Search Results

Search found 4681 results on 188 pages for 'handling'.

Page 49/188 | < Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >

  • Several client waiting for the same event

    - by ff8mania
    I'm developing a communication API to be used by a lot of generic clients to communicate with a proprietary system. This proprietary system exposes an API, and I use a particular classes to send and wait messages from this system: obviously the system alert me that a message is ready using an event. The event is named OnMessageArrived. My idea is to expose a simple SendSyncMessage(message) method that helps the user/client to simply send a message and the method returns the response. The client: using ( Communicator c = new Communicator() ) { response = c.SendSync(message); } The communicator class is done in this way: public class Communicator : IDisposable { // Proprietary system object ExternalSystem c; String currentRespone; Guid currentGUID; private readonly ManualResetEvent _manualResetEvent; private ManualResetEvent _manualResetEvent2; String systemName = "system"; String ServerName = "server"; public Communicator() { _manualResetEvent = new ManualResetEvent(false); //This methods are from the proprietary system API c = SystemInstance.CreateInstance(); c.Connect(systemName , ServerName); } private void ConnectionStarter( object data ) { c.OnMessageArrivedEvent += c_OnMessageArrivedEvent; _manualResetEvent.WaitOne(); c.OnMessageArrivedEvent-= c_OnMessageArrivedEvent; } public String SendSync( String Message ) { Thread _internalThread = new Thread(ConnectionStarter); _internalThread.Start(c); _manualResetEvent2 = new ManualResetEvent(false); String toRet; int messageID; currentGUID = Guid.NewGuid(); c.SendMessage(Message, "Request", currentGUID.ToString()); _manualResetEvent2.WaitOne(); toRet = currentRespone; return toRet; } void c_OnMessageArrivedEvent( int Id, string root, string guid, int TimeOut, out int ReturnCode ) { if ( !guid.Equals(currentGUID.ToString()) ) { _manualResetEvent2.Set(); ReturnCode = 0; return; } object newMessage; c.FetchMessage(Id, 7, out newMessage); currentRespone = newMessage.ToString(); ReturnCode = 0; _manualResetEvent2.Set(); } } I'm really noob in using waithandle, but my idea was to create an instance that sends the message and waits for an event. As soon as the event arrived, checks if the message is the one I expect (checking the unique guid), otherwise continues to wait for the next event. This because could be (and usually is in this way) a lot of clients working concurrently, and I want them to work parallel. As I implemented my stuff, at the moment if I run client 1, client 2 and client 3, client 2 starts sending message as soon as client 1 has finished, and client 3 as client 2 has finished: not what I'm trying to do. Can you help me to fix my code and get my target? Thanks!

    Read the article

  • Error debugging - Conversion from String to Double

    - by Jamie Taylor
    I'm doing some error debugging trying to get the errors on our website down to a minimum and there seems to be an error that is popping up quite a lot Conversion from string "" to type 'Double' is not valid. I'm unable to replicate this problem but I can see that it is happening. I've been looking through the code in one of the pages and strolled across this Dim varWeek As String If varWeek < 10 Then 'Do something' End If Could this be causing the problem as it is trying to see if a String is less than 10 which is an Integer? As I said before as I am unable to see this error in the first place so changing this to an Integer doesn't change anything on my system. Thanks.

    Read the article

  • How to roll back changes in gridview in case of incorrect input

    - by Mustafa A. Jabbar
    Hi, I have a DataGridView that is bound to a list of object. It has some columns that the user can edit. There are certain inputs that are not allowed for a row as a whole. How can I roll back if the user enters invalid inputs in some cell. I tried using the RowValidating event handler but it was not called after cell value has been changed. Even when I implemet CellValueChanged, I still cannot roll back the changes. Any idea how to accomplish this

    Read the article

  • I have an Errno 13 Permission denied with subprocess in python

    - by wDroter
    The line with the issue is ret=subprocess.call(shlex.split(cmd)) cmd = /usr/share/java -cp pig-hadoop-conf-Simpsons:lib/pig-0.8.1-cdh3u1-core.jar:lib/hadoop-core-0.20.2-cdh3u1.jar org.apache.pig.Main -param func=cat -param from =foo.txt -x mapreduce fsFunc.pig The error is. File "./run_pig.py", line 157, in process ret=subprocess.call(shlex.split(cmd)) File "/usr/lib/python2.7/subprocess.py", line 493, in call return Popen(*popenargs, **kwargs).wait() File "/usr/lib/python2.7/subprocess.py", line 679, in __init__ errread, errwrite) File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child raise child_exception OSError: [Errno 13] Permission denied Let me know if any more info is needed. Any help is appreciated. Thanks.

    Read the article

  • ASP.NET: How can I properly redirect requests with 404 errors?

    - by Adrian Grigore
    Hi, I'd like my ASP.NET MVC application to redirect failed requests to matching action methods of a certain controller. This works fine on my development machine running Windows 7, but not on my production machine running Windows 2008 R2. I set up my web.config as follows: <customErrors mode="On" defaultRedirect="/Error/ServerError/500"> <error statusCode="403" redirect="/Error/AccessDenied" /> <error statusCode="404" redirect="/Error/FileNotFound" /> </customErrors> This customErrors section works fine on both of my machines (production and development) for 500 Internal Server errors. It also works fine for 404 errors on my development machine. However, it does not properly redirect 404 errors on the production machine. Instead of /Error/FileNotFound, I get the standard 404 page that comes with IIS 7. What could be the problem here?

    Read the article

  • Are event handlers in JavaScript called in order?

    - by musicfreak
    I know this is a simple question, but I haven't had the chance to test it in any browser other than Firefox. If I attach multiple event handlers to a single event on a single DOM element, are the event handlers guaranteed to be called in the order they were added? Or should I not rely on this behavior?

    Read the article

  • Iterating through Event Log Entry Collection, IndexOutOutOfBoundsException

    - by fjdumont
    Hello, in a service application I am iterating through the Windows application event log to parse Events in order react depanding on the entry message. In the case that the event log is full (Windows usually makes sure there is enough space by deleting old entries - this is configurable in the eventvwr.exe settings), the service always runs into an IndexOutOfBoundsException while iterating through the EventLog.Entries collection. No matter how I iterate (for-loop, using the collections enumerator, copying the collection into an array, ...), I can't seem to get rid of this ´bug´. Currently, I ensure that the log is not full in order to keep the service running by regularly deleting the last few item by parsing the event log file and deleting the last few nodes (Don't beat me up, I couldn't find a better alternative...). How can I iterate through the collection without trying to access already deleted entries? Is there probably a more elegant method? I am only trying to acces the logs written during the last x seconds (even LINQ failed to select those when the log is full - same exception), could this help? Thanks for any advice and hints Frank Edit: I forgot to mention that my assumption is the loops are accessing entries which are being deleted during iteration by Windows. Basically that is why I tried to clone the collection. Is there perhaps a way to lock the collection for a small amount of time for just my application?

    Read the article

  • Communication between layers in an application

    - by Petar Minchev
    Hi guys! Let's assume we have the following method in the business layer. What's the best practice to tell the UI layer that something went wrong and give also the error message? Should the method return an empty String when it was OK, otherwise the error message, or should it throw another exception in the catch code wrapping the caught exception? If we choose the second variant then the UI should have another try,catch which is too much try,catch maybe. Here is a pseudocode for the first variant. public String updateSomething() { try { //Begin transaction here dataLayer.do1(); dataLayer.do2(); dataLayer.doN(); } catch(Exception exc) { //Rollback transaction code here return exc.message; } return ""; } Is this a good practice or should I throw another exception in the catch(then the method will be void)?

    Read the article

  • What should I do if a IOException is thrown?

    - by Roman
    I have the following 3 lines of the code: ServerSocket listeningSocket = new ServerSocket(earPort); Socket serverSideSocket = listeningSocket.accept(); BufferedReader in = new BufferedReader(new InputStreamReader(serverSideSocket.getInputStream())); The compiler complains about all of these 3 lines and its complain is the same for all 3 lines: unreported exception java.io.IOException; In more details, these exception are thrown by new ServerSocket, accept() and getInputStream(). I know I need to use try ... catch .... But for that I need to know what this exceptions mean in every particular case (how should I interpret them). When they happen? I mean, not in general, but in these 3 particular cases.

    Read the article

  • Why use event listeners over function calls?

    - by Organiccat
    I've been studying event listeners lately and I think I've finally gotten them down. Basically, they are functions that are called on another object's method. My question is, why create an event listener when calling the function will work just fine? Example, I want to call player.display_health(), and when this is fired, the method player.get_health() should be fired and stored so that display_health() has access to it. Why should I use an event listener over simply calling the function? Even if display_health() were in another object, this still doesn't appear to be a problem to me. If you have another example that fits the usage better, please let me know. Perhaps particular languages don't benefit from it as much? (Javascript, PHP, ASP?)

    Read the article

  • Handling auto-incrementing IDENTITY SQL Server fields with LINQ to SQL in C#

    - by Maxim Z.
    I'm building an ASP.NET MVC site that uses LINQ to SQL to connect to SQL Server, where I have a table that has an IDENTITY bigint primary key column that represents an ID. In one of my code methods, I need to create an object of that table to get its ID, which I will place into another object based on another table (FK-to-PK relationship). At what point is the IDENTITY column value generated and how can I obtain it from my code? Is the right approach to: Create the object that has the IDENTITY column Do an InsertOnSubmit() and SubmitChanges() to submit the object to the database table Get the value of the ID property of the object

    Read the article

  • How do I indicate that a class doesn't support certain operators?

    - by romeovs
    I'm writing a class that represents an ordinal scale, but has no logical zero-point (eg time). This scale should permit addition and substraction (operator+, operator+=, ...) but not multiplication. Yet, I always felt it to be a good practice that when one overloads one operator of a certain group (in this case the math operators), one should also overload all the others that belong to that group. In this case that would mean I should need to overload the multiplication and division operators also, because if a user can use A+B he would probable expect to be able the other operators. Is there a method that I can use to throw an error for this at compiler time? The easiest method would be just no to overload the operators operator*, ... yet it would seem appropriate to add a bit more explaination than operator* is not know for class "time". Or is this something that I really should not care about (RTFM user)?

    Read the article

  • Keyboard- and mouse-event transparent widget

    - by Gajender
    When i click a button my main window i want it to become transparent to keyboard and mouse events, i.e. all keyboard and mouse events should pass to any windows below it as if that window is not present there. "Qt::WA_TransparentForMouseEvents" does not work here as this only make child windows transparent to keyboard and mouse events i guess. And my window is main window and i want to pass all event to any window on desktop not just parent window.

    Read the article

  • Event handling for a dynamically added user control

    - by francisf
    Hi, I have a user control say SearchVendor.ascx which contains 4 buttons a gridview and another user control. I need to load the control dynamically actually as a modal pop up I get this code VendorProductSearch uc = Page.LoadControl("~/Controls/Proposal/VendorProductSearch.ascx") as VendorProductSearch; uc.ShowVendorProductSearch(true); _tempPlaceHolder.Controls.Add(uc); it works fine the control gets loaded properly but onclick of any button the second time the control disappears ??? I want the dynamically added control to remain until the user clicks on the cancel button Any idea as to how to achive this ? Thanks & Regards, Francis P.

    Read the article

  • Javascript handling textarea

    - by bbenton
    Hi all, I'm a bit new to Javascript and am trying to create a delimited string from a textare. The problem is when passing in the textarea, it adds newlines for each row on the textarea. I need to have the entire textarea parsed into a string with a delimiter for each line (replacing the newline char). So for example, if you passed in a textarea with the following lines (which is also how it looks when using the alert function): abcd efgh ijkl It would look like: abcd-efgh-ijkl after parsing. function submitToForm(form) { var param_textarea = form.listofplugins.value; var test = param_textarea.replace(/\\r?\\n/, /:/) alert(test); } Thanks a lot!

    Read the article

  • Manipulating a NSTextField via AppleScript

    - by Garry
    A little side project I'm working on is a digital life assistant, much like project JARVIS. What I'm trying to do is speak to my mac, have my words translated to text and then have the text interpreted by my program. Currently, my app is very simple, consisting of a single window containing a single wrapped NSTextView. Using MacSpeech Dictate, When I say the custom command "Jeeves", MacSpeech ensures that my app is frontmost, highlights any text in the TextField and clears it, then presses the Return key to trigger the textDidEndEditing method of NSTextField. This is done via Applescript. MacSpeech then switches to dictation mode and the next sentence I say will appear in the NSTextField. What I can't figure out is how to signify that I have finished saying a command to my program. I could simply say another keyword like "execute" or something similar that would send an AppleScript return keystroke to my app (thereby triggering the textDidEndEditing event) but this is cumbersome. Is there a notification that happens when text is pasted into a NSTextField? Would a timer work that would fire after maybe three seconds once my program becomes frontmost (three seconds should be sufficient for me to say a command)? Thanks,

    Read the article

  • Handling Session ID with Spring

    - by Max
    Hi, I'm trying to build a Spring server for GWT (you can think of it as of Javascript AJAX client). But I can't decide on one point of architecture. How should session be created and used? The obvious easiest way - is to use HTTP sessions (cookies and stuff). Looks fine, but I think that sending session ID separate from the headers would be better (SOAP style). So, what is better: getMyPetsName(String sessionID, int petID) or getMyPetsName(int petID) + session ID through HTTP header (cookies or something). Another question is, if I use the first way (which I like more) - how do I handle session in Spring? I'm really newbie in Spring, and googling did not help. What I mean is: String getMyPetsName(String sessionID, int petID) { Session s = someWayToGetItById(sessionID); } Thanks in advance.

    Read the article

  • Capture and handling the tab/Textchanged event in a textbox in asp.net MVC

    - by Icerman
    I have the following code th handle a user name validation on the server side. But the event seems not firing since break points in js or C# code didn't hit. Can anyone point out where I did wrong? Here is the user control which has a user name textbox: <%: Html.TextBox("UserName", Model.Username, new { maxlength = "40", size = "20", tabindex = "1", @onchange = "CheckAvailability()" })% CheckAvailability() is defined in the User.Validation.js and included in the above user control: $(document).ready(function () { function CheckAvailability() { $.post("/Home/Survey/CheckAvailability", { Username: $("#UserName").val() }, function (data) { var myObject = eval('(' + data + ')'); var newid = myObject; if (newid == 0) { $("#usernamelookupresult").html("<font color='green'>Available :-D</font>") } else { $("#usernamelookupresult").html("<font color='red'>Taken :-(</font>") } }); } }); Here is the survey controller function which will have server side validation: [HttpPost] public ActionResult CheckAvailability(string Username) { int Taken = 0; // This is where you add your database lookup if (Username == "abc") { Taken = 1; } return Json(Taken); }

    Read the article

  • Reverse massive text file in Java

    - by DanJanson
    What would be the best approach to reverse a large text file that is uploaded asynchronously to a servlet that reverses this file in a scalable and efficient way? text file can be massive (gigabytes long) can assume mulitple server/clustered environment to do this in a distributed manner. open source libraries are encouraged to consider I was thinking of using Java NIO to treat file as an array on disk (so that I don't have to treat the file as a string buffer in memory). Also, I am thinking of using MapReduce to break up the file and process it in separate machines. Any input is appreciated. Thanks. Daniel

    Read the article

  • Handling Application Logic in Multiple AsyncTask onPostExecute()s

    - by stormin986
    I have three simultaneous instances of an AsyncTask for download three files. When two particular ones finish, at the end of onPostExecute() I check a flag set by each, and if both are true, I call startActivity() for the next Activity. I am currently seeing the activity called twice, or something that resembles this type of behavior. Since the screen does that 'swipe left' kind of transition to the next activity, it sometimes does it twice (and when I hit back, it goes back to the same activity). It's obvious two versions of the activity that SHOULD only get called once are being put on the Activity stack. The only way I can find that this is possible is if both AsyncTasks' onPostExecute() executed SO simultaneously that they were virtually running the same lines at the same time, since I set the 'itemXdownloaded' flag to true right before I check for both and call startActivity(). But this is happening enough that it's very hard for me to believe that both downloads are finishing precisely at the same time and having their onPostExecute()s so close together... Any thoughts on what could be going on here? General gist of code (details removed, ignore any syntactical errors I may have edited in): // In onPostExecute() switch (downloadID) { case DL1: dl1complete = true; break; case DL2: dl2complete = true; break; case DL3: dl3complete = true; break; } // If 1 and 2 are done, move on (DL3 still going in background) if ( downloadID != DL3 && dl1complete && dl2complete) { ParentClass.this.startActivity(new Intent(ParentClass.this, NextActivity.class)); }

    Read the article

  • Server.TransferRequest returns blank page on specific server

    - by jishi
    I'm facing an issue that seems to be related to configuration. I have a webapplication based on MonoRail, where we utilize the routing feature from MonoRail. On the first request after the application has started, the routing isn't initialized. To circumvent this, I have the following code in Application_OnError(): public virtual void Application_OnError() { if ( // identified as routing error ) Server.TransferRequest( Context.Request.RawUrl, false ); return; } Problem beeing that on our development server (which runs server 2008 R2, with IIS 7.5 and .NET 3.5) returns a blank page without headers, but on my workstation (which runs win7, IIS 7.5 and .NET 3.5) it works fine. What could be the cause of this? If the code in Application_OnError() throws an exception, what would be the expected output? I have verified the following: The access-log shows one entry, I'm not sure if a TransferRequest would show up as a second entry when invoked successfully The application actually do some work according to my internal logs, and it doesn't die since a subsequent requests works flawlessly (because routing will be active) Any hints on what to look for would be greatly appreciated!

    Read the article

  • Using a general class for execution with try/catch/finally?

    - by antirysm
    I find myself having a lot of this in different methods in my code: try { runABunchOfMethods(); } catch (Exception ex) { logger.Log(ex); } What about creating this: public static class Executor { private static ILogger logger; public delegate void ExecuteThis(); static Executor() { // logger = ...GetLoggerFromIoC(); } public static void Execute(ExecuteThis executeThis) { try { executeThis(); } catch (Exception ex) { logger.Log(ex); } } } And just using it like this: private void RunSomething() { Method1(someClassVar); Method2(someOtherClassVar); } ... Executor.Execute(RunSomething); Are there any downsides to this approach? (You could add Executor-methods and delegates when you want a finally and use generics for the type of Exeception you want to catch...)

    Read the article

  • C++ visitor pattern handling templated string types?

    - by Steve the Plant
    I'm trying to use the visitor pattern to serialize the contents of objects. However one snag I'm hitting is when I'm visiting strings. My strings are of a templated type, similar to STL's basic_string. So something like: basic_string<char_type, memory_allocator, other_possible_stuff> \\ many variations possible! Since I can have very many different templated string types, I can't go and add them to my visitor interface. It would be ridiculous. But I can't add templates to my VisitString method because C++ prevents using templates parameters in virtual methods. So what are my options to work around this?

    Read the article

< Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >