Search Results

Search found 14402 results on 577 pages for 'interface builder'.

Page 502/577 | < Previous Page | 498 499 500 501 502 503 504 505 506 507 508 509  | Next Page >

• Java generics question with wildcards

  - by Sean

  Just came across a place where I'd like to use generics and I'm not sure how to make it work the way I want. I have a method in my data layer that does a query and returns a list of objects. Here's the signature. public List getList(Class cls, Map query) This is what I'd like the calling code to look like. List<Whatever> list = getList(WhateverImpl.class, query); I'd like to make it so that I don't have to cast this to a List coming out, which leads me to this. public <T> List<T> getList(Class<T> cls, Map query) But now I have the problem that what I get out is always the concrete List<WhateverImpl> passed in whereas I'd like it to be the Whatever interface. I tried to use the super keyword but couldn't figure it out. Any generics gurus out there know how this can be done?

  Read the article

• R: building a simple command line plotting tool/Capturing window close events

  - by user275455

  I am trying to use R within a script that will act as a simple command line plot tool. I.e. user pipes in a csv file and they get a plot. I can get to R fine and get the plot to display through various temp file machinations, but I have hit a roadblock. I cannot figure out how to get R to keep running until the users closes the window. If I plot and exit, the plot disappears immediately. If I plot and use some kind of infinite loop, the user cannot close the plot; he must exit by using an interrupt which I don't like. I see there is a getGraphicsEvent function, but it claims that the device is not supported (X11). Anyway, it doesn't appear to actually support an onClose event, only onMouseDown. Any ideas on how to solve this? edit: Thanks to Dirk for the advice to check out the tk interface. Here is the test code that works: require(tcltk) library(tkrplot) ##function to display plot, called by tkrplot and embedded in a window plotIt<-function(){ plot(x=1:10, y=1:10) } ##create top level window tt<-tktoplevel() ##variable to wait on like a condition variable, to be set by event handler done <- tclVar(0) ##bind to the window destroy event, set done variable when destroyed tkbind(tt,"",function() tclvalue(done) <- 1) ##Have tkrplot embed the plot window, then realize it with tkgrid tkgrid(tkrplot(tt,plotIt)) ##wait until done is true tkwait.variable(done)

  Read the article

• ASP .NET Button event handlers do not fire on the first click, but on the second click after a PostB

  - by John

  Background: I am customizing an existing ASP .NET / C# application. It has it's own little "framework" and conventions for developers to follow when extending/customizing its functionality. I am currently extending some of it's administrative functionality, to which the framework provides a contract to enforce implementation of the GetAdministrationInterface() method, which returns System.Web.UI.Control. This method is called during the Page_Load() method of the page hosting the GUI interface. Problem: I have three buttons in my GUI, each of which have been assigned an Event Handler. My administration GUI loads up perfectly fine, but clicking any of the buttons doesn't do what I expect them to do. However, when I click them a second time, the buttons work. I placed breakpoints at the beginning of each event handler method and stepped through my code. On the first click, none of the event handlers were triggered. On the second click, they fired. Any ideas? Example of Button Definition (within GetAdministrationInterface) public override Control GetAdministrationInterface() { // more code... Button btn = new Button(); btn.Text = "Click Me!"; btn.Click += new EventHandler(Btn_Click); // more code... } Example of Event Handler Method Definition void Btn_Click(object sender, EventArgs e) { // Do Something } Page_Load Method that calls GetAdministrationInterface protected void Page_Load(object sender, System.EventArgs e) { if (!Page.IsAsync) { List<AdministrationInterface> interfaces = <DATABASE CALL>; foreach(AdministrationInteface ai in interfaces) { placeholderDiv.Controls.Add(ai.GetAdministrationInterface()); } } }

  Read the article

• Compile for mixed platform (32, 64) and reference a 32 or 64 bit DLL resolved at runtime

