Search Results

Search found 9335 results on 374 pages for 'random thoughts'.

Page 297/374 | < Previous Page | 293 294 295 296 297 298 299 300 301 302 303 304  | Next Page >

  • What issues to consider when rolling your own data-backend for Silverlight / AJAX on non-ASP.NET ser

    - by Edward Tanguay
    I have read-only Silverlight and AJAX apps which read static text and XML files from a PHP/Apache server, which works very nicely with features such as asynchronous loading, lazy-loading only what I need for each page, loading in the background, developed a little query language to get a PHP script to create custom XML files etc. it's pragmatic read-only REST, and all works fast and fine for read-only sites. Now I want to also add the ability to write data from these apps to a database on the same PHP/Apache server. For those of you who have built similar data-access layers, what do I need to consider while building this, especially regarding security so that not just any client can write and alter my database, e.g.: check HTTP_USER_AGENT for security check REMOTE_ADDR for security require a special code for security, perhaps a list of TAN codes (such as banks use for online transactions) each which can only be used once, both the client and server have these I wonder if there is some kind of standard REST query I should lean on for e.g. building SQL-like statements in the URL parameters, e.g. http://www.thedatalayersite.com/query?insertinto=customers&... Any thoughts, notes from experience, ideas, gotchas, especially ideas on tightening down security in this endeavor would be helpful.

    Read the article

  • ASP.NET MVC intermittent slow response

    - by arehman
    Problem In our production environment, system occasionally delays the page response of an ASP.NET MVC application up to 30 seconds or so, even though same page renders in 2-3 seconds most of the times. This happens randomly with any arbitrary page, and GET or POST type requests. For example, log files indicates, system took 15 seconds to complete a request for jquery script file or for other small css file it took 10 secs. Similar Problems: Random Slow Downs Production Environment: Windows Server 2008 - Standard (32-bit) - App Pool running in integrated mode. ASP.NET MVC 1.0 We have tried followings/observations: Moved the application to a stand alone web server, but, it didn't help. We didn't ever notice same issue on the server for any 'ASP.NET' application. App Pool settings are fine. No abrupt recycles/shutdowns. No cpu spikes or memory problems. No delays due to SQL queries or so. It seems as something causing delay along HTTP Pipeline or worker processor seeing the request late. Looking for other suggestions. -- Thanks

    Read the article

  • Most efficient way to send images across processes

    - by Heinrich Ulbricht
    Goal Pass images generated by one process efficiently and at very high speed to another process. The two processes run on the same machine and on the same desktop. The operating system may be WinXP, Vista and Win7. Detailled description The first process is solely for controlling the communication with a device which produces the images. These images are about 500x300px in size and may be updated up to several hundred times per second. The second process needs these images to display them. The first process uses a third party API to paint the images from the device to a HDC. This HDC has to be provided by me. Note: There is already a connection open between the two processes. They are communicating via anonymous pipes and share memory mapped file views. Thoughts How would I achieve this goal with as little work as possible? And I mean both work for me and the computer. I am using Delphi, so maybe there is some component available for doing this? I think I could always paint to any image component's HDC, save the content to memory stream, copy the contents via the memory mapped file, unpack it on the other side and paint it there to the destination HDC. I also read about a IPicture interface which can be used to marshall images. What are your ideas? I appreciate every thought on this!

    Read the article

  • Restrict access to connection pool in Weblogic?

    - by Andrew White
    In short, how can I restrict access to connection pool X based on application name or JAR name? A simple use case might help... A business web-app (call it WEB_APP_A) uses pool Y to do basic look-up SQL. Some users of this web-app have access to also update some sensitive data in the database. This code is provided by a JAR file (call it HR_JAR) that can be dropped in where needed. This JAR uses pool X for all of it's connections. We don't want developers of WEB_APP_A using pool X. We only want HR_JAR using pool X. This is to keep devs of WEB_APP_A from accidentally or intentionally abusing the access pool X provides. Some considerations: This is legacy code so HR_JAR is here to stay We are running on Weblogic 9.2 We can not keep passwords in any from in the source code We have researched weblogic user level authn/authz for JDBC resources but then this begs the question; how do we secure the user creds we use to become a user per app/jar? Ideas? Thoughts? I can elaborate more on what I have tried, but I wanted fresh ideas.

