Search Results

Search found 11639 results on 466 pages for 'numerical methods'.

Page 312/466 | < Previous Page | 308 309 310 311 312 313 314 315 316 317 318 319  | Next Page >

  • What's causing "Unable to retrieve native address from ByteBuffer object"?

    - by r0u1i
    As a very novice Java programmer, I probably should not mess with that kind of things. Unfortunately, I'm using a library which have a method that accepts a ByteBuffer object and throws when I try to use it: Exception in thread "main" java.lang.NullPointerException: Unable to retrieve native address from ByteBuffer object Is it because I'm not using a non-direct buffer? edit: There's not a lot of my code there. The library I'm using is jNetPcap, and I'm trying to dump a packet to file. My code takes an existing packet, and extract a ByteBuffer out of it: byte[] bytes = m_packet.getByteArray(0, m_packet.size()); ByteBuffer buffer = ByteBuffer.wrap(bytes); Then it calls on of the dump methods of jNetPcap that takes a ByteBuffer.

    Read the article

  • asynchronous calls in asp.net

    - by lockedscope
    in this sample, two threads created; a worker thread created by BeginInvoke and an I/O completion thread created by SendAsync method. but another author in his UnsafeQueueNativeOverlapped example, don't recommend this. i want to use SendAsync or ...Async in an asp.net page and i want to use PageAsyncTask. however, its BeginEventHandler requires AsyncResult to be returned which SendAsync does not return. afaik, event based async pattern is the most recommended way so how could we call SendAsync or any ...Async methods without creating two threads and hurting the performance?

    Read the article

  • Security for web services only used from a Silverlight application?

    - by Lasse V. Karlsen
    I have googled a bit for how I should handle security in a web service application when the application is basically the data repository for a Silverlight application, but have gotten inconclusive results. The Silverlight application is not supposed to have its own user authentication, since it will be reachable only through a web application that the user have already authenticated to get into. As such, I was thinking I could simply add a parameter to the SL application that is a cookie-type value, with a certain lifetime, linked to the user in the database. The SL application would then have to pass this value alongside other parameters to the web services. Since the web service is hopefully going to be a generic web service endpoint, few methods, adding an extra parameter at this level will not be a problem. But, am I supposed to roll this system on my own? It sounds to me as this isn't exactly new features that nobody has considered before, so what are my options?

    Read the article

  • Can Gitosis enforce correct user name/email?

    - by koumes21
    Gitosis is able to authenticate users based on public/private key pair. It is able to find out which user is currently committing. However, the user name and email is taken from the client's Git configuration ('git config user.name' etc.), which can be set to arbitrary values. Is there any way to associate user names and emails with their public keys and then make Gitosis uses these names and emails as the name and email of the committer? I do not care if I will use Gitosis or WebDAV or some other alternative to share the repository. It just seems to me that none of the available methods supports this enforcement of using some kind of "correct" user name and email. If there exists some alternative, please tell me about it.

    Read the article

  • How does one refer to the game1 class's variables in XNA

    - by user1149068
    I try to refer to an array in the Game1 class by creating an object of the Game1 class with its definition Game1 gameObject; , its declaration gameObject = new Game1(); in the constructor, and its usage gameObject.tileArray[xInt, yInt].treed = true;. The game1 class itself remains unchanged in its class code other than some methods and variables. When I try to use this code in the TreeRegion class it gives me "Object reference not set to an instance of an object," leading me to believe that the game1 class is null somehow. How might one change the class or object in order to refer to game1's variables? Mind you I am self-taught and still rather new to C#. The class that refers to game1: http://pastebin.com/0chEcKfq Game1 itself http://pastebin.com/zLDVzCca

    Read the article

  • How to detect tab key pressing in C#?

    - by user342325
    I want to detect when tab key is pressed in a textBox and focus the next textbox in the panel. I have tried out keyPressed method and keyDown method. But when I run the program and debug those methods are not calling when the tab key is pressed. Here is my code. private void textBoxName_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Tab) { textBoxUsername.Focus(); } } private void textBoxName_KeyPress(object sender, KeyPressEventArgs e) { if (e.KeyChar==(char)Keys.Tab) { textBoxUsername.Focus(); } } Please correct me.Thank you.

    Read the article

  • What is the time taken by java to call a method in another package?