  - by Nigel Aston

  Using VS2010 under windows 32 or 64 bit. Our C# app calls a 3rd party DLL (managed) that interfaces to an unmanaged DLL. The 3rd party DLL API appears identical in 32 or 64 bit although underneath it links to a 32 or 64 bit unmanaged DLL. We want our C# app to run on either 32 or 64 bit OS, ideally it will auto detect the OS and load the appropriate 32rd party DLL - via a simple factory class which tests the Enviroment. So the neatest solution would be a runtime folder containing: OurApp.exe 3rdParty32.DLL 3rdPartyUnmanaged32.DLL 3rdParty64.DLL 3rdPartyUnmanaged64.DLL However, the interface for the managed 3rdParty 32 and 64 dll is identical so both cannot be referenced within the same VS2010 project: when adding the second the warning triangle is shown and it does not get referenced. Is my only answer to create two extra library DLL projects to reference the 3rdParty 32 and 64 Dlls? So I would end up with this project arrangement: Project 1: Builds OurApp.exe, dynamically creates an object for project2 or project3. Project 2: Builds OurApp32.DLL which references 3rdParty32.dll Project 3: Builds OurApp64.DLL which references 3rdParty64.dll

  Read the article

• Move to php in windows? Concern, hints, "please don't do!"?

  - by Daniel

  I am considering to move frome Microsoft languages to PHP (just for web dev) which has quite an interesting syntax, a perlish look (but a wider programmer base) and it allows me to reuse the web without reinventing it. I have some concerns too. I would be more than happy to gather some wisdom from stackoverflow community, (challenge to my opinions warmly welcome). Here are my doubts. Efficiency. Cgi are slow, what I am supposed to use? Fastcgi? Or what else? Efficiency + stability. Is PHP on windows really stable and a good choice in terms of performances? Database. I use very often MSSQL (I regret, i like it). Could I widely and efficiently interface PHP with MSSQL (using smartly stored pro, for example). XSLT + XML performance. I work quite a lot with XML and XSLT and I really find the MS xml parser a great software component. Are parser used in PHP fast, reliable and efficient (I am interested mainly in DOM, not SAX)? Objects. Is the PHP object programming model valid end efficient? 6 Regex. How efficient is PHP processing regexp? Many thanks for your advices.

  Read the article

• Why do I have to specify pure virtual functions in the declaration of a derived class in Visual C++?

  - by neuviemeporte

  Given the base class A and the derived class B: class A { public: virtual void f() = 0; }; class B : public A { public: void g(); }; void B::g() { cout << "Yay!"; } void B::f() { cout << "Argh!"; } I get errors saying that f() is not declared in B while trying do define void B::f(). Do I have to declare f() explicitly in B? I think that if the interface changes I shouldn't have to correct the declarations in every single class deriving from it. Is there no way for B to get all the virtual functions' declarations from A automatically? EDIT: I found an article that says the inheritance of pure virtual functions is dependent on the compiler: http://www.objectmentor.com/resources/articles/abcpvf.pdf I'm using VC++2008, wonder if there's an option for this.

  Read the article

• Zend Framework Application: module dependencies

  - by takeshin

  How do you handle dependencies between modules in Zend Framework to create reusable, drop-in modules? E.g. I have Newsletter module, which allows users to subscribe, providing e-mail address. Next, I plan to add Blog module, which allows to subscribe to posts by e-mail (it obviously duplicates some functionality of the newsletter, but the e-mails addresses are stored in User model). Next one is the Forum module, with the same subscribe to post functionality. But I want to have ability to use these modules independent to each one, i.e. application with newsletter alone, newsletter with blog, comibnation two or three modules at once. This is pretty common, e.g. the same story with search feature. I want to have search module, with options to search in all data, blog data or forum data if available. Is there any design pattern for this? Do I have to add some moduleExists($moduleMame), or provide some interface or abstract classes, some base controller pattern, similar for each module?

  Read the article

• Approach for caching data from data logger

  - by filip-fku

  Greetings, I've been working on a C#.NET app that interacts with a data logger. The user can query and obtain logs for a specified time period, and view plots of the data. Typically a new data log is created every minute and stores a measurement for a few parameters. To get meaningful information out of the logger, a reasonable number of logs need to be acquired - data for at least a few days. The hardware interface is a UART to USB module on the device, which restricts transfers to a maximum of about 30 logs/second. This becomes quite slow when reading in the data acquired over a number of days/weeks. What I would like to do is improve the perceived performance for the user. I realize that with the hardware speed limitation the user will have to wait for the full download cycle at least the first time they acquire a larger set of data. My goal is to cache all data seen by the app, so that it can be obtained faster if ever requested again. The approach I have been considering is to use a light database, like SqlServerCe, that can store the data logs as they are received. I am then hoping to first search the cache prior to querying a device for logs. The cache would be updated with any logs obtained by the request that were not already cached. Finally my question - would you consider this to be a good approach? Are there any better alternatives you can think of? I've tried to search SO and Google for reinforcement of the idea, but I mostly run into discussions of web request/content caching. Thanks for any feedback!

  Read the article

• Nested functions not allowed in drawrect problem

  - by Martin

  I have a custom view onto which I draw some graphics from the drawrect function, which works fine. However I like to draw based on the contens of an array I pass on the the view just before I do a setNeedsDisplay. In the drawRect function I try to access the array but then I get a nested functions error which I do not understand. Here's my code: // // MyView.h // window // #import <UIKit/UIKit.h> @interface MyView : UIView { NSArray * nary; } @property (nonatomic, copy) NSArray *nary; @end // // MyView.m // window // #import "MyView.h" @implementation MyView @synthesize nary; CGContextRef c; CGFloat black[4] = {0.0f, 0.0f, 0.0f, 1.0f}; - (id)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) { // Initialization code } return self; } - (void)drawRect:(CGRect)rect { c = UIGraphicsGetCurrentContext(); CGContextSetStrokeColor(c, black); NSLog(@"mview"); NSArray *ns = [nary objectAtIndex:0]; } - (void)dealloc { [super dealloc]; } @end

  Read the article

• Closing Windows Forms on a Touchscreen

  - by drharris

  Our clients have fat fingers, and so do we. We take touchscreen netbooks apart to insert them into our custom hardware, and I write a software interface that shows up on the touchscreen. The problem is that it has about a 3/4" bezel over the screen, which means hitting that little red "X" becomes a challenge, especially considering reduced capacitive ability on the edges and corners. Is there a way to make this standard close button larger? Of course in the application I can always make really nice 80x80 buttons that are perfectly usable, but there seems to be no way to override the default frame of the form. We have tried enabling Large Fonts and all the built-in accessibility features, but nothing seems to make it large enough to hit successfully. Simply adding a toolbar button is also not much of an option. We prefer to utilize the standard look and feel of a normal Windows application. Alternatively, should we be looking at making some sort of "kiosk mode" where we simply go fullscreen and do nothing involving the taskbar or title bar? How difficult is this to accomplish, if so?

  Read the article

• GetIpAddrTable() leaks memory. How to resolve that?

  - by Stabledog

  On my Windows 7 box, this simple program causes the memory use of the application to creep up continuously, with no upper bound. I've stripped out everything non-essential, and it seems clear that the culprit is the Microsoft Iphlpapi function "GetIpAddrTable()". On each call, it leaks some memory. In a loop (e.g. checking for changes to the network interface list), it is unsustainable. There seems to be no async notification API which could do this job, so now I'm faced with possibly having to isolate this logic into a separate process and recycle the process periodically -- an ugly solution. Any ideas? // IphlpLeak.cpp - demonstrates that GetIpAddrTable leaks memory internally: run this and watch // the memory use of the app climb up continuously with no upper bound. #include <stdio.h> #include <windows.h> #include <assert.h> #include <Iphlpapi.h> #pragma comment(lib,"Iphlpapi.lib") void testLeak() { static unsigned char buf[16384]; DWORD dwSize(sizeof(buf)); if (GetIpAddrTable((PMIB_IPADDRTABLE)buf, &dwSize, false) == ERROR_INSUFFICIENT_BUFFER) { assert(0); // we never hit this branch. return; } } int main(int argc, char* argv[]) { for ( int i = 0; true; i++ ) { testLeak(); printf("i=%d\n",i); Sleep(1000); } return 0; }

  Read the article

• .NET binary serialization conditionally without ISerializable

  - by SillyWhy

  I got 2 classes, for example: public class A { private B b; ... } public class B { ... } I need to serialize an object A using BinaryFormatter. When remoting it shall include the field b, but not when serialize to file. Here is what I added: [Serializable] public class A : MarshalByRefObject { private B b; [OnSerializing] private void OnSerializing(StreamingContext context) { if (context.State == StreamingContextStates.File) { this.b = null; } } ... } [Serializable] public class B : MarshalByRefObject { ... } I think this is a bad design because if another class C also contains B, in class C we must add the duplicate OnSerializing() logic as in A. Class B should decide what to do, not class A or C. I don't want to use ISerializable interface because there are too many variables in class B have to be added to SerializationInfo. I can create a SerializationSurrogate for class B, which perform nothing in GetObjectData() & SetObjectData(), then use it when serializing to file. However the same maintenance issue because whoever modify class B can't notice what going to happen during serialization & the existence of SerializationSurrogate. Is there a better alternative?

  Read the article

• Toolbox/framework to construct lightweight public-facing web site

  - by aSteve

  I am aware of full-blown content management systems (CMS) such as SugarCRM and TikiWiki... where content is typically stored in a database... and edited through the same interface as it is published. While I like many of the features, the product is clearly aimed at enterprise-wide use rather than to be public-facing. What I'd like to establish are potential alternatives that fill the space between full-blown CMS and hand-coded bespoke site. I like the way that I can add modules to my CMS... allowing me to quickly introduce new functionality, and I'd like an analogous feature in a system for public web-content. Modules I know I'd like include moderated comments; web-form-to-email gateway; menus/tabs... in future, perhaps mapping or diaries or RSS integration - etc. Where my requirements differ from a CMS, I don't need (or want) most content to be editable through the main site... and, somehow, I do want to be able to preview how updates will be presented to the public rather than to make live changes. For these purposes, in contrast to those where a typical CMS would be ideal, presentation is of paramount importance - and trumps any desire to immediately disseminate information. I realise that this is a very high-level question... (suggestions of additional tags welcome) - I mentioned PHP only as - ideally - I'm looking for an open source solution and a PHP deployment is an easy option. What are my options?

  Read the article

• "Detecting" and loading of "plugins" in GAE

  - by Patrick Cornelissen

  Hi! I have a "plugin like" architecture and I want to create one instance of each class that implements a dedicated interface and put these in a cache. (To have a singleton-ish effect). The plugins will be provided as jars and put into the app engine war file before the app is uploaded. I have tried to use the ClassPathScanningCandidateComponentProvider as I'm using spring anyway, but this didn't work. The provider complained that it was not able to find the HttpServletResponse class file while scanning the classpath. I can't get around this, when I add the servlet jar, then I'll get of course problems, because the same jar is also provided by the GAE. If I don't, I'm getting the error above... So I tried to add a static initialization code, but of course this doesn't work, because the class is initialized when it's instantiated for the first time. (Well I knew that but it was worth a try) The last chance I currently see is that I create a properties file with all plugin classes when the package is created, but this requires writing of a maven plugin etc. and I'd like to avoid that. Is there something that I am missing?

  Read the article

• fetching the label text from database in C#

  - by Yilmaz Paçariz

  private void button5_Click(object sender, EventArgs e) { SqlConnection conn = new SqlConnection("Data Source=MAZI-PC\\PROJECTACC;Initial Catalog=programDB;Integrated Security=True"); SqlCommand cmd = new SqlCommand("select label_sh from label_text where label_form='2' and label_form_labelID='1'", conn); conn.Open(); label1.Text = cmd.ExecuteReader().ToString(); conn.Close(); SqlConnection conn1 = new SqlConnection("Data Source=MAZI-PC\\PROJECTACC;Initial Catalog=programDB;Integrated Security=True"); SqlCommand cmd1 = new SqlCommand("select label_sh from label_text where label_form='2' and label_form_labelID='2'", conn1); conn1.Open(); label2.Text = cmd1.ExecuteReader().ToString(); conn1.Close(); SqlConnection conn2 = new SqlConnection("Data Source=MAZI-PC\\PROJECTACC;Initial Catalog=programDB;Integrated Security=True"); SqlCommand cmd2 = new SqlCommand("select label_sh from label_text where label_form='2' and label_form_labelID='3'", conn2); conn2.Open(); label3.Text = cmd2.ExecuteReader().ToString(); conn2.Close(); } I am developing a small project in C#... Using Visiual Studio 2010... I want to fetch the label texts from database in order to change the user interface language with a button... I wrote this code but there is a problem in SQLDATAREADER in label text parts it shows System.Data.SqlClient.SqlDataReader I cant fix, could you help me?

  Read the article

• "|" pipe operator not working in command line in C++

  - by user332024

  I am having a windows application interacting with DB2 database. In my application i have code to execute some DB2 commands through command line interface. I have used windowsAPI "ShellExecuteEx()" to execute those DB2 commands through command line. Following is the code written to execute DB2 command through command line. string command = "/c /w /i DB2 UNCATALOG NODE DB_DATABASE "" test.log | echo %date% %time% test.log SHELLEXECUTEINFO shellInfo; ZeroMemory(&shellInfo, sizeof(shellInfo)); shellInfo.cbSize = sizeof(shellInfo); shellInfo.fMask = SEE_MASK_FLAG_NO_UI | SEE_MASK_NOCLOSEPROCESS; //shellInfo.lpFile = "db2cmd"; shellInfo.lpFile = "db2cmd"; shellInfo.lpParameters = command.c_str(); The code is executed successfully , however if test.log is observered i only get result of DB2 command and not date and time. If you see the above command there is "|" pipe operator and echo command to log date and time in test.log Please note that if I execute above DB2 command through separately command line i.e. not through code. I am able to view date and time log along with DB2 command result in test.log. Following is the full command which i executed through command line. DB2CMD /c /i /w DB2 UNCATALOG NODE DB_DATABASE "" test.log | echo %date% %time% test.log According to me since DB2 command is executed successfully through code, there is problem with only usage of "|" pipe operator or echo command.

  Read the article

• JPA returning null for deleted items from a set

  - by Jon

  This may be related to my question from a few days ago, but I'm not even sure how to explain this part. (It's an entirely different parent-child relationship.) In my interface, I have a set of attributes (Attribute) and valid values (ValidValue) for each one in a one-to-many relationship. In the Spring MVC frontend, I have a page for an administrator to edit these values. Once it's submitted, if any of these fields (as <input> tags) are blank, I remove the ValidValue object like so: Set<ValidValue> existingValues = new HashSet<ValidValue>(attribute.getValidValues()); Set<ValidValue> finalValues = new HashSet<ValidValue>(); for(ValidValue validValue : attribute.getValidValues()) { if(!validValue.getValue().isEmpty()) { finalValues.add(validValue); } } existingValues.removeAll(finalValues); for(ValidValue removedValue : existingValues) { getApplicationDataService().removeValidValue(removedValue); } attribute.setValidValues(finalValues); getApplicationDataService().modifyAttribute(attribute); The problem is that while the database is updated appropriately, the next time I query for the Attribute objects, they're returned with an extra entry in their ValidValue set -- a null, and thus, the next time I iterate through the values to display, it shows an extra blank value in the middle. I've confirmed that this happens at the point of a merge or find, at the point of "Execute query ReadObjectQuery(entity.Attribute). Here's the code I'm using to modify the database (in the ApplicationDataService): public void modifyAttribute(Attribute attribute) { getJpaTemplate().merge(attribute); } public void removeValidValue(ValidValue removedValue) { ValidValue merged = getJpaTemplate().merge(removedValue); getJpaTemplate().remove(merged); } Here are the relevant parts of the entity classes: Entity @Table(name = "attribute") public class Attribute { @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "attribute") private Set<ValidValue> validValues = new HashSet<ValidValue>(0); } @Entity @Table(name = "valid_value") public class ValidValue { @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "attr_id", nullable = false) private Attribute attribute; }