    Read the article

  • Telerik vs. Infragistics for Silverlight

    - by JeffN825
    Yes, this is certainly a duplicate question, but I wanted to get some fresh takes. My impression is that Telerik is a much more complete suite, but I'm really really turned off by the responsiveness of their controls. It just seems "clunky" in terms of responsiveness (I have a very fast computer and video card). Scrolling in a grid and transitions chunk, even in their latest demos where they claim to have good performance. I do like that their WPF suite matches their SL one in terms of API. Infragistics has fewer controls and less theming possibilities, but their controls are very responsive. Scrolling in a grid is fluid, as are their combo menus and all the other controls. I checked out ComponentOne and their controls seem analogous to Telerik's in terms of the points mentioned above but are a little less "pretty". Any thoughts from other users of these suites? Basically, what I'm looking for is a suite that will be highly performant and responsive, relatively customizable from a theming standpoint, and have enough functionality to develop a LOB SL application without having to use multiple suites to satisfy the majority of common requirements.

    Read the article

  • ObjectDataSource.Select with Parameters Time Out

    - by MasterMax1313
    I'm using an ObjectDataSource with a 2008 ReportViewer control and Linq to CSV. The ODS has two parameters (the SQL is spelled out in an XSD file with a table adapter). The Reportviewer takes a very long time to render the output after a button is clicked to generate the report. That's my first problem. Even though it works (most of the time), the processing time worries me, and subsequent requests don't seem to be changing the results shown on the screen. The next issue is that when I go to export the ODS to CSV I'm getting a time out exception on the select method of the ODS (shown below). This works for ODS without parameters, but it seems like now that I've added parameters that it doesn't want to cooperate. I'm fresh out of ideas, any thoughts? <asp:ObjectDataSource ID="obsGetDataAllCustomers" runat="server" SelectMethod="GetDataAllCustomers" TypeName="my.myAdapter.AllCustomers" OldValuesParameterFormatString="original_{0}" > <SelectParameters> <asp:ControlParameter ControlID="StartDate" Name="Start" PropertyName="Text" Type="DateTime" /> <asp:ControlParameter ControlID="EndDate" Name="_End" PropertyName="Text" Type="DateTime" /> </SelectParameters> </asp:ObjectDataSource> After button click to view report - rvAllCustomers.LocalReport.Refresh() Export to CSV (adding the items returned to a list which is then processed by working code) - For Each dr As DataRow In CType(obs.Select(), DataView).Table.Rows l.Add(New FullOrderOutput(dr)) Next

    Read the article

  • event flow in action script 3

    - by Shay
    i try to dispatch a custom event from some component on the stage and i register other component to listen to it but the other component doesn't get the event here is my code what do i miss public class Main extends MovieClip //main document class { var compSource:Game; var compMenu:Menu; public function Main() { compSource = new Game; compMenu = new Menu(); var mc:MovieClip = new MovieClip(); addChild(mc); mc.addChild(compSource); // the source of the event - event dispatch when clicked btn mc.addChild(compMenu); //in init of that Movie clip it add listener to the compSource events } } public class Game extends MovieClip { public function Game() { btn.addEventListener(MouseEvent.CLICK, onFinishGame); } private function onFinishGame(e:MouseEvent):void { var score:Number = Math.random() * 100 + 1; dispatchEvent(new ScoreChanged(score)); } } public class Menu extends MovieClip { //TextField score public function Menu() { addEventListener(Event.ADDED_TO_STAGE, init); } private function init(e:Event):void { removeEventListener(Event.ADDED_TO_STAGE, init); //on init add listener to event ScoreChanged addEventListener(ScoreChanged.SCORE_GAIN, updateScore); } public function updateScore(e:ScoreChanged):void { //it never gets here! tScore.text = String(e._score); } } public class ScoreChanged extends Event { public static const SCORE_GAIN:String = "SCORE_GAIN"; public var _score:Number; public function ScoreChanged( score:Number ) { trace("new score"); super( SCORE_GAIN, true); _score = score; } } I don't want to write in Main compSource.addEventListener(ScoreChanged.SCORE_GAIN, compMenu.updateScore); cause i dont want the the compSource will need to know about compMenu its compMenu responsibility to know to what events it needs to listen.... any suggestions? Thanks!

