a constant connection between the form and the host? And not LAN ,I mean that doesnt need to be on the same router.
View 1 Repliesi got the function, but it only can get the outer html, any method or suggestion to get the innerhtml with webclient?
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How can I integrate a ProgressBar in this code? It takes normally some seconds (9-10), but my program looks like a "crash", for this reason i want use a ProgressBar
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I've just switched my code over that downloads data as bytes to use a WebClient. I add a header saying I will accept GZip and the site I'm downloading from sends me the data compressed. The problem is, how can I check to make sure it is compressed data before attempting to decompress it? It was much simpler when I was using a Web Request to check the response headers, but I'm having a little trouble checking the reponse headers with a WebClient. Does anybody out there accept compression with a WebClient?
View 1 RepliesI make a lot of programs that require an internet connection to download things from the web.At the very beginning, I used WebClient, as I didn't know Socket & how it worked.But now, I use Socket all the time, altough it's more lines of code. It seems to work faster then WebClient.I am interested if this is really true & why WebClient is slower (so is HttpWebRequest) then just a Socket.I've setup 2 threads which starts on the click of a button (WebClient thread starts first), the Socket beats the WebClient by just some milliseconds, but still.Each way has it's advantages & disadvantages, e.g.: if you use Socket, you need to write the header yourself & parse the response header.My question is, which one do you prefer & why ?Do you know why WebClient & HttpWebRequest are slower then Socket, as I assume, WebClient & HttpWebRequest both use tcp to download the things.
View 2 RepliesI am trying to download a 163 KB jpg file from the web with Webclient. The dimensions of it are ~332 x 491 pixels.
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I'm using the WebClient class' OpenWriteAsync function, and I'm having a little trouble with it. I want it to write some information to a .txt file I have uploaded on my FTP. I made it display a message after it has completed doing so, and the message does indeed pop up.However, I've checked my .txt file numerous times, and it hasn't actually been e Here's some of my
Dim otherclient As New WebClient()
AddHandler otherclient.OpenWriteCompleted, AddressOf WriteCompleted
otherclient.OpenWriteAsync(New Uri(URL))
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working in an intranet sit .downloadString took less than one second,but some times the server is down (maitenance or so on) and the the result took maybe one minute or so.Is there any way to set an lower interval?for example, if the server doesn't respond in 9 seconds return empty string, or so on.
I've read some about async comm but not sure what is the best solution.
I have the following HTML Form That I'm trying to automate:
<html>
<body>
<!-- The data encoding type, enctype, MUST be specified as below -->
<form enctype="multipart/form-data"
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I have been prototyping a simple site search tool.I found some online references to using webclient.download data. I have a (mostly) working prototype, but it only returns static HTML on the page that is being searched.I also would like to be able to search the contents of controls (such as text in label controls that are set at run time.) In the code below, the data in label1 is not returned.[code].....
View 3 RepliesI'm trying to download a simple text file from a web server. It's easily accessible from the web browser and I can download it from the web browser. However, whenever I use a WebClient to download the file, I get a 403 Access Forbidden Error! I'm not sure what I'm supposed to do. I haven't come across this kind of error in programming before and I'm not sure what I'm supposed to do to get around it.
View 2 RepliesI've managed to narrow down my issue to a simple annoyance. I had a Webbrowser control mostly coded to navigate around an Oracle CRM On Demand site to generate metric reports, but then realized when I tried to build in the auto-download part, that the Webbrowser object wasn't going to give me the behind-the-scenes control I wanted. Searching online, it seems the Webclient control might be a better route. However I'm stuck trying to get by the login page so I can use the Download-File method to get my generated xls report. [Code] But every reply from the server has "Sign In Error: Both a user sign in ID and a password must be given." which tells me the form/post data isn't getting where it needs to go (It thinks the form is blank at [Code].
The above username and password are bogus of course, but once I can get a different reply then 'the fields are blank' I can worry about correct logon information. I'm just not sure what I'm not doing correctly or if I need to include something else. Since it's a publicly accessible site and I'm stuck getting something in the form to be 'seen', it should be easy for others to try and test.
I am getting an error with this Dim Web As New WebClient Web.Proxy = "69.196.16.237:62159" It says runtime errors may occur when converting string to System.Net.IWebProxy What does that mean?
View 9 Replieshave any examples for UploadFileAsync? Including both server and client examples?
View 1 RepliesWhen I go to webcrawler.com and search for something, then look at the source code, a chunk of HTML similar to this displays the search results:
<div id="webResults">
<div class="searchResult webResult">
<a class="resultTitle" data-icl-coi="540" data-icl-cop="results-main" href=[website] target="_blank">[title]</a>
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But when I use WebClient.DownloadString to read the source code to a textbox, I only get this:
<div id="webResults">
</div>
There's nothing. All of the webresults have been removed.How come I can view the code in my internet browser but not on my application?? I even used an InStr method to confirm that the results weren't contained in the generated code.
I'm using loop to read data from sql and then make some calculations then save it again to another table but when application loop for 3 or 4 times it's freeze but the job is done but if loop = 10 or more then it is freeze and hangup for long time .i need to learn how to make my application working better and never freeze and make application working with any count for loop without freeze .
View 7 RepliesI have two methods on the page. One AddMessageToInboxOutbox(params[]) and other one SendNewMessageMail(params[]).
Once user sends an message to other other first message is added to DB and then sent to recipient's email. Sometimes SMTP is heavy loaded and it takes up to 5 seconds to get answer from it. I want to enclose SendNewMessageMail(params[]) with async call using other thread or something. I have never done that.
How do i perform this action right in ASP.NET?
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In my scenario the Button_Click is a command delegate in the VM, and the Thread.Sleep is some long-running process (about 2-10 seconds). I want, that when the user calls the command, it should immediately update the UI disabling the button so the user cannot execute it while it's running, then execute that operation, then, when operation completed, unblock the button.
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I have a dgv, I populate it, and I insert a row at the pos 0. And I want to freeze this row even when the user sorts the dgv.
How can I make this? The frozen property alone seems to be not enough.
Currently I have to retrieve over 2000 records from DB and bind with combobox. and then follow with another 3 retrieving (less than 20 records)
My problem is when I call this function, my GUI became freeze.
I try to use Application.DoEvents() method but it still didn't work.I read some post and pages, they mention about BackGroundWorker and .Net 2.0. But what i use it MS 2003 with 1.1 so i think i can't access BackGroundWorker.
I have a bunch of operations that need to be executed simultaneously. For this I'm using the thread pool to execute the tasks. I'd like to know if it's possible to consume some sort of Async Callback (similar to BackgroundWorker.DoWorkComplete) when each thread is finished. The reasoning behind this is that I have a windows service running that uses IPC to update a GUI and I need to know the time at which each specific thread finishes I've used background workers to do a set of tasks and they work perfectly, however, they take longer than I would like. I've timed the execution on my BGW method for a designated number of said tasks and it took 27 seconds, and the same set of tasks takes 4 seconds using the threadpool method. I've also tried using managed threads, to the same effect as the background workers.
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