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  • Linq is returning too many results when joined

    - by KallDrexx
    In my schema I have two database tables. relationships and relationship_memberships. I am attempting to retrieve all the entries from the relationship table that have a specific member in it, thus having to join it with the relationship_memberships table. I have the following method in my business object: public IList<DBMappings.relationships> GetRelationshipsByObjectId(int objId) { var results = from r in _context.Repository<DBMappings.relationships>() join m in _context.Repository<DBMappings.relationship_memberships>() on r.rel_id equals m.rel_id where m.obj_id == objId select r; return results.ToList<DBMappings.relationships>(); } _Context is my generic repository using code based on the code outlined here. The problem is I have 3 records in the relationships table, and 3 records in the memberships table, each membership tied to a different relationship. 2 membership records have an obj_id value of 2 and the other is 3. I am trying to retrieve a list of all relationships related to object #2. When this linq runs, _context.Repository<DBMappings.relationships>() returns the correct 3 records and _context.Repository<DBMappings.relationship_memberships>() returns 3 records. However, when the results.ToList() executes, the resulting list has 2 issues: 1) The resulting list contains 6 records, all of type DBMappings.relationships(). Upon further inspection there are 2 for each real relationship record, both are an exact copy of each other. 2) All relationships are returned, even if m.obj_id == 3, even though objId variable is correctly passed in as 2. Can anyone see what's going on because I've spent 2 days looking at this code and I am unable to understand what is wrong. I have joins in other linq queries that seem to be working great, and my unit tests show that they are still working, so I must be doing something wrong with this. It seems like I need an extra pair of eyes on this one :)

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  • Is it safe to use random Unicode for complex delimiter sequences in strings?

    - by ccomet
    Question: In terms of program stability and ensuring that the system will actually operate, how safe is it to use chars like ¦, § or ‡ for complex delimiter sequences in strings? Can I reliable believe that I won't run into any issues in a program reading these incorrectly? I am working in a system, using C# code, in which I have to store a fairly complex set of information within a single string. The readability of this string is only necessary on the computer side, end-users should only ever see the information after it has been parsed by the appropriate methods. Because some of the data in these strings will be collections of variable size, I use different delimiters to identify what parts of the string correspond to a certain tier of organization. There are enough cases that the standard sets of ;, |, and similar ilk have been exhausted. I considered two-char delimiters, like ;# or ;|, but I felt that it would be very inefficient. There probably isn't that large of a performance difference in storing with one char versus two chars, but when I have the option of picking the smaller option, it just feels wrong to pick the larger one. So finally, I considered using the set of characters like the double dagger and section. They only take up one char, and they are definitely not going to show up in the actual text that I'll be storing, so they won't be confused for anything. But character encoding is finicky. While the visibility to the end user is meaningless (since they, in fact, won't see it), I became recently concerned about how the programs in the system will read it. The string is stored in one database, while a separate program is responsible for both encoding and decoding the string into different object types for the rest of the application to work with. And if something is expected to be written one way, is possibly written another, then maybe the whole system will fail and I can't really let that happen. So is it safe to use these kind of chars for background delimiters?

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  • Dual usage of asp.net mvc and php under same domain

    - by jim
    Hello all, I've got a scenario where we have a customer who has a linux hosted php app (joomla) that they wish to integrate with some back-end asp.net mvc functionality that was created for a 'sister' site. Basically, the mvc site has prices and stock availability methods which (in the sister site) populates dropdown lists and other 'order' style info on the pages. I've been tasked with looking at the integration options to allow the php site to use this info as a 'service'. (as ever, these guys are looking at cost of ownership, maintenence etc, so this is their preferred route) Has anyone done anything similar with success?? I'd imagine (much like the sister site) liberal doses of ajax will be employed in order to populate portions of the page on demand. So this may have a bearing on any suggestions that you may have. Also, the methods that are being called ultimately end up populating the same database, so there are no issues with correlating the ID's across the different platforms. I don't really want to go down any 'iframe' type route if at all possible, tho' reality may dictate this as being an option. I'm possibly (naively) imagining that i could simply invoke the mvc functions directly from the php app with some sort of 'session' variable being passed for authentication. pretty tall order or pretty straightfwd?? cheers jim

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  • (Not So) Silly Objective-C inheritance problem when using property - GCC Bug?