  Read the article

• JSR-299 (CDI) configuration at runtime

  - by nsn

  I need to configure different @Alternatives, @Decorators and @Injectors for different runtime environments (think testing, staging and production servers). Right now I use maven to create three wars, and the only difference between those wars are in the beans.xml files. Is there a better way to do this? I do have @Alternative @Stereotypes for the different environments, but even then I need to alter beans.xml, and they don't work for @Decorators (or do they?) Is it somehow possible to instruct CDI to ignore the values in beans.xml and use a custom configuration source? Because then I could for example read a system property or other environment variable. The application exclusively runs in containers that use Weld, so a weld-specific solution would be ok. I already tried to google this but can't seem to find good search terms, and I asked the Weld-Users-Forums, but to no avail. Someone over there suggested to write my own custom extension, but I can't find any API to actually change the container configuration at runtime. I think it would be possible to have some sort of @ApplicationScoped configuration bean and inject that into all @Decorators which could then decide themselves whether they should be active or not and then in order to configure @Alternatives write @Produces methods for every interface with multiple implementations and inject the config bean there too. But this seems to me like a lot of unnecessary work to essentially duplicate functionality already present in CDI?

  Read the article

• Looking for Simplified Overview of EJB3

  - by sdoca

  Hi I'm looking for a simplified overview of EJB3 components. I seem to understand most of the pieces of the puzzle, but can't quite get them to fit together in my brain as a full picture. I've developed numerous web applications (wars) that have been deployed on Tomcat before, but not a full-fledged EE application (ear). I would like the overview to be as generic as possible. I'm not looking for a tutorial on how to set up EJB3 on Glassfish built in NetBeans or some other vendor specific tutorial that's more about the IDE than the technology. I keep reading about Java, ejb-jar, web and ear modules but am not clear on what these different modules contain and how to use them to put together my app. In my case, I want to write a simple database CRUD web application. The first step is simple; create entity classes that model the database tables my app will be using. I plan on using annotations. Should I create a jar that contains just these enity classes? Is this the ejb-jar module (sometimes referred to as the Java module)? Next, I'll need some business logic classes that make use of the entity classes. These are the session beans (stateless or stateful) correct? Should these be packaged in the same jar as the entity classes or a separate jar? Finally, I'll need some sort of web interface (I'll be creating a JSF portlet) application that makes use of the both the session and entity beans. Together with the above jar(s), this will be my war? Assuming the above to be correct, what is involved in creating an ear? Forgive me if this post is vague, but I'm having a hard time defining what it is I don't understand. Thanks for any help!

  Read the article

• J2EE and alternatives

  - by Ilya K

  Hello, I am J2SE developer but I have rich web-background (php, perl/cgi and so on) and now I am starting new project. It will have web interface, spaghetti business logic, relational database as storage and connections to other services. I do it from the scratch. My colleagues told me to use spring, spring security and struts. I look briefly at J2EE spec and found that it covers almost all aspects of enterprise application. I asked my colleagues why do they need spring and struts, but looks like they use technologies simply because they are familiar with them and not familiar with classic J2EE stack. So, my question is: what is bad about J2EE? Why do I need spring if there are JNDI lookups? It will take a day or two to create fake InitialContext for unit-tests. And that is all: I stand with out of external tools like spring. Why do I need spring-security if there is a security built in Servlets spec? I can map any request to any servlet using web.xml, no struts.xml is needed. I can use servlet-filters instead of struts interceptors. There is RMI, so I do not need spring-remote. And so on.. Why should I bother my self with all that fancy stuff if there is J2EE? I really want to find situation when J2EE is not enough. Do you have any? Thanks!

  Read the article

• Which is the correct design pattern for my PHP application?

  - by user1487141

  I've been struggling to find good way to implement my system which essentially matches the season and episode number of a show from a string, you can see the current working code here: https://github.com/huddy/tvfilename I'm currently rewriting this library and want a nicer way to implement how the the match happens, currently essentially the way it works is: There's a folder with classes in it (called handlers), every handler is a class that implements an interface to ensure a method called match(); exists, this match method uses the regex stored in a property of that handler class (of which there are many) to try and match a season and episode. The class loads all of these handlers by instantiating each one into a array stored in a property, when I want to try and match some strings the method iterates over these objects calling match(); and the first one that returns true is then returned in a result set with the season and episode it matched. I don't really like this way of doing it, it's kind of hacky to me, and I'm hoping a design pattern can help, my ultimate goal is to do this using best practices and I wondered which one I should use? The other problems that exist are: More than one handler could match a string, so they have to be in an order to prevent the more greedy ones matching first, not sure if this is solvable as some of the regex patterns have to be greedy, but possibly a score system, something that shows a percentage of how likely the match is correct, i'd have no idea how to actually implement this though. I'm not if instantiating all those handlers is a good way of doing it, speed is important, but using best practices and sticking to design patterns to create good, extensible and maintainable code is my ultimate priority. It's worth noting the handler classes sometimes do other things than just regex matching, they sometimes prep the string to be matched by removing common words etc. Cheers for any help Billy

  Read the article

• OrderBy Linq.Expression as parameter = (Of Func(Of T,IComparable)) to perform LinqToEntity is not working

  - by NicoJuicy

  I'd like to get this working: Call: (Count & Page are used for pagination, so Count = 20 and Page = 1 for example, for the first 20 values). Sorting should be by name LeverancierService.GetLeveranciers(Function(el) el.Name, Count, Page) Equivalent in c#: LeverancierService.GetLeveranciers(el= el.Name, Count, Page) Method that gives an error (parameters shown above): Public Overridable Function GetAllPaged(orderby As Expression(Of Func(Of T, IComparable)), ByVal Count As Integer, ByVal Page As Integer) As IEnumerable(Of T) Return dbset.OrderBy(orderby).Skip((Page - 1) * Count).Take(Count).ToList() End Function Already tried changing it to this, but it gives the same error: Public Overridable Function GetAllPaged(Of TOrderBy)(orderby As Expression(Of Func(Of T, TOrderBy)), ByVal Count As Integer, ByVal Page As Integer) As IEnumerable(Of T) Return dbset.OrderBy(orderby).Skip((Page - 1) * Count).Take(Count).ToList() End Function Error: Unable to cast the type 'System.String' to type 'System.IComparable'. LINQ to Entities only supports casting Entity Data Model primitive types. Any idea how to do this? Extra info: I'm in a DDD-layered application, so the parameter should stay the same as the called method is an overridden interface (eg. if i change this, i have to do this for 200 times or so, because it's in VB.Net and not in C# (= 1 change) ) I know there is a way to change the expression to a string and then use DLinq (= Dynamic Linq), but that's not how it should be.

  Read the article

• How do I call +class methods in Objective C without referencing the class?

  - by TimM

  I have a series of "policy" objects which I thought would be convenient to implement as class methods on a set of policy classes. I have specified a protocol for this, and created classes to conform to (just one shown below) @protocol Counter +(NSInteger) countFor: (Model *)model; @end @interface CurrentListCounter : NSObject <Counter> +(NSInteger) countFor: (Model *)model; @end I then have an array of the classes that conform to this protocol (like CurrentListCounter does) +(NSArray *) availableCounters { return [[[NSArray alloc] initWithObjects: [CurrentListCounter class],[AllListsCounter class], nil] autorelease]; } Notice how I am using the classes like objects (and this might be my problem - in Smalltalk classes are objects like everything else - I'm not sure if they are in Objective-C?) My exact problem is when I want to call the method when I take one of the policy objects out of the array: id<Counter> counter = [[MyModel availableCounters] objectAtIndex: self.index]; return [counter countFor: self]; I get a warning on the return statement - it says -countFor: not found in protocol (so its assuming its an instance method where I want to call a class method). However as the objects in my array are instances of class, they are now like instance methods (or conceptually they should be). Is there a magic way to call class methods? Or is this just a bad idea and I should just create instances of my policy objects (and not use class methods)?

  Read the article

• Basic SWIG C++ use for Java

  - by duckworthd

  I've programmed a couple years in both C++ and Java, but I've finally come to a point where I need to bring a little unification between the two -- ideally, using SWIG. I've written a tiny and fairly pointless little class called Example: #include <stdio.h> class Example { public: Example(); ~Example(); int test(); }; #include "example.h" Example::Example() { printf("Example constructor called\n"); } Example::~Example() { printf("Example destructor called\n"); } int Example::test() { printf("Holy sh*t, I work!\n"); return 42; } And a corresponding interface file: /* File: example.i */ %module test %{ #include "example.h" %} %include "example.h" Now I have questions. Firstly, when I want to actually run SWIG initially, am I supposed to use the example_wrap.c (from swig -java example.i) or example_wrap.cxx (from swig -c++ example.i) file when recompiling with my original example.cpp? Or perhaps both? I tried both and the latter seemed most likely, but when I recompile as so: g++ example.cpp example_wrap.cxx -I/usr/lib/jvm/java-6-sun-.../include/ I get a host of errors regarding TcL of all things, asking me for the tcl.h header. I can't even wrap my mind around why it wants that much less needs it, and as such have found myself where I don't even know how to begin using SWIG.

  Read the article

• Efficient database access when dealing with multiple abstracted repositories

  - by Nathan Ridley

  I want to know how most people are dealing with the repository pattern when it involves hitting the same database multiple times (sometimes transactionally) and trying to do so efficiently while maintaining database agnosticism and using multiple repositories together. Let's say we have repositories for three different entities; Widget, Thing and Whatsit. Each repository is abstracted via a base interface as per normal decoupling design processes. The base interfaces would then be IWidgetRepository, IThingRepository and IWhatsitRepository. Now we have our business layer or equivalent (whatever you want to call it). In this layer we have classes that access the various repositories. Often the methods in these classes need to do batch/combined operations where multiple repositories are involved. Sometimes one method may make use of another method internally, while that method can still be called independently. What about, in this scenario, when the operation needs to be transactional? Example: class Bob { private IWidgetRepository _widgetRepo; private IThingRepository _thingRepo; private IWhatsitRepository _whatsitRepo; public Bob(IWidgetRepository widgetRepo, IThingRepository thingRepo, IWhatsitRepository whatsitRepo) { _widgetRepo = widgetRepo; _thingRepo= thingRepo; _whatsitRepo= whatsitRepo; } public void DoStuff() { _widgetRepo.StoreSomeStuff(); _thingRepo.ReadSomeStuff(); _whatsitRepo.SaveSomething(); } public void DoOtherThing() { _widgetRepo.UpdateSomething(); DoStuff(); } } How do I keep my access to that database efficient and not have a constant stream of open-close-open-close on connections and inadvertent invocation of MSDTS and whatnot? If my database is something like SQLite, standard mechanisms like creating nested transactions are going to inherently fail, yet the business layer should not have to be concerning itself with such things. How do you handle such issues? Does ADO.Net provide simple mechanisms to handle this or do most people end up wrapping their own custom bits of code around ADO.Net to solve these types of problems?

  Read the article

< Previous Page | 498 499 500 501 502 503 504 505 506 507 508 509  | Next Page >