    - by satish
    I have an assignment where i need to do feasibility study on two of my approaches and find optimized one. There are two packages A and B User input is gathered in A and then sent to B for execution. Now my approaches are 1. Call B methods from package A one by one. 2. Create a common method in B and send all the input as parameters. Which is feasible and best one, I know 2 is good in terms of code optimization and less number of calls. But, I want to understand what will be the execution time difference in above approaches How much time does java take to call method in another package? Is there any default value like x nano seconds or y milli seconds. Based on the time taken I can choose the appropiate one. Thanks

    Read the article

  • Deserialising Json to derived types in Asp.Net Web API

    - by IoChaos
    I'm calling a method of my WebAPI sending a json that I would like to match (or bind) with a model. In the controller I have a method like: public Result Post([ModelBinder(typeof(CustomModelBinder))]MyClass model); 'MyClass', wich is given as a parameter is an abstract class. I would like that at, depending of the type of json passed, the correct inherited class is instantiated. To achieve it, I'm trying to implement a custom binder. The problem is that (I don't know if it's very basic but I can't find anything) I don't know how to retrieve the raw Json (or better, some kind of serialization) that comes in the request. I see: actionContext.Request.Content But all methods are exposed as async. I don't know who this fits with passing the generate model to the controller method... Thanks a lot!

    Read the article

  • How do I catch the exception in windows application in c#?

    - by user291169
    Where should we catch exception • In Layer Boundary (UI-BLL & BLL-DAL) • In that methods where there is no interaction between Layers only some business logic present How do I write exception in Save/Delete where some DML statement executing? • What should I write in DAL end? • What should I write in BLL end? • What should I write in UI end? In Get/Load method How do we handle exception • What should I write in BLL end? • What should I write in UI end? Should I catch System exception?

    Read the article

  • Javascript 'class' and singleton problems

    - by Kucebe
    I have a singleton object that use another object (not singleton), to require some info to server: var singleton = (function(){ /*_private properties*/ var myRequestManager = new RequestManager(params, //callbacks function(){ previewRender(response); }, function(){ previewError(); } ); /*_public methods*/ return{ /*make a request*/ previewRequest: function(request){ myRequestManager.require(request); //err:myRequestManager.require is not a func }, previewRender: function(response){ //do something }, previewError: function(){ //manage error } }; }()); This is the 'class' that make the request to the server function RequestManager(params, success, error){ //create an ajax manager this.param = params; this._success = success; //callbacks this._error = error; } RequestManager.prototype = { require: function(text){ //make an ajax request }, otherFunc: function(){ //do other things } } The problem is that i can't call myRequestManager.require from inside singleton object. Firebug consolle says: "myRequestManager.require is not a function", but i don't understand where the problem is. Is there a better solution for implement this situation?

    Read the article

  • Using scanf() in C++ programs is faster than using cin ?

    - by zeroDivisible
    Hello, I don't know if this is true, but when I was reading FAQ on one of the problem providing sites, I found something, that poke my attention: Check your input/output methods. In C++, using cin and cout is too slow. Use these, and you will guarantee not being able to solve any problem with a decent amount of input or output. Use printf and scanf instead. Can someone please clarify this? Is really using scanf() in C++ programs faster than using cin something ? If yes, that is it a good practice to use it in C++ programs? I thought that it was C specific, though I am just learning C++...

    Read the article

  • How can I add an event handler to an event by name?

    - by cyclotis04
    I'm attempting to add an event handler for every control on my form. The form is a simple info box which pops up, and clicking anywhere on it does the same thing (sort of like Outlook's email notifier.) To do this, I've written a recursive method to add a MouseClick handler to each control, as follows: private void AddMouseClickHandler(Control control, MouseEventHandler handler) { control.MouseClick += handler; foreach (Control subControl in control.Controls) AddMouseClickHandler(subControl, handler); } However, if I wanted to add a handler for all of the MouseDown and MouseUp events, I'd have to write two more methods. I'm sure there's a way around this, but I can't find it. I want a method like: private void AddRecursiveHandler(Control control, Event event, EventHandler handler) { control.event += handler; foreach (Control subControl in control.Controls) AddRecursiveHandler(subControl, event, handler); }

    Read the article

  • Migrating Data to MSSQL 2008

    - by Fred Clown
    I am trying to migrate data from an Informix database to MSSQL 2008. I've got quite a lot of data to move. I've been try multiple methods to get the data over, and so far SQLBulkCopy in multiple chunks seems to be the fastest that I can find. Does anyone know of a faster means of getting the data over? I'm trying to cut down on the transfer time so that on my cut-over date I don't run out of time to do the full cut-over. Thanks.

    Read the article

  • Java - understanding servlets

    - by Trup
    I am working on a homework project that should implement a board game between 2 clients over an HttpServlet. I have couple of questions: 1) I read that HttpServlets must be stateless, however, for the sake of the game, I have to keep a lot of state(whose turn it is, the state of the board, etc). Do I have to keep this in the clients? Does the HttpServlet indeed have to be stateless, i.e. have no fields that track state? 2) I know that the clients will talk to the servlet via the doGet/doPost methods, but how can the servlet talk to the clients(for example, if player 1 just made a move and sent it to the servlet, the servlet has to tell client 2 what the move was). Thank you Also, if you can point me to a useful, simple example of a similar code online, I would be very grateful

    Read the article

  • RoR model field without validators, has*, delegates, etc

    - by jackr
    How can I declare a field, in the Rails model, when it doesn't have any "has_" relations, or validations, or delegations? I just need to ensure its existence and column width in the schema. Currently, I have no mention of the field in the "schema section" of the model file, but it's referenced in various methods that use it, and this seems to work. However, depending on my exact creation workflow, the underlying database table may be created as t.binary "field_name", :limit => 32 or t.binary "field_name", :limit => 255 This is not a restriction on the value (any binary value is valid, even NULL), only on the table column declaration. As it happens, 32 is enough -- it never receives any larger value, it's only ever written to like this: self.field_name = SecureRandom.random_bytes(32)

    Read the article

  • Magento and unsetting a custom boolean attribute

    - by Spongeboy
    Hi, I've added an attribute to a customer address entity. Attribute setup code is as follows- 'entity_type_id'=>$customer_address_type_id, 'attribute_code'=>'signature_required', 'backend_type'=>'int', 'frontend_input'=>'boolean', 'frontend_label' => 'Signature required', 'is_global' => '1', 'is_visible' => '1', 'is_required' => '0', 'is_user_defined' => '0', I have then - added attribute to model\entity\setup.php added a HTML field on the edit form I am now getting the attribute saved to the database when the checkbox is checked. However, it is not being unset when checkbox is unchecked (I'm guessing due to checkbox input not being 'post'-ed if unchecked. What is the best way to uncheck this? Should I add a default value of 0? Or unset/delete the attribute before save in the controller? Should I add get/set methods to the model?

    Read the article

  • gwt - Using List<Serializable> in a RPC call?

    - by Garagos
    I have a RPC service with the following method: public List<Serializable> myMethod(TransactionCall call) {...} But I get a warning when this method is analyzed, and then the rpc call fails Analyzing 'my.project.package.myService' for serializable types Analyzing methods: public abstract java.util.List<java.io.Serializable> myMethod(my.project.package.TransactionCall call) Return type: java.util.List<java.io.Serializable> [...] java.io.Serializable Verifying instantiability (!) Checking all subtypes of Object wich qualify for serialization It seems I can't use Serializable for my List... I could use my own interface instead (something like AsyncDataInterface, wich implements the Serializable interface) but the fact is that my method will return a list custom objects AND basic objects (such as Strings, int....). So my questions are: Is it a standart behaviour? (I can't figure out why I can't use this interface in that case) Does anyone have a workaround for that kind of situation?

    Read the article

  • Giving proper credit to a projects contributors

    - by Greg B
    I've recently been working with an opensource library for a commercial product. The opensource code is distributed from the website of the company who sells the proprietary product as a zip file. The library is a (direct) port to C# of the original library which is in Java. As such, it uses methods instead of getter/setter properties. The code contains copyright notices to the supplier of the product. The C# port was originally provided to the company by a 3rd party individual. I have modified the source to be more C# like and added a couple of small features. I want to put my version of the code out there (Google code or where ever) so that C# users of the software can benefit from a more native feeling library. How can I and/or how should I amend the copyright notice to give proper credit to The comercial owner of the original source The guy who provided the original C# port Myself and anyone else who contributes to the project in the future The source is provided under the LGPL V2.1,

    Read the article

  • What are the other new features of C# 4.0, after dynamic and optional parameters?

    - by Abel
    So, C# 4.0 came out yesterday. It introduced the much-debated dynamic keyword, named and optional parameters. Smaller improvements were the implicit ref and recognizing of indexed and default properties on COM methods, contra- and co-variance (really a .NET CLR feature, not C# only) and... Is that really it? Are dynamic and optional/named params the only real improvements to C#? Or did I miss something? Not that I'm complaining, but it seems a bit meager after C# 2.0 (generics) and C# 3.0 (lambda, LINQ). Maybe the language just reached actual maturity?

    Read the article

  • biginteger calculation problem

    - by murali
    I am using the following code but the parameters are not passed to the methods. BigInteger p = BigInteger.valueOf(0); BigInteger u1 = obj.bigi_calc(g1, l); In this g1,l are long values. The method is private BigInteger bigi_calc(long g1, long l){ BigInteger cal = BigInteger.valueOf(g1); BigInteger cal1= BigInteger.valueOf(l); for(BigInteger f = BigInteger.ONE;f.compareTo(cal1)>0;f=f.add(BigInteger.ONE)){ //BigInteger p= BigInteger.valueOf(0); p = cal.multiply(cal1); System.out.println("check p"+p); } // System.out.println("check p"+p); return p; } The elipse shows that it may be out of sync, but the parameters are not passed to the functions. Can you please help me to solve this problem?

    Read the article

  • Using Linq to SQL change events with attribute-based mapping

    - by R Mene
    I'm writing a new ASP.NET MVC2 application using Linq to SQL. This application depends on an existing SQL database. I am using attribute-based mapping to map my database fields to my Linq to SQL entities. I also need to make use of Linq to SQL's On[Property]Changed methods so I can perform change-auditing of database tables within my application. Whereas the documentation explains how to do this when using Linq to SQL's ORM and dbml files (i.e. by writing partial classes), it is not clear how to do with when using attribute-based mapping or when using XML-based mapping. It would be very helpful if someone could describe how to do this.

    Read the article

  • Tracing all events in VB.NET

    - by MatsT
    I keep running into situations where I don't know what event I have to listen to in order to execute my code at the correct time. Is there any way to get a log of all events that is raised? Any way to filter that log based on what object raised the event? EDIT: Final solution: Private Sub WireAllEvents(ByVal obj As Object) Dim parameterTypes() As Type = {GetType(System.Object), GetType(System.EventArgs)} Dim Events = obj.GetType().GetEvents() For Each ev In Events Dim handler As New DynamicMethod("", Nothing, parameterTypes, GetType(main)) Dim ilgen As ILGenerator = handler.GetILGenerator() ilgen.EmitWriteLine("Event Name: " + ev.Name) ilgen.Emit(OpCodes.Ret) ev.AddEventHandler(obj, handler.CreateDelegate(ev.EventHandlerType)) Next End Sub And yes, I know this is not a good solution when you actually want to do real stuff that triggers off the events. There are good reasons for the 1 method - 1 event approach, but this is still useful when trying to figure out which of the methods you want to add your handlers to.

    Read the article

  • Is select() Ok to implement single socket read/write timeout ?

    - by chmike
    I have an application processing network communication with blocking calls. Each thread manages a single connection. I've added a timeout on the read and write operation by using select prior to read or write on the socket. Select is known to be inefficient when dealing with large number of sockets. But is it ok, in term of performance to use it with a single socket or are there more efficient methods to add timeout support on single sockets calls ? The benefit of select is to be portable.

    Read the article

  • What is the MVC version of this code?

    - by Ian Boyd
    i'm trying to wrap my head around how to enterprise up my code: taking a simple routine and splitting it up into 5 or 6 methods in 3 or 4 classes. i quickly came up three simple examples of code how i currently write it. Could someone please convert these into an MVC/MVP obfuscated version? Example 1: The last name is mandatory. Color the text box red if nothing is entered. Color it green if stuff is entered: private void txtLastname_TextChanged(object sender, EventArgs e) { //Lastname mandatory. //Color pinkish if nothing entered. Greenish if entered. if (txtLastname.Text.Trim() == "") { //Lastname is required, color pinkish txtLastname.BackColor = ControlBad; } else { //Lastname entered, remove the coloring txtLastname.BackColor = ControlGood; } } Example 2: The first name is optional, but try to get it. We'll add a bluish tint to this "try to get" field: private void txtFirstname_TextChanged(object sender, EventArgs e) { //Firstname can be blank. //Hint them that they should *try* to get it with a bluish color. //If they do enter stuff: it better be not all spaces. if (txtFirstname.Text == "") { //Nothing there, hint it blue txtFirstname.BackColor = ControlRequired; } else if (txtFirstname.Text.Trim() == "") { //They entered spaces - bad user! txtFirstname.BackColor = ControlBad; } else { //Entered stuff, remove coloring txtFirstname.BackColor = SystemColors.Window; } } Example 3 The age is totally optional. If an age is entered, it better be valid: private void txtAge_TextChanged(object sender, EventArgs e) { //Age is optional, but if entered it better be valid int nAge = 0; if (Int32.TryParse(txtAge.Text, out nAge)) { //Valid integer entered if (nAge < 0) { //Negative age? i don't think so txtAge.BackColor = ControlBad; } else { //Valid age entered, remove coloring txtAge.BackColor = SystemColors.Window; } } else { //Whatever is in there: it's *not* a valid integer, if (txtAge.Text == "") { //Blank is okay txtAge.BackColor = SystemColors.Window; } else { //Not a valid age, bad user txtAge.BackColor = ControlBad; } } } Every time i see MVC code, it looks almost like random splitting of code into different methods, classes, and files. i've not been able to determine a reason or pattern to their madness. Without any understanding of they why it's being one some way, it makes no sense. And using the words model, view, controller and presenter, like i'm supposed to know what that means, doesn't help. The model is your data. The view shows data on screen. The controller is used to carry out the users actions And oranges taste orangy. Here's my attempt at splitting things up in order to make the code more difficult to follow. Is this anywhere close to MVC? private void txtFirstname_TextChanged(object sender, EventArgs e) { FirstnameTextChangedHandler(sender, e); } private void FirstnameTextChangedHandler(sender, e) { string firstname = GetFirstname(); Color firstnameTextBoxColor = GetFirstnameTextBoxColor(firstname); SetFirstNameTextBoxColor(firstnameTextBoxColor); } private string GetFirstname() { return txtFirstname.Text; } private Color GetFirstnameTextBoxColor(string firstname) { //Firstname can be blank. //Hint them that they should *try* to get it with a bluish color. //If they do enter stuff: it better be not all spaces. if (firstname == "") { //Nothing there, hint it blue return GetControlRequiredColor(); } else if (firstname.Trim() == "") { //They entered spaces - bad user! return GetControlBadColor(); } else { //Entered stuff, remove coloring return GetControlDefaultColor(); } } private Color GetControlRequiredColor() { return ControlRequired; } private Color GetControlBadColor() { return ControlBad; } private Color GetControlGoodColor() { return ControlGood; } //am i doin it rite i've obfuscated the code, but it's still altogether. The next step in the MVC obfuscation, i gather, is to hide the code in 3 or 4 different files. It's that next step that i don't understand. What is the logical separation of which functions are moved into what other classes? Can someone translate my 3 simple examples above into full fledged MVC obfuscation? Edit: Not ASP/ASP.NET/Online. Pretend it's on a desktop, handheld, surface, kiosk. And pretend it's language agnostic.

    Read the article

  • class method as hash value

    - by demas
    I have this working code: class Server def handle(&block) @block = block end def do @block.call end end class Client def initialize @server = Server.new @server.handle { action } end def action puts "some" end def call_server @server.do end end client = Client.new client.call_server My Server will handle more then one action so I want to change code such way: class Server def handle(options) @block = options[:on_filter] end def do @block.call end end class Client def initialize @server = Server.new my_hash = { :on_filter => action } @server.handle(my_hash) end def action puts "some" end def call_server @server.do end end client = Client.new client.call_server It is incorrect code because action() method calls on create my_hash, but if I try to modify code to: my_hash = { :on_filter => { action } } i get error message. Is it possible to create hash with methods as hash values ?

    Read the article

< Previous Page | 308 309 310 311 312 313 314 315 316 317 318 319  | Next Page >