    - by Ben Packard
    Update 2 - Many people are insisting I need to declare an iVar for the property. Some are saying not so, as I am using Modern Runtime (64 bit). I can confirm that I have been successfully using @property without iVars for months now. Therefore, I think the 'correct' answer is an explanation as to why on 64bit I suddenly have to explicitly declare the iVar when (and only when) i'm going to access it from a child class. The only one I've seen so far is a possible GCC bug (thanks Yuji). Not so simple after all... Update - I messed up one line of the original copy and paste - corrected. The @property call was missing (nonatomic, retain) but is a red herring - STILL NEED AN ANSWER! Thanks. I've been scratching my head with this for a couple of hours - I haven't used inheritance much. Here I have set up a simple Test B class that inherits from Test A, where an ivar is declared. But I get the compilation error that the variable is undeclared. This only happens when I add the property and synthesize declarations - works fine without them. TestA Header: #import <Cocoa/Cocoa.h> @interface TestA : NSObject { NSString *testString; } @end TestA Implementation is empty: #import "TestA.h" @implementation TestA @end TestB Header: #import <Cocoa/Cocoa.h> #import "TestA.h" @interface TestB : TestA { } @property (nonatomic, retain) NSString *testProp; @end TestB Implementation (Error - 'testString' is undeclared) #import "TestB.h" @implementation TestB @synthesize testProp; - (void)testing{ NSLog(@"test ivar is %@", testString); } @end

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  • How can I set up an editor to work with Git on Windows?

    - by Patrick McElhaney
    I'm trying out Git on Windows. I got to the point of trying "git commit" and I got this error: Terminal is dumb but no VISUAL nor EDITOR defined. Please supply the message using either -m or -F option. So I figured out I need to have an environment variable called EDITOR. No problem. I set it to point to Notepad. That worked, almost. The default commit message opens in Notepad. But Notepad doesn't support bare line feeds. I went out and got Notepad++. But I can't figure out how to get Notepad++ set up as the %EDITOR% in such a way that it works with Git as expected. I'm not married to Notepad++. At this point I couldn't care less what editor I use. I just want to be able to type my commit messages without using -m. So, for those of you using Git on Windows: What (free) tool do you use to edit your commit message, and what do you get when you type echo %EDITOR% at the command prompt?

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  • nhibernate fluent repository pattern insert problem

    - by voam
    I am trying to use Fluent NHibernate and the repository pattern. I would like my business layer to not be knowledgeable of the data persistence layer. Ideally I would pass in an initialized domain object to the insert method of the repository and all would be well. Where I run into problems is if the object being passed in has a child object. For example say I want to insert an a new order for a customer, and the customer is a property of the order object. I would like to do something like this: Customer c = new Customer; c.CustomerId = 1; Order o = new Order; o.Customer = c; repository.InsertOrder(o); The problem is that using NHiberate the CustomerId field is only privately settable so I can not set it directly like this. so what I have ended up doing is have my repository have an interface of Order InsertOrder(int customerId) where all the foreign keys get passed in as parameters. Somehow this just doesn't seem right. The other approach was to use the NHibernate session variable to load a customer object in my business model and then have the order passed in to the repository but this defeats my persistence ignorance ideal. Should I throw this persistence ignorance out the window or am I missing something here? Thanks

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  • What happened to the .NET version definition with v4.0?

    - by Tom Tresansky
    I'm building a C# class library, and using the beta 2 of Visual Web Developer/Visual C# 2010. I'm trying to save information about what version of .NET the library was built under. In the past, I was able to use this: // What version of .net was it built under? #if NET_1_0 public const string NETFrameworkVersion = ".NET 1.0"; #elif NET_1_1 public const string NETFrameworkVersion = ".NET 1.1"; #elif NET_2_0 public const string NETFrameworkVersion = ".NET 2.0"; #elif NET_3_5 public const string NETFrameworkVersion = ".NET 3.5"; #else public const string NETFrameworkVersion = ".NET version unknown"; #endif So I figured I could just add: #elif NET_4_0 public const string NETFrameworkVersion = ".NET 4.0"; Now, in Project-Properties, my target Framework is ".NET Framework 4". If I check: Assembly.GetExecutingAssembly().ImageRuntimeVersion I can see my runtime version is v4.0.21006 (so I know I have .NET 4.0 installed on my CPU). I naturally expect to see that my NETFrameworkVersion variable holds ".NET 4.0". It does not. It holds ".NET version unknown". So my question is, why is NET_4_0 not defined? Did the naming convention change? Is there some simple other way to determine .NET framework build version in versions 3.5?

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  • Webfaction apache + mod_wsgi + django configuration issue

    - by Dmitry Guyvoronsky
    A problem that I stumbled upon recently, and, even though I solved it, I would like to hear your opinion of what correct/simple/adopted solution would be. I'm developing website using Django + python. When I run it on local machine with "python manage.py runserver", local address is http://127.0.0.1:8000/ by default. However, on production server my app has other url, with path - like "http://server.name/myproj/" I need to generate and use permanent urls. If I'm using {% url view params %}, I'm getting paths that are relative to / , since my urls.py contains this urlpatterns = patterns('', (r'^(\d+)?$', 'myproj.myapp.views.index'), (r'^img/(.*)$', 'django.views.static.serve', {'document_root': settings.MEDIA_ROOT + '/img' }), (r'^css/(.*)$', 'django.views.static.serve', {'document_root': settings.MEDIA_ROOT + '/css' }), ) So far, I see 2 solutions: modify urls.py, include '/myproj/' in case of production run use request.build_absolute_uri() for creating link in views.py or pass some variable with 'hostname:port/path' in templates Are there prettier ways to deal with this problem? Thank you. Update: Well, the problem seems to be not in django, but in webfaction way to configure wsgi. Apache configuration for application with URL "hostname.com/myapp" contains the following line WSGIScriptAlias / /home/dreamiurg/webapps/pinfont/myproject.wsgi So, SCRIPT_NAME is empty, and the only solution I see is to get to mod_python or serve my application from root. Any ideas?

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  • Bind button visibility to the expresion (C#)

    - by drasto
    I have a delete button in each row of GridView (component ASP.NET). I want some of the delete buttons to be invisible. The visibility of the delete button should depend on the data that are back the row. GridView is backed by EntityDataSource. GridView displays entities called Category, one instance in each row. Entity Category has (besides others) also a field of type EntityCollection. Name of that field is Items. Basically I want to allow user to delete a row only if the Items field of backing Category entity is an empty collection. I cannot make up the binding of Visible property. I have no experience with bindings and Google does not really help. This is how the button looks right now: <asp:Button ID="DeleteButton" runat="server" CommandName="Delete" Text="Delete" Visible=??? ></asp:Button> I don't know what should replace ???. The button schold be visible only when this expression evaluates to true: ((SimpleEShop.Model.Category) dataItem).Items.LongCount() <= 0 where dataItem variable contains data of current row in the table. What is the binding that I need ?

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  • Binary files printing and desired precision

    - by yCalleecharan
    Hi, I'm printing a variable say z1 which is a 1-D array containing floating point numbers to a text file so that I can import into Matlab or GNUPlot for plotting. I've heard that binary files (.dat) are smaller than .txt files. The definition that I currently use for printing to a .txt file is: void create_out_file(const char *file_name, const long double *z1, size_t z_size){ FILE *out; size_t i; if((out = _fsopen(file_name, "w+", _SH_DENYWR)) == NULL){ fprintf(stderr, "***> Open error on output file %s", file_name); exit(-1); } for(i = 0; i < z_size; i++) fprintf(out, "%.16Le\n", z1[i]); fclose(out); } I have three questions: Are binary files really more compact than text files?; If yes, I would like to know how to modify the above code so that I can print the values of the array z1 to a binary file. I've read that fprintf has to be replaced with fwrite. My output file say dodo.dat should contain the values of array z1 with one floating number per line. I have %.16Le up in my code but I think that %.15Le is right as I have 15 precision digits with long double. I have put a dot (.) in the width position as I believe that this allows expansion to an arbitrary field to hold the desired number. Am I right? As an example with %.16Le, I can have an output like 1.0047914240730432e-002 which gives me 16 precision digits and the width of the field has the right width to display the number correctly. Is placing a dot (.) in the width position instead of a width value a good practice? Thanks a lot...

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  • Wait on multiple condition variables on Linux without unnecessary sleeps?

    - by Joseph Garvin
    I'm writing a latency sensitive app that in effect wants to wait on multiple condition variables at once. I've read before of several ways to get this functionality on Linux (apparently this is builtin on Windows), but none of them seem suitable for my app. The methods I know of are: Have one thread wait on each of the condition variables you want to wait on, which when woken will signal a single condition variable which you wait on instead. Cycling through multiple condition variables with a timed wait. Writing dummy bytes to files or pipes instead, and polling on those. #1 & #2 are unsuitable because they cause unnecessary sleeping. With #1, you have to wait for the dummy thread to wake up, then signal the real thread, then for the real thread to wake up, instead of the real thread just waking up to begin with -- the extra scheduler quantum spent on this actually matters for my app, and I'd prefer not to have to use a full fledged RTOS. #2 is even worse, you potentially spend N * timeout time asleep, or your timeout will be 0 in which case you never sleep (endlessly burning CPU and starving other threads is also bad). For #3, pipes are problematic because if the thread being 'signaled' is busy or even crashes (I'm in fact dealing with separate process rather than threads -- the mutexes and conditions would be stored in shared memory), then the writing thread will be stuck because the pipe's buffer will be full, as will any other clients. Files are problematic because you'd be growing it endlessly the longer the app ran. Is there a better way to do this? Curious for answers appropriate for Solaris as well.

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  • Store variables during loop and use in it another template

    - by krisvandenbergh
    Is there a way to store a variable/param during a for-each loop in a sort of array, and use it in another template, namely <xsl:template match="Foundation.Core.Classifier.feature">. All the classname values that appear during the for-each should be stored. How would you implement that in XSLT? Here's my current code. <xsl:for-each select="Foundation.Core.Class"> <xsl:for-each select="Foundation.Core.ModelElement.name"> <xsl:param name="classname"> <xsl:value-of select="Foundation.Core.ModelElement.name"/> </xsl:param> </xsl:for-each> <xsl:apply-templates select="Foundation.Core.Classifier.feature" /> </xsl:for-each> Here's the template in which the classname parameters should be used. <xsl:template match="Foundation.Core.Classifier.feature"> <xsl:for-each select="Foundation.Core.Attribute"> <owl:DatatypeProperty rdf:ID="{Foundation.Core.ModelElement.name}"> <rdfs:domain rdf:resource="$classname" /> </owl:DatatypeProperty> </xsl:for-each> </xsl:template> The input file can be found at http://krisvandenbergh.be/uml_pricing.xml

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  • Read XML with PHP

    - by sea_1987
    I am trying to check a field in some XML that is returned from an outside. The XML is returned in a variable call $out and when you view the source of the page you get a XML output of the following, <?xml version="1.0" encoding="UTF-8"?> <ResponseBlock Live="FALSE" Version="3.51"> <Response Type="AUTH"> <OperationResponse> <TransactionReference>23-9-1334895</TransactionReference> <TransactionCompletedTimestamp>2010-04-30 15:59:05</TransactionCompletedTimestamp> <AuthCode>AUTH CODE:TEST</AuthCode> <TransactionVerifier>AlaUOS1MOnN/iwc5s2WPDm5ggrCLwesUnHs9h+W0N3CRaln2W6lh+6dtaRFFhLdwfnw6y7lRemyJUYl9a3dpWfzORE6DaZkFMb+dIb0Ne1UxjFEJkrEtjzx/i8KSayrIBrT/yGZOoOT42EZ9loc+UkdGk/pqYvj8bZztvgBNo2Ak=</TransactionVerifier> <Result>1</Result> <SettleStatus>0</SettleStatus> <SecurityResponseSecurityCode>1</SecurityResponseSecurityCode> <SecurityResponsePostCode>1</SecurityResponsePostCode> <SecurityResponseAddress>1</SecurityResponseAddress> </OperationResponse> <Order> <OrderInformation>This is a test order</OrderInformation> <OrderReference>Order0001</OrderReference> </Order> </Response> </ResponseBlock> I want check what value is in the 'Result' field. I am unsure how to access the information using PHP, so far I have, $xml = simplexml_load_string($out); Many Thanks

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  • How to load a library that depends on another library, all from a jar file

    - by Philip
    I would like to ship my application as a self-contained jar file. The jar file should contain all the class files, as well as two shared libraries. One of these shared libraries is written for the JNI and is essentially an indirection to the other one (which is 100% C). I have first tried running my jar file without the libraries, but having them accessible through the LD_LIBRARY_PATH environment variable. That worked fine. I then put the JNI library into the jar file. I have read about loading libraries from jar files by copying them first to some temporary directory, and that worked well for me (note that the 100% C library was, I suppose, loaded as before). Now I want to put both libraries into the jar, but I don't understand how I can make sure that they will both be loaded. Sure I can copy them both to a temporary directory, but when I load the "indirection" one, it always gives me: java.lang.UnsatisfiedLinkError: /tmp/.../libindirect.so: /libpure.so: cannot open shared object file: No such file or directory I've tried to force the JVM to load the "100% C" library first by explicitely calling System.load(...) on its temporary file, but that didn't work better. I suspect the system is looking for it when resolving the links in libindirect.so but doesn't care about what the JVM loaded. Can anyone help me on that one? Thanks

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  • UITableViewCell imageView images loading small even when they are the correct size!

    - by Alex Barlow
    Im having an issue whilst loading images into a UITableViewCell after an asynchronous download and placement into an UIImage variable.. The images appear smaller than they actually are! But when scrolled down and scrolled back up to the image, or the whole table is reloaded, they appear at the correct size... Here is a code excerpt... - (void)reviewImageDidLoad:(NSIndexPath *)indexPath { ThumbDownloader *thumbDownloader = [imageDownloadsInProgress objectForKey:indexPath]; if (thumbDownloader != nil) { UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:thumbDownloader.indexPathInTableView]; [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:0.4]; [self.tableView cellForRowAtIndexPath:indexPath].imageView.alpha = 0.0; [UIView commitAnimations]; cell.imageView.image = thumbDownloader.review.thumb; [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:0.4]; [self.tableView cellForRowAtIndexPath:indexPath].imageView.alpha = 1.0; [UIView commitAnimations]; } } Here is an image of the app just after calling this method.. http://www.flickr.com/photos/arbarlow/5288563627/ After calling tableView reloadData or scrolling around the appear correctly, go the the next flickr image, to see the normal result, but im sure you can guess that.. Does anyone have an ideas as to make the images appear correctly? im absolutely stumped?! Regards, Alex iPhone noob

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  • ListBox and Listview problem

    - by Anu
    Hi, I have listbox in my applcation and corresponding coding.. XAML: <DataTemplate x:Key="menuItemTemplate"> <WrapPanel> <TextBlock Text="{Binding Path = Menu}" /> </WrapPanel> </DataTemplate> <ListBox x:Name="menubox" ItemsSource="{Binding}" ItemTemplate="{StaticResource menuItemTemplate}" Margin="0,5,0,0"> .CS : public void Add(string[] menu) { ItemList items = ItemList.Load(menu); DataContext = items; } It works fine.Later i add Listview for another purpose and i coded like the same way of listbox XAML: <DataTemplate x:Key="ListItemTemplate"> <WrapPanel> <TextBlock Text="{Binding Path = Title}" /> </WrapPanel> </DataTemplate> <ListView ItemsSource="{Binding}" ItemTemplate="{StaticResource ListItemTemplate}" Name="listView1" /> .cs coding: public void SetTree(string Title,int BoxNo ) { TreeList items1 = TreeList.Load(Title,BoxNo); DataContext = items1; } After adding Listview,what happended this ListView show data,but Listbox didnot show anything.When i click the listbox it perfectly executing the clicking event of listbox.Only problem it doesnot display the text.What can i do for that. Here i added corresponding list class pls see tht. namespace Tabcontrol { public class TreeList : Collection<TreeItems> { public int size; public TreeList() { size = 0; } public int Count { get { return size; } } public static TreeList Load(string pmenu,int Box) { TreeList result = new TreeList(); TreeItems item = TreeItems.Load(pmenu,Box); result.Add(item); return result; } } } The ItemList class also the same thing, only variable names are getting differred.

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  • Button Onclick event (which is in codbehind) doesn't get triggered in MVC 2

    - by rksprst
    I had an MVC 1.0 web application that was in VS 2008; I just upgraded the project to VS 2010 which automatically upgraded MVC to 2.0. I have a bunch of viewpages have codebehind files that were manually added. The project worked fine before the upgrade, but now the onclick even't don't get triggered. I.e. I have an asp:button with an onclick event that points to a method in the codebehind. When you click the button, the onclick event doesn't get triggered. In fact, when you look at the Page variable, IsPostBack is false. This is really bizarre and I'm wondering if anyone know what happened and how to fix it. I'm thinking it has something to do with the changes in MVC 2.0; but I'm not sure. Any help is really appreciated, I've been trying to figure this out for a while. (deleting the codebehinds and moving that to the controller is not really an option since there is so many pages, moving back to vs 2008 is a last resort as I want to make use of some of the VS 2010 features like performance testing.)

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  • Protecting an Application's Memory From Tampering

    - by Changeling
    We are adding AES 256 bit encryption to our server and client applications for encrypting the TCP/IP traffic containing sensitive information. We will be rotating the keys daily. Because of that, the keys will be stored in memory with the applications. Key distribution process: Each server and client will have a list of initial Key Encryption Key's (KEK) by day If the client has just started up or the server has just started up, the client will request the daily key from the server using the initial key. The server will respond with the daily key, encrypted with the initial key. The daily key is a randomly generated set of alphanumeric characters. We are using AES 256 bit encryption. All subsequent communications will be encrypted using that daily key. Nightly, the client will request the new daily key from the server using the current daily key as the current KEK. After the client gets the new key, the new daily key will replace the old daily key. Is it possible for another bad application to gain access to this memory illegally or is this protected in Windows? The key will not be written to a file, only stored in a variable in memory. If an application can access the memory illegally, how can you protect the memory from tampering? We are using C++ and XP (Vista/7 may be an option in the future so I don't know if that changes the answer).

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  • SQL Distinct keyword in assignment statement

    - by Brandi
    I have a query that works: DECLARE @ProductID int SET @ProductID = '1234' SELECT DISTINCT TOP 12 a.ProductID FROM A a WHERE a.CategoryID IN (SELECT b.CategoryID FROM B b WHERE b.ProductID = @ProductID) AND a.ProductID != @ProductID It returns a list of 12 product numbers, all unique. I need to store these results in a variable, comma separated, because that's what 3rd party stored procedure needs. So I have this: DECLARE @ProductID int DECLARE @relatedprods varchar(8000) SET @ProductID = '1234' SET @relatedprods = '' SELECT TOP 12 @relatedprods = @relatedprods + CONVERT(VARCHAR(20), a.ProductID) + ', ' FROM A a WHERE a.CategoryID IN (SELECT b.CategoryID FROM B b WHERE B.ProductID = @ProductID) AND a.ProductID != @ProductID SELECT @relatedprods Now, none of these are distinct, but it is returning 12 rows. Now I add the 'distinct' back in, like in the first query: DECLARE @ProductID int DECLARE @relatedprods varchar(8000) SET @ProductID = '1234' SET @relatedprods = '' SELECT DISTINCT TOP 12 @relatedprods = @relatedprods + CONVERT(VARCHAR(20), a.ProductID) + ', ' FROM A a WHERE a.CategoryID IN (SELECT b.CategoryID FROM B b WHERE B.ProductID = @ProductID) AND a.ProductID != @ProductID SELECT @relatedprods Only one product is returned in the comma separated list! Does 'distinct' not work in assignment statements? What did I do wrong? Or is there a way to get around this? Thanks in advance!

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  • C# parameters by reference and .net garbage collection

    - by Yarko
    I have been trying to figure out the intricacies of the .NET garbage collection system and I have a question related to C# reference parameters. If I understand correctly, variables defined in a method are stored on the stack and are not affected by garbage collection. So, in this example: public class Test { public Test() { } public int DoIt() { int t = 7; Increment(ref t); return t; } private int Increment(ref int p) { p++; } } the return value of DoIt() will be 8. Since the location of t is on the stack, then that memory cannot be garbage collected or compacted and the reference variable in Increment() will always point to the proper contents of t. However, suppose we have: public class Test { private int t = 7; public Test() { } public int DoIt() { Increment(ref t); return t; } private int Increment(ref int p) { p++; } } Now, t is stored on the heap as it is a value of a specific instance of my class. Isn't this possibly a problem if I pass this value as a reference parameter? If I pass t as a reference parameter, p will point to the current location of t. However, if the garbage collector moves this object during a compact, won't that mess up the reference to t in Increment()? Or does the garbage collector update even references created by passing reference parameters? Do I have to worry about this at all? The only mention of worrying about memory being compacted on MSDN (that I can find) is in relation to passing managed references to unmanaged code. Hopefully that's because I don't have to worry about any managed references in managed code. :)

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  • How to asynchronously read to std::string using Boost::asio?

    - by SpyBot
    Hello. I'm learning Boost::asio and all that async stuff. How can I asynchronously read to variable user_ of type std::string? Boost::asio::buffer(user_) works only with async_write(), but not with async_read(). It works with vector, so what is the reason for it not to work with string? Is there another way to do that besides declaring char user_[max_len] and using Boost::asio::buffer(user_, max_len)? Also, what's the point of inheriting from boost::enable_shared_from_this<Connection> and using shared_from_this() instead of this in async_read() and async_write()? I've seen that a lot in the examples. Here is a part of my code: class Connection { public: Connection(tcp::acceptor &acceptor) : acceptor_(acceptor), socket_(acceptor.get_io_service(), tcp::v4()) { } void start() { acceptor_.get_io_service().post( boost::bind(&Connection::start_accept, this)); } private: void start_accept() { acceptor_.async_accept(socket_, boost::bind(&Connection::handle_accept, this, placeholders::error)); } void handle_accept(const boost::system::error_code& err) { if (err) { disconnect(); } else { async_read(socket_, boost::asio::buffer(user_), boost::bind(&Connection::handle_user_read, this, placeholders::error, placeholders::bytes_transferred)); } } void handle_user_read(const boost::system::error_code& err, std::size_t bytes_transferred) { if ( err or (bytes_transferred != sizeof(user_)) ) { disconnect(); } else { ... } } ... void disconnect() { socket_.shutdown(tcp::socket::shutdown_both); socket_.close(); socket_.open(tcp::v4()); start_accept(); } tcp::acceptor &acceptor_; tcp::socket socket_; std::string user_; std::string pass_; ... };

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  • BackgroundWorker and instance variables

    - by Alastair Pitts
    One thing that's always confused me is how a BackgroundWorker seems to have thread-safe access to the instance variables of the surrounding class. Given a basic class: public class BackgroundProcessor { public List<int> Items { get; private set; } public BackgroundProcessor(IEnumerable<int> items) { Items = new List<int>(items); } public void DoWork() { BackgroundWorker worker = new BackgroundWorker(); worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted); worker.DoWork += new DoWorkEventHandler(worker_DoWork); worker.RunWorkerAsync(); } void worker_DoWork(object sender, DoWorkEventArgs e) { var processor = new ProcessingClass(); processor.Process(this.Points); //Accessing the instance variable } void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { //Stuff goes here } } Am I erroneous in my assumption the the call to processor.Process(this.Points); is a thread-safe call? How don't I get a cross-thread access violation? I'm sure it's obvious, but it always has confused me.

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  • insert Query is not executing, help me in tracking the problem

    - by Parth
    I tried the below query but it didnt executed giving error as : 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1 INSERT INTO `jos_menu` SET params = 'orderby= show_noauth= show_title= link_titles= show_intro= show_section= link_section= show_category= link_category= show_author= show_create_date= show_modify_date= show_item_navigation= show_readmore= show_vote= show_icons= show_pdf_icon= show_print_icon= show_email_icon= show_hits= feed_summary= page_title= show_page_title=1 pageclass_sfx= menu_image=-1 secure=0 ', checked_out_time = '0000-00-00 00:00:00', ordering = '13', componentid = '20', published = '1', id = '152', menutype = 'accmenu', name = 'IPL', alias = 'ipl', link = 'index.php?option=com_content&view=archive', type = 'component') then i used mysql_real_escape_string() on the query containing variable which gives me the query as : INSERT INTO `jos_menu` SET params = \'orderby=\nshow_noauth=\nshow_title=\nlink_titles=\nshow_intro=\nshow_section=\nlink_section=\nshow_category=\nlink_category=\nshow_author=\nshow_create_date=\nshow_modify_date=\nshow_item_navigation=\nshow_readmore=\nshow_vote=\nshow_icons=\nshow_pdf_icon=\nshow_print_icon=\nshow_email_icon=\nshow_hits=\nfeed_summary=\npage_title=\nshow_page_title=1\npageclass_sfx=\nmenu_image=-1\nsecure=0\n\n\', checked_out_time = \'0000-00-00 00:00:00\', ordering = \'13\', componentid = \'20\', published = \'1\', id = \'152\', menutype = \'accmenu\', name = \'IPL\', alias = \'ipl\', link = \'index.php?option=com_content&view=archive\', type = \'component\') And on executing the above query I get an error as : 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '\'orderby=\nshow_noauth=\nshow_title=\nlink_titles=\nshow_intro=\nshow_section=\' at line 1 Can Someone guide me to track the problem in it? Thanks In Advance....

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  • How to find/extract data from xml with jQuery

    - by darryl
    I'm trying to extract the StateLongName and StateShortName values from the xml below. I know there has to be a simple elegant way to do this with jQuery. <NewDataSet> <Table> <StateLongName>Alabama</StateLongName> <StateShortName>AL</StateShortName> </Table> <Table> <StateLongName>Alaska</StateLongName> <StateShortName>AK</StateShortName> </Table> ...elments removed for brevity </NewDataSet> Here's what I've tried. Load the xml from above into a Javascript variable name xml. Try #1 $(xml).find("TABLE").each(function() { var stateName = $(this).find("StateLongName").innerText; var stateCode = $(this).find("StateShortName").innerText; }); Try #1 doesn't find anything and never goes inside to load the stateName and stateCode variables. Try #2 $(xml).find("StateLongName").each(function() { var stateName = $(this).find("StateLongName").innerText; var stateCode = $(this).find("StateShortName").innerText; }); Try #2 does find matches, however the stateName and stateCode are left undefined. Try #3 $(xml).find("StateLongName").each(function() { var stateName = $($(xml).find('StateLongName').parent()[0].innerHTML)[1].data; var stateCode = $($(xml).find('StateLongName').parent()[0].innerHTML)[5].data; }); Try #3 works but there has to be a better way. Please enlighten me. Thanks for you time!

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  • Why does one of these statements compile in Scala but not the other?

    - by Jeff
    (Note: I'm using Scala 2.7.7 here, not 2.8). I'm doing something pretty simple -- creating a map based on the values in a simple, 2-column CSV file -- and I've completed it easily enough, but I'm perplexed at why my first attempt didn't compile. Here's the code: // Returns Iterator[String] private def getLines = Source.fromFile(csvFilePath).getLines // This doesn't compile: def mapping: Map[String,String] = { Map(getLines map { line: String => val pairArr = line.split(",") pairArr(0) -> pairArr(1).trim() }.toList:_*) } // This DOES compile def mapping: Map[String,String] = { def strPair(line: String): (String,String) = { val pairArr = line.split(",") pairArr(0) -> pairArr(1).trim() } Map(getLines.map( strPair(_) ).toList:_*) } The compiler error is CsvReader.scala:16: error: value toList is not a member of (St ring) = (java.lang.String, java.lang.String) [scalac] possible cause: maybe a semicolon is missing before `value toList'? [scalac] }.toList:_*) [scalac] ^ [scalac] one error found So what gives? They seem like they should be equivalent to me, apart from the explicit function definition (vs. anonymous in the nonworking example) and () vs. {}. If I replace the curly braces with parentheses in the nonworking example, the error is "';' expected, but 'val' found." But if I remove the local variable definition and split the string twice AND use parens instead of curly braces, it compiles. Can someone explain this difference to me, preferably with a link to Scala docs explaining the difference between parens and curly braces when used to surround method arguments?

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