    Read the article

  • Graph-structured databases and Php

    - by stagas
    I want to use a graph database using php. Can you point out some resources on where to get started? Is there any example code / tutorial out there? Or are there any other methods of storing data that relate to each other in totally random/abstract situations? - Very abstract example of the relations needed: John relates to Mary, both relate to School, John is Tall, Mary is Short, John has Blue Eyes, Mary has Green Eyes, query I want is which people are related to 'Short people that have Green Eyes and go to School' - answer John - Another example: TrackA -> ArtistA -> ArtistB -> AlbumA -----> [ label ] -> AlbumB -----> [ A ] -> TrackA:Remix -> Genre:House -> [ Album ] -----> [ label ] TrackB -> [ C ] [ B ] Example queries: Which Genre is TrackB closer to? answer: House - because it's related to Album C, which is related to TrackA and is related to Genre:House Get all Genre:House related albums of Label A : result: AlbumA, AlbumB - because they both have TrackA which is related to Genre:House - It is possible in MySQL but it would require a fixed set of attributes/columns for each item and a complex non-flexible query, instead I need every attribute to be an item by itself and instead of 'belonging' to something, to be 'related' to something.

    Read the article

  • Iterator performance contract (and use on non-collections)

    - by polygenelubricants
    If all that you're doing is a simple one-pass iteration (i.e. only hasNext() and next(), no remove()), are you guaranteed linear time performance and/or amortized constant cost per operation? Is this specified in the Iterator contract anywhere? Are there data structures/Java Collection which cannot be iterated in linear time? java.util.Scanner implements Iterator<String>. A Scanner is hardly a data structure (e.g. remove() makes absolutely no sense). Is this considered a design blunder? Is something like PrimeGenerator implements Iterator<Integer> considered bad design, or is this exactly what Iterator is for? (hasNext() always returns true, next() computes the next number on demand, remove() makes no sense). Similarly, would it have made sense for java.util.Random implements Iterator<Double>? Should a type really implement Iterator if it's effectively only using one-third of its API? (i.e. no remove(), always hasNext())

    Read the article

  • client-server syncing methodology [theoretical]

    - by Kenneth Ballenegger
    I'm in the progress of building an web-app that syncs with an iOS client. I'm currently tackling trying to figure out how to go about about syncing. I've come up with following two directions: I've got a fairly simple server web-app with a list of items. They are ordered by date modified and as such syncing the order does not matter. One direction I'm considering is to let the client deal with syncing. I've already got an API that lets the client get the data, as well as do certain actions on it, such as update, add or remove single items. I was considering: 1) on each sync asking the server for all items modified since the last successful sync and updating the local records based on what's returned by the server, and 2) building a persistent queue of create / remove / update requests on the client, and keeping them until confirmation by the server. The risk with this approach is that I'm basically asking each side to send changes to the other side, hoping it works smoothly, but risking a diversion at some point. This would probably be more bandwidth-efficient, though. The other direction I was considering was a more traditional model. I would have a "sync" process in which the client would send its whole list to the server (or a subset since last modified sync), the server would update the data on the server (by fixing conflicts by keeping the last modified item, and keeping deleted items with a deleted = 1 field), and the server would return an updated list of items (since last successful sync) which the client would then replace its data with. Thoughts?

    Read the article

  • storing/retrieving data for graph with long continuous stretches

    - by james
    i have a large 2-dimensional data set which i would like to graph. the graph is displayed in a browser and the data is retrieved via ajax. long stretches of this graph will be continuous - e.g., for x=0 through x=1000, y=9, then for x=1001 through x=1100, y=80, etc. the approach i'm considering is to send (from the server) and store (in the browser) only the points where the data changes. so for the example above, i would say data[0] = 9, then data[1001] = 80. then given x=999 for example, retrieving data[999] would actually look up data[0]. the problem that arises is finding a dictionary-like data structure which behaves like this. the approach i'm considering is to store the data in a traditional dictionary object, then also maintain a sorted array of key for that object. when given x=999, it would look at the mid-point of this array, determine whether the nearest lower key is left or right of that midpoint, then repeat with the correct subsection, etc.. does anyone have thoughts on this problem/approach?

    Read the article

  • 32 bit dllimport generating incorrect format error (0x8007000b) on win7 x64 platform

    - by DFP
    Hello, I'm trying to install and run a 32 bit application on a Win7 x64 machine. The application is built as a Win32 app. It runs fine on 32 bit platforms. On the x64 machine it installs correctly in the Programs(x86) directory and runs fine until I make a call into a 32 bit dll. At that time I get the incorrect format error (0x8007000b) indicating it is trying to load the dll of the wrong bitness. Indeed it is trying to load the 64 bit dll from the System32 directory rather than the 32 bit version in the SystemWOW64 directory. Another 32 bit application provided by the dll vendor runs correctly and it does load the 32 bit dll from the SystemWOW64 directory. I do not have source to their application to see how they are accessing the DLL. I'm using the DllImport function as shown below to access the dll. Is there a way to decorate the DllImport calls to force it to load the 32 bit version? Any thoughts appreciated. Thanks, DP public static class Micronas { [DllImport(@"UAC2.DLL")] public static extern short UacBuildDeviceList(uint uFlags); [DllImport(@"UAC2.DLL")] public static extern short UacGetNumberOfDevices(); [DllImport(@"UAC2.DLL")] public static extern uint UacGetFirstDevice(); [DllImport(@"UAC2.DLL")] public static extern uint UacGetNextDevice(uint handle); [DllImport(@"UAC2.DLL")] public static extern uint UacSetXDFP(uint handle, short adr, uint data); [DllImport(@"UAC2.DLL")] public unsafe static extern uint UacGetXDFP(uint handle, short adr, IntPtr data); }

    Read the article

  • What is wrong with this mail header text?

    - by dnagirl
    The following $header is being sent via PHP's mail($to,$subject,$content,$header) command. The mail arrives and appears to have an attachment. But the mail text is empty as is the file. I think this has something to do with line spacing but I can't see the problem. I have tried putting the contents (between the boundaries) in $contents rather than appending it to $header. It doesn't make a difference. Any thoughts? From: [email protected] Reply-To: [email protected] X-Mailer: PHP 5.3.1 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="7425195ade9d89bc7492cf520bf9f33a" --7425195ade9d89bc7492cf520bf9f33a Content-type:text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit this is a test message. --7425195ade9d89bc7492cf520bf9f33a Content-Type: application/pdf; name="test.pdf" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="test.pdf" JVBERi0xLjMKJcfsj6IKNSAwIG9iago8PC9MZW5ndGggNiAwIFIvRmlsdGVyIC9GbGF0ZURlY29k ZT4+CnN0cmVhbQp4nE2PT0vEMBDFadVdO4p/v8AcUyFjMmma5CqIIF5cctt6WnFBqLD1+4Np1nY3 c3lvfm+GyQ4VaUY11iQ2PTyuHG5/Ibdx9fIvhi3swJMZX24c602PTzENegwUbNAO4xcoCsG5xuWE . ... the rest of the file . MDAwMDA2MDYgMDAwMDAgbiAKMDAwMDAwMDcwNyAwMDAwMCBuIAowMDAwMDAxMDY4IDAwMDAwIG4g CjAwMDAwMDA2NDcgMDAwMDAgbiAKMDAwMDAwMDY3NyAwMDAwMCBuIAowMDAwMDAxMjg2IDAwMDAw IG4gCjAwMDAwMDA5MzIgMDAwMDAgbiAKdHJhaWxlcgo8PCAvU2l6ZSAxNCAvUm9vdCAxIDAgUiAv SW5mbyAyIDAgUgovSUQgWzxEMURDN0E2OUUzN0QzNjI1MDUyMEFFMjU0MTMxNTQwQz48RDFEQzdB NjlFMzdEMzYyNTA1MjBBRTI1NDEzMTU0MEM+XQo+PgpzdGFydHhyZWYKNDY5MwolJUVPRgo= --7425195ade9d89bc7492cf520bf9f33a-- $header ends without a line break

    Read the article

  • Problem Parsing JSON Result with jQuery

    - by senfo
    I am attempting to parse JSON using jQuery and I'm running into issues. In the code below, I'm using a static file, but I've also tested using an actual URL. For some reason, the data keeps coming back as null: <!DOCTYPE html> <html> <head> <title>JSON Test</title> <script src="http://code.jquery.com/jquery-latest.js"></script> <script> $.getJSON('results.json', function(data) { alert(data); // Result is always null }); </script> </head> <body> </body> </html> The JSON results look like the following: {"title":"HEALTHPOINT TYEE CAMPUS","link":"http://www.healthpointchc.org","id":"tag:datawarehouse.hrsa.gov,2010-04-29:/8357","org":"HEALTHPOINT TYEE CAMPUS","address":{"street-address":"4424 S. 188TH St.","locality":"Seatac","region":"Washington","postal-code":"98188-5028"},"tel":"206-444-7746","category":"Service Delivery Site","location":"47.4344818181818 -122.277672727273","update":"2010-04-28T00:00:00-05:00"} If I replace my URL with the Flickr API URL (http://api.flickr.com/services/feeds/photos_public.gne?tags=cat&tagmode=any&format=json&jsoncallback=?), I get back a valid JSON result that I am able to make use of. I have successfully validated my JSON at JSONLint, so I've run out of ideas as to what I might be doing wrong. Any thoughts?

    Read the article

  • Autocomplete and IE7 - slowness, sluggishness as overall pagesize grows?

    - by wchrisjohnson
    Hi, I have the autocomplete plugin (http://bassistance.de/jquery-plugins/jquery-plugin-autocomplete/, version 1.1 and 1.0.2) on a project to add pieces of "equipment" to a "project". On a fresh project the plugin works great; the data returned from the database comes back FAST, you can scroll the list fast, and can select an item and move on to the next one. Once I have a project established with equipment on it, and I go to add equipment, the performance is pretty bad. It takes 4-5 seconds to get the list of data back from the server, scrolling the list is painful, and the cursor takes several seconds to settle on an item. Repainting the page after the list goes away is slow. This is occurring in IE7, latest version. FF3 and Chrome are fine, very snappy. The pagesize is about 40K overall. I'm thinking this is an issue with the IE7 Javascript engine, or an edge case with this plugin and IE7; it works quickly enough in FF3+. I would appreciate any ideas, solutions, known issues, or thoughts on how to more specifically pin this down. I'd love to post sample code, but this is a corporate app, and I'm not how useful it would be given that the server side piece cannot be shown; ie: you can't pull it down and test it like a self contained piece of code.. Thanks in advance! Chris

    Read the article

  • Which is a good way to maintain resources for Internationalization in .Net

    - by ashtee
    I have thought of three approaches to create and maintain resources in .Net projects for WinForms using Visual Studio 2008. (I am sure there should be more than three ways.) I need to decide on one before starting to implement internationalization for our product. Have individual sets of resource files (resx) for each windows form or piece of UI (a custom control) in each .net project. These are auto generated by Visual Studio when Localizable property is set to true in the form or control properties. Have one resource file per .net project. This is added manually and updated manually with the resource strings and messages. Have one resource manager project that has resources for all the components for a set of .net projects. Personally, I do not like the first approach as it creates numerous resources files. The only advantage we get in this approach is that we do not need to set text in UI elements manually. I like second and third approach as they are easy to maintain and there is only one set of resources that you need to handle. So no duplication of strings and messages. Easy for the translators also. What are your thoughts? Please share.

    Read the article

  • Java Performance measurement

    - by portoalet
    Hi, I am doing some Java performance comparison between my classes, and wondering if there is some sort of Java Performance Framework to make writing performance measurement code easier? I.e, what I am doing now is trying to measure what effect does it have having a method as "synchronized" as in PseudoRandomUsingