Search Results

Search found 24726 results on 990 pages for 'message passing'.

Page 542/990 | < Previous Page | 538 539 540 541 542 543 544 545 546 547 548 549  | Next Page >

• Is MarshalByRefObject special?

  - by Vilx-

  .NET has a thing called remoting where you can pass objects around between separate appdomains or even physical machines. I don't fully understand how the magic is done, hence this question. In remoting there are two base ways of passing objects around - either they can be serialized (converted to a bunch of bytes and the rebuilt at the other end) or they can inherit from MarshalByRefObject, in which case .NET makes some transparent proxies and all method calls are forwarded back to the original instance. This is pretty cool and works like magic. And I don't like magic in programming. Looking at the MarshalByRefObject with the Reflector I don't see anything that would set it apart from any other typical object. Not even a weird internal attribute or anything. So how is the whole transparent proxy thing organized? Can I make such a mechanism myself? Can I make an alternate MyMarshalByRefObject which would not inherit from MarshalByRefObject but would still act the same? Or is MarshalByRefObject receiving some special treatment by the .NET engine itself and the whole remoting feat is non-duplicatable by mere mortals?

  Read the article

• static variable lose its value

  - by user542719

  I have helper class with this static variable that is used for passing data between two classes. public class Helper{ public static String paramDriveMod;//this is the static variable in first calss } this variable is used in following second class mathod public void USB_HandleMessage(char []USB_RXBuffer){ int type=USB_RXBuffer[2]; MESSAGES ms=MESSAGES.values()[type]; switch(ms) { case READ_PARAMETER_VALUE: // read parameter values switch(prm){ case PARAMETER_DRIVE_MODE: // paramet drive mode Helper.paramDriveMod =(Integer.toString(((USB_RXBuffer[4]<< 8)&0xff00))); System.out.println(Helper.paramDriveMod+"drive mode is selectd ");//here it shows the value that I need. ..........}}//let say end switch and method and the following is an third class method use the above class method public void buttonSwitch(int value) throws InterruptedException{ boolean bool=true; int c=0; int delay=(int) Math.random(); while(bool){ int param=3; PARAMETERS prm=PARAMETERS.values()[param]; switch(value){ case 0: value=1; while(c<5){ Thread.sleep(delay); protocol.onSending(3,prm.PARAMETER_DRIVE_MODE.ordinal(),dataToRead,dataToRead.length);//read drive mode System.out.println(Helper.paramDriveMod+" drive mode is ..........in wile loop");//here it shows null value }}//let say end switch and method what is the reason that this variable lose its value?

  Read the article

• How do I keep users from spoofing data through a form?

  - by Jonathan

  I have a site which has been running for some time now that uses a great deal of user input to build the site. Naturally there are dozens of forms on the site. When building the site, I often used hidden form fields to pass data back to the server so that I know which record to update. an example might be: <input type="hidden" name="id" value="132" /> <input type="text" name="total_price" value="15.02" /> When the form is submitted, these values get passed to the server and I update the records based on the data passed (i.e. the price of record 132 would get changed to 15.02). I recently found out that you can change the attributes and values via something as simple as firebug. So...I open firebug and change the id value to "155" and the price value to "0.00" and then submit the form. Viola! I view product number 155 on the site and it now says that it's $0.00. This concerns me. How can I know which record to update without either a query string (easily modified) or a hidden input element passing the id to the server? And if there's no better way (I've seen literally thousands of websites that pass the data this way), then how would I make it so that if a user changes these values, the data on the server side is not executed (or something similar to solve the issue)? I've thought about encrypting the id and then decrypting it on the other side, but that still doesn't protect me from someone changing it and just happening to get something that matches another id in the database. I've also thought about cookies, but I've heard that those can be manipulated as well. Any ideas? This seems like a HUGE security risk to me.

  Read the article

• jquery dialog is clearing my form fields and I need to return a value from a jquery dialog

  - by Seth

  1.) I have a jQuery dialog that is opened whenever a particular textbox is focused. The dialog's contents are loaded from ajax and the unique ID of the textbox that was focused is passed in the ajax call (like this): $('[name=start_airport[]],[name=finish_airport[]]').click(function(){   var id = $(this).attr('id');   if($('#use_advanced_airport_selector').attr('checked')) {     $('#advanced_airport_selector').dialog({       open : function() {         $(this).load('/flight-booker/advanced-airport-selector.php?callerID='+id);       }     });     $('#advanced_airport_selector').dialog('open');   } }); (where advanced_airport_selector is an empty div) THAT PART WORKS FINE. However, when I make my ajax call within my dialog, all my form values are reset! No matter what I do, when that dialog opens, all form values are reset (not just the value of the textbox that was focused). I simply don't understand what would cause this behavior! But that's only issue #1. 2.) I need to be able to return a value from that dialog box. I am passing the ID in the ajax query so that I can use a jquery selector to update the caller's value after certain actions are performed within the dialog box. However, I can't actually access that textbox because of DOM_ERRORS that I've never come across. It doesn't make any sense! There's way to much code to post, and it's really hard to explain, so sorry if I'm unclear as to what I'm asking.

  Read the article

• Java reflection appropriateness

  - by jsn

  This may be a fairly subjective question, but maybe not. My application contains a bunch of forms that are displayed to the user at different times. Each form is a class of its own. Typically the user clicks a button, which launches a new form. I have a convenience function that builds these buttons, you call it like this: buildButton( "button text", new SelectionAdapter() { @Override public void widgetSelected( SelectionEvent e ) { showForm( new TasksForm( args... ) ); } } ); I do this dozens of times, and it's really cumbersome having to make a SelectionAdapter every time. Really all I need for the button to know is what class to instantiate when it's clicked and what arguments to give the constructor, so I built a function that I call like this instead: buildButton( "button text", TasksForm.class, args... ); Where args is an arbitrary list of objects that you could use to instantiate TasksForm normally. It uses reflection to get a constructor from the class, match the argument list, and build an instance when it needs to. Most of the time I don't have to pass any arguments to the constructor at all. The downside is obviously that if I'm passing a bad set of arguments, it can't detect that at compilation time, so if it fails, a dialog is displayed at runtime. But it won't normally fail, and it'll be easy to debug if it does. I think this is much cleaner because I come from languages where the use of function and class literals is pretty common. But if you're a normal Java programmer, would seeing this freak you out, or would you appreciate not having to scan a zillion SelectionAdapters?

  Read the article

• Best Practice for Summary Footer (and the like) in MVC

  - by benpage

  Simple question on best practice. Say I have: public class Product { public string Name { get; set; } public string Price { get; set; } public int CategoryID { get; set; } public bool IsAvailable { get; set; } } and i have a view using IEnumerable< Product as the model, and i iterate through the Products on the page and want to show the total of the prices at the end of the list, should I use: <%= Model.Sum(x=> x.Price) %> or should I use some other method? This may extend to include more involved things like: <%= Model.Where(x=> x.CategoryID == 5 && x.IsAvailable).Sum(x=> x.Price) %> and even <% foreach (Product p in Model.Where(x=> x.IsAvailable) {%> -- insert html -- <% } %> <% foreach (Product p in Model.Where(x=> !x.IsAvailable) {%> -- insert html -- <% } %> I guess this comes down to should I have that sort of code within my view, or should i be passing it to my view in ViewData? Or perhaps some other way?

  Read the article

• Is this overly clever or unsafe?

  - by Liberalkid

  I was working on some code recently and decided to work on my operator overloading in c++, because I've never really implemented it before. So I overloaded the comparison operators for my matrix class using a compare function that returned 0 if LHS was less than RHS, 1 if LHS was greater than RHS and 2 if they were equal. Then I exploited the properties of logical not in c++ on integers, to get all of my compares in one line: inline bool Matrix::operator<(Matrix &RHS){ return ! (compare(*this,RHS)); } inline bool Matrix::operator>(Matrix &RHS){ return ! (compare((*this),RHS)-1); } inline bool Matrix::operator>=(Matrix &RHS){ return compare((*this),RHS); } inline bool Matrix::operator<=(Matrix &RHS){ return compare((*this),RHS)-1; } inline bool Matrix::operator!=(Matrix &RHS){ return compare((*this),RHS)-2; } inline bool Matrix::operator==(Matrix &RHS){ return !(compare((*this),RHS)-2); } Obviously I should be passing RHS as a const, I'm just probably not going to use this matrix class again and I didn't feel like writing another function that wasn't a reference to get the array index values solely for the comparator operation.

  Read the article

• What to pass parameters to start an workflow through WCF

  - by Rubens Farias

  It's possible to define some start values to an workflow using WorkflowInstance.CreateWorkflow, like this: using(WorkflowRuntime runtime = new WorkflowRuntime()) { Dictionary<string, object> parameters = new Dictionary<string, object>(); parameters.Add("First", "something"); parameters.Add("Second", 42); WorkflowInstance instance = runtime.CreateWorkflow(typeof(MyStateMachineWorkflow), parameters); instance.Start(); waitHandle.WaitOne(); } This way, a MyStateMachineWorkflow instance is created and First and Second public properties gets that dictionary values. But I'm using WCF; so far, I managed to create a Start method which accepts that two arguments and I set that required fields by using bind on my ReceiveActivity: using (WorkflowServiceHost host = new WorkflowServiceHost(typeof(MyStateMachineWorkflow))) { host.Open(); ChannelFactory<IMyStateMachineWorkflow> factory = new ChannelFactory<IMyStateMachineWorkflow>("MyStateMachineWorkflow"); IMyStateMachineWorkflow proxy = factory.CreateChannel(); // set this values through binding on my ReceiveActivity proxy.Start("something", 42); } While this works, that create an anomaly: that method should be called only and exactly once. How can I start an workflow instance through WCF passing those arguments? On my tests, I just actually interact with my workflow through wire after I call that proxy method. Is there other way?

  Read the article

• ASP.NET MVC (VB) error when publishing to test server

  - by Colin

  I have an ASP.NET MVC project that works fine on my local machine (no build errors, server errors or anything). However, when I publish the project to a test server, I get an "Object reference not set to an instance of an object" error on a For Each I have in my view. I have a function within a model that returns a DataRowCollection. I'm calling that function in my controller and passing the DataRowCollection to my View, which then iterates over the rows and displays the necessary information: In the Controller I have: Function Index() As ActionResult Dim MyModel As New Model ViewData("MyDataRowCollection") = MyModel.GetDataRowCollection() Return View() End Function And then in the View, which is throwing the error: <%@ Page Language="VB" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %> <asp:Content ID="indexTitle" ContentPlaceHolderID="TitleContent" runat="server"> My Page Title </asp:Content> <asp:Content ID="indexContent" ContentPlaceHolderID="MainContent" runat="server"> <% For Each MyDataRow In ViewData("MyDataRowCollection") ' do stuff with each MyDataRow Next %> I'm pretty new to ASP.NET MVC so I'm sure there might be a better way to do what I'm doing (I'd be happy to hear if there is), but my main concern is why this works fine on my local machine but throws an error on the For Each on the test server? Please let me know if I can clarify any of the above, and thanks in advance for any information.

  Read the article

• C++ CRTP(template pattern) question

  - by aaa

  following piece of code does not compile, the problem is in T::rank not be inaccessible (I think) or uninitialized in parent template. Can you tell me exactly what the problem is? is passing rank explicitly the only way? or is there a way to query tensor class directly? Thank you #include <boost/utility/enable_if.hpp> template<class T, // size_t N, class enable = void> struct tensor_operator; // template<class T, size_t N> template<class T> struct tensor_operator<T, typename boost::enable_if_c< T::rank == 4>::type > { tensor_operator(T &tensor) : tensor_(tensor) {} T& operator()(int i,int j,int k,int l) { return tensor_.layout.element_at(i, j, k, l); } T &tensor_; }; template<size_t N, typename T = double> // struct tensor : tensor_operator<tensor<N,T>, N> { struct tensor : tensor_operator<tensor<N,T> > { static const size_t rank = N; }; I know the workaround, however am interested in mechanics of template instantiation for self-education

  Read the article

• android httpurlconnection [closed]

  - by user620451

  hi im new android developer i am trying to login to my asterisk server passing my username and password it works good but when i am trying to request anther url to the server after login i get access denied and i now the problem because the login connection has disconnected so i want a way to request to urls the first one is login to the server and the second is to do something else after login please help and thx anyway this is a part of my code i want to request this 2 url url1="http://192.168.1.7:8088/rawman?action=login&username=admin&secret=admin" url2="http://192.168.1.5:8088/rawman?action=updateconfig&reload=yes&srcfilename=users.conf&dstfilename=users.conf&Action-000000=newcat&Cat-000000=6001&Var-000000=&Value-000000=" public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tv1 = (TextView) this.findViewById(R.id.display); ed1 = (EditText) this.findViewById(R.id.editText); bt1 = (Button) this.findViewById(R.id.submit); bt1.setOnClickListener(new OnClickListener() { public void onClick(View view) { { try{ ServerRequest(url1); ServerRequest(url2); } catch(Exception e) { Log.v("Exception", "Exception:"+e.getMessage()); } } } }); } public String ServerRequest(String serverString) throws MalformedURLException, IOException { String newFeed=serverString; StringBuilder response = new StringBuilder(); Log.v("server","server url:"+newFeed); URL url = new URL(newFeed); HttpURLConnection httpconn = (HttpURLConnection) url.openConnection(); if(httpconn.getResponseCode()==HttpURLConnection.HTTP_OK) { BufferedReader input = new BufferedReader( new InputStreamReader(httpconn.getInputStream()), 8192); String strLine = null; while ((strLine = input.readLine()) != null) { response.append(strLine); } input.close(); } tv1.settext(response); return response.toString(); }

  Read the article

• addEventListener pass caller as argument

  - by Ryan

  Hi, I have the following code. And my problem is that when clicking, the event is firing but the argument passed is not the correct one. It is passing the last dynamically created row i.e. dataStructure.length value. Anyone knows a solution how to get around this? var table = document.getElementById('output'); for(i =0; i<dataStructure.length; i++){ var row = document.createElement('tr'); row.setAttribute('id', i); var url = dataStructure[i].url; if(document.addEventListener) row.addEventListener('click', function(){handleRowClick(i);}, false); var obj = dataStructure[i]; var cellCount = 0; for(field in obj){ var cell = document.createElement('td'); cell.setAttribute('id', cellCount++); //cell.addEventListener('click', function(){window.open(dataStructureObj.links[i].url);}, false); cell.innerHTML = obj[field]; row.appendChild(cell); } cellCount = 0; table.appendChild(row); } } function handleRowClick(rowClicked){ var rowHTML = rowClicked.innerHTML; var cells = rowHTML.getElementsByTagName('td'); for(cell in cells) { alert(cell.value); } window.open(cells[1].innerHTML); }

  Read the article

• Where does java.util.logging.Logger store their log

  - by Harry Pham

  This might be a stupid question but I am a bit lost with java Logger private static Logger logger = Logger.getLogger("order.web.OrderManager"); logger.info("Removed order " + id + "."); Where do I see the log? Also this quote from java.util.logging.Logger library: On each logging call the Logger initially performs a cheap check of the request level (e.g. SEVERE or FINE) against the effective log level of the logger. If the request level is lower than the log level, the logging call returns immediately. After passing this initial (cheap) test, the Logger will allocate a LogRecord to describe the logging message. It will then call a Filter (if present) to do a more detailed check on whether the record should be published. If that passes it will then publish the LogRecord to its output Handlers. Does this mean that if I have 3 request level log: logger.log(Level.FINE, "Something"); logger.log(Level.WARNING, "Something"); logger.log(Level.SEVERE, "Something"); And my log level is SEVERE, I can see all three logs, if my log level is WARNING, then I cant see SEVERE log, is that correct? And how do I set the log level?

  Read the article

• Problem with "moveable-only types" in VC++ 2010

  - by Luc Touraille

  I recently installed Visual Studio 2010 Professional RC to try it out and test the few C++0x features that are implemented in VC++ 2010. I instantiated a std::vector of std::unique_ptr, without any problems. However, when I try to populate it by passing temporaries to push_back, the compiler complains that the copy constructor of unique_ptr is private. I tried inserting an lvalue by moving it, and it works just fine. #include <utility> #include <vector> int main() { typedef std::unique_ptr<int> int_ptr; int_ptr pi(new int(1)); std::vector<int_ptr> vec; vec.push_back(std::move(pi)); // OK vec.push_back(int_ptr(new int(2)); // compiler error } As it turns out, the problem is neither unique_ptr nor vector::push_back but the way VC++ resolves overloads when dealing with rvalues, as demonstrated by the following code: struct MoveOnly { MoveOnly() {} MoveOnly(MoveOnly && other) {} private: MoveOnly(const MoveOnly & other); }; void acceptRValue(MoveOnly && mo) {} int main() { acceptRValue(MoveOnly()); // Compiler error } The compiler complains that the copy constructor is not accessible. If I make it public, the program compiles (even though the copy constructor is not defined). Did I misunderstand something about rvalue references, or is it a (possibly known) bug in VC++ 2010 implementation of this feature?

  Read the article

• Method having an abstract class as a parameter

  - by Ferhat

  I have an abstract class A, where I have derived the classes B and C. Class A provides an abstract method DoJOB(), which is implemented by both derived classes. There is a class X which has methods inside, which need to call DoJOB(). The class X may not contain any code like B.DoJOB() or C.DoJOB(). Example: public class X { private A foo; public X(A concrete) { foo = concrete; } public FunnyMethod() { foo.DoJOB(); } } While instantiating class X I want to decide which derived class (B or C) must be used. I thought about passing an instance of B or C using the constructor of X. X kewl = new X(new C()); kewl.FunnyMethod(); //calls C.DoJOB() kewl = new X(new B()); kewl.FunnyMethod(); // calls B.DoJOB() My test showed that declaring a method with a parameter A is not working. Am I missing something? How can I implement this correctly? (A is abstract, it cannot be instantiated)

  Read the article

• Procedure expects parameter which was not supplied.

  - by Tony Peterson

  I'm getting the error when accessing a Stored Procedure in SQL Server Server Error in '/' Application. Procedure or function 'ColumnSeek' expects parameter '@template', which was not supplied. This is happening when I call a Stored Procedure with a parameter through .net's data connection to sql (System.data.SqlClient), even though I am supplying the parameter. Here is my code. SqlConnection sqlConn = new SqlConnection(connPath); sqlConn.Open(); // METADATA RETRIEVAL string sqlCommString = "QCApp.dbo.ColumnSeek"; SqlCommand metaDataComm = new SqlCommand(sqlCommString, sqlConn); metaDataComm.CommandType = CommandType.StoredProcedure; SqlParameter sp = metaDataComm.Parameters.Add("@template", SqlDbType.VarChar, 50); sp.Value = Template; SqlDataReader metadr = metaDataComm.ExecuteReader(); And my Stored Procedure is: USE [QCApp] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE [dbo].[ColumnSeek] @template varchar(50) AS EXEC('SELECT Column_Name, Data_Type FROM [QCApp].[INFORMATION_SCHEMA].[COLUMNS] WHERE TABLE_NAME = ' + @template); I'm trying to figure out what I'm doing wrong here. Edit: As it turns out, Template was null because I was getting its value from a parameter passed through the URL and I screwed up the url param passing (I was using @ for and instead of &)

  Read the article

• Communication between lexer and parser

  - by FredOverflow

  Every time I write a simple lexer and parser, I stumble upon the same question: how should the lexer and the parser communicate? I see four different approaches: The lexer eagerly converts the entire input string into a vector of tokens. Once this is done, the vector is fed to the parser which converts it into a tree. This is by far the simplest solution to implement, but since all tokens are stored in memory, it wastes a lot of space. Each time the lexer finds a token, it invokes a function on the parser, passing the current token. In my experience, this only works if the parser can naturally be implemented as a state machine like LALR parsers. By contrast, I don't think it would work at all for recursive descent parsers. Each time the parser needs a token, it asks the lexer for the next one. This is very easy to implement in C# due to the yield keyword, but quite hard in C++ which doesn't have it. The lexer and parser communicate through an asynchronous queue. This is commonly known under the title "producer/consumer", and it should simplify the communication between the lexer and the parser a lot. Does it also outperform the other solutions on multicores? Or is lexing too trivial? Is my analysis sound? Are there other approaches I haven't thought of? What is used in real-world compilers? It would be really cool if compiler writers like Eric Lippert could shed some light on this issue.

  Read the article

• Remote connection to SQL Server Express fails

  - by worlds-apart89

  I have two computers that share the same Internet IP address. Using one of the computers, I can remotely connect to a SQL Server database on the other. Here is my connection string: SqlConnection connection = new SqlConnection(@"Data Source=192.168.1.101\SQLEXPRESSNI,1433;Network Library=DBMSSOCN;Initial Catalog=FirstDB;Persist Security Info=True;User ID=username;Password=password;"); 192.168.1.101 is the server, SQLEXPRESSNI is the SQL Server instance name, and FirstDB is the name of the database. Now, I have another computer with a different Internet IP address. I want to connect to the server above using the third computer that does not belong to my local area network. I dont have access to that third computer at the moment, so I want to use (if possible) the client computer in LAN again. SqlConnection connection = new SqlConnection(@"Data Source=SharedInternetIP\SQLEXPRESSNI,1433;Network Library=DBMSSOCN;Initial Catalog=FirstDB;Persist Security Info=True;User ID=username;Password=password;"); Does not work Note that I am a beginner, so I am not quite sure what I am doing even though I know what I want to do. By passing the Internet IP to the SqlConnection object rather than the local IP address, how can I successfully connect to the server computer, using the client computer in the same network? Also note that my ultimate goal is to connect to the server with an external client, but I don't have access to that computer right now. I'd appreciate any help.

  Read the article

• Terminal-based snake game: input thread manipulates output

  - by enlightened

  I'm writing a snake game for the terminal, i.e. output via print. The following works just fine: while status[snake_monad] do print to_string draw canvas, compose_all([ frame, specs, snake_to_hash(snake[snake_monad]) ]) turn! snake_monad, get_dir move! snake_monad, specs sleep 0.25 end But I don't want the turn!ing to block, of course. So I put it into a new Thread and let it loop: Thread.new do loop do turn! snake_monad, get_dir end end while status[snake_monad] do ... # no turn! here ... end Which also works logically (the snake is turning), but the output is somehow interspersed with newlines. As soon as I kill the input thread (^C) it looks normal again. So why and how does the thread have any effect on my output? And how do I work around this issue? (I don't know much about threads, even less about them in ruby. Input and output concurrently on the same terminal make the matter worse, I guess...) Also (not really important): Wanting my program as pure as possible, would it be somewhat easily possible to get the input non-blockingly while passing everything around? Thank you!

  Read the article

• rails 4 -- working with js format from ajax

  - by user101289

  I'm still working on learning Rails, and I have a page with team information that will get updated based on a team's icon click, which fires an ajax call to the controller to populate some tabs. I've read some good info about how to use format.js in the controller to render a partial from a js.coffee or js.erb file. The problem I'm running into is in the coffeescript I think. Right now, I'm getting some data called @schedules from the controller, and passing it to a schedule.js.coffee file that should populate a partial for each record returned and attach it to a table. // schedule.js.coffee $.each @schedules, (schedule) -> ($ '#schedule_data').append("<%= j render(partial: 'schedules/schedule', locals: { s: schedule }) %>") This throws an error `> undefined local variable or method `schedule' for #<#<Class:0x007fe535cd2900>:0x007fe535d32a30>` I tried simplifying the coffeescript to just log the output: $.each @schedules, (schedule) -> console.log(schedule) but this prints nothing. Am I missing something? I am very inexperienced with coffeescript, but it seems like I should be getting some data-- I verified that the schedule items do exist for this team item.

  Read the article

• Question about Multicaste Delegates?

  - by IbrarMumtaz

  I am going through some exam questions for the 70-536 exam and an actual question one developer postedon his blog has popped up in my exam questions. I cannot remember what his answer was .... but below is the question: You need to write a multicast delegate that accepts a DateTime arguement and returns a bool value. Which code segment should you use? A: public delegate int PowerDeviceOn(bool, DateTime) B: public delegate bool PowerDeviceOn(Object, EventArgs) C: public delegate void PowerDeviceOn(DateTime) D: public delegate bool PowerDeviceOn(DateTime) The answer is A. Can someone please explain why? As I already did some research into this question a while ago and so I was sure that it was C, obviously now looking back at the question its clear that I did not read properly. As i was sure I had seen the same one before so I jumped to the most obvious one. A varitation on this question: You need to write a multicast delegate that accepts a DateTime arguement. Which code segment should you use? A: public delegate int PowerDeviceOn(bool, DateTime) B: public delegate bool PowerDeviceOn(Object, EventArgs) C: public delegate void PowerDeviceOn(DateTime) D: public delegate bool PowerDeviceOn(DateTime) Now this is another variation on this quesiton, it still has the same bogus sample answers, as they still kind work in throwing the exam taker off. Notice how by simply keeping the sample asnwers the same and by removing a small portion of the question text, the answer is C and not A. The variation has no official answer as I just conjured it up using the exam question as a baseplate. The answer is definately C. This time round its easy to see why C is correctr but the very first question I have an inkiling but as you know an inkling is not good enough in passing exams. Thanks For Reading.

  Read the article

• Javascript function objects, this keyword points to wrong object

  - by Rody van Sambeek

  I've got a problem concerning the javascript "this" keyword when used within a javascript functional object. I want to be able to create an object for handling a Modal popup (JQuery UI Dialog). The object is called CreateItemModal. Which i want to be able to instantiate and pass some config settings. One of the config settings. When the show method is called, the dialog will be shown, but the cancel button is not functioning because the this refers to the DOM object instead of the CreateItemModal object. How can I fix this, or is there a better approach to put seperate behaviour in seperate "classes" or "objects". I've tried several approaches, including passing the "this" object into the events, but this does not feel like a clean solution. See (simplified) code below: function CreateItemModal(config) { // initialize some variables including $wrapper }; CreateItemModal.prototype.show = function() { this.$wrapper.dialog({ buttons: { // this crashes because this is not the current object here Cancel: this.close } }); }; CreateItemModal.prototype.close = function() { this.config.$wrapper.dialog('close'); };

  Read the article

• Why is my code stopping and not returning an exception?

  - by BeckyLou

  I have some code that starts a couple of threads to let them execute, then uses a while loop to check for the current time passing a set timeout period, or for the correct number of results to have been processed (by checking an int on the class object) (with a Thread.Sleep() to wait between loops) Once the while loop is set to exit, it calls Abort() on the threads and should return data to the function that calls the method. When debugging and stepping through the code, I find there can be exceptions in the code running on the separate threads, and in some cases I handle these appropriately, and at other times I don't want to do anything specific. What I have been seeing is that my code goes into the while loop and the thread sleeps, then nothing is returned from my function, either data or an exception. Code execution just stops completely. Any ideas what could be happening? Code sample: System.Threading.Thread sendThread = new System.Threading.Thread(new System.Threading.ThreadStart(Send)); sendThread.Start(); System.Threading.Thread receiveThread = new System.Threading.Thread(new System.Threading.ThreadStart(Receive)); receiveThread.Start(); // timeout Int32 maxSecondsToProcess = this.searchTotalCount * timeout; DateTime timeoutTime = DateTime.Now.AddSeconds(maxSecondsToProcess); Log("Submit() Timeout time: " + timeoutTime.ToString("yyyyMMdd HHmmss")); // while we're still waiting to receive results & haven't hit the timeout, // keep the threads going while (resultInfos.Count < this.searchTotalCount && DateTime.Now < timeoutTime) { Log("Submit() Waiting..."); System.Threading.Thread.Sleep(10 * 1000); // 1 minute } Log("Submit() Aborting threads"); // <== this log doesn't show up sendThread.Abort(); receiveThread.Abort(); return new List<ResultInfo>(this.resultInfos.Values);

  Read the article

• Variable length argument list - How to understand we retrieved the last argument?

  - by hkBattousai

  I have a Polynomial class which holds coefficients of a given polynomial. One of its overloaded constructors is supposed to receive these coefficients via variable argument list. template <class T> Polynomial<T>::Polynomial(T FirstCoefficient, ...) { va_list ArgumentPointer; va_start(ArgumentPointer, FirstCoefficient); T NextCoefficient = FirstCoefficient; std::vector<T> Coefficients; while (true) { Coefficients.push_back(NextCoefficient); NextCoefficient = va_arg(ArgumentPointer, T); if (/* did we retrieve all the arguments */) // How do I implement this? { break; } } m_Coefficients = Coefficients; } I know that we usually pass an extra parameter which tells the recipient method the total number of parameters, or we pass a sentimental ending parameter. But in order to keep thing short and clean, I don't prefer passing an extra parameter. Is there any way of doing this without modifying the method signature in the example?

  Read the article

• Cannot pass null to server using jQuery AJAX. Value received at the server is the string "null".

  - by Tom

  I am converting a javascript/php/ajax application to use jQuery to ensure compatibility with browsers other than Firefox. I am having trouble passing true, false, and null values using jQuery's ajax function. Javascript code: $.ajax ( { url : <server_url>, dataType: 'json', type : 'POST', success : receiveAjaxMessage, data: { valueTrue : true, valueFalse : false, valueNull : null } } ); PHP code: var_dump($_POST); Server output: array(3) { ["valueTrue"]=> string(4) "true" ["valueFalse"]=> string(5) "false" ["valueNull"]=> string(4) "null" } The problem is that the null, true, and false values are being converted to strings. The Javascript AJAX code currently in use passes null, true, and false correctly but only works in Firefox. Does anyone know how to solve this problem using jQuery? Here is some working code (not using jQuery) to compare with the code not-working code given above. Javascript Code: ajaxPort.send ( <server_url>, { valueTrue : true, valueFalse : false, valueNull : null } ); PHP code: var_dump(json_decode(file_get_contents('php://input'), true)); Server output: array(3) { ["valueTrue"]=> bool(true) ["valueFalse"]=> bool(false) ["valueNull"]=> NULL } Note that the null, true, and false values are correctly received. Note also that in the second method the $_POST array is not used in the PHP code. I think this is the key to the problem, but I cannot find a way to replicate this behavior using jQuery.

  Read the article

< Previous Page | 538 539 540 541 542 543 544 545 546 547 548 549  | Next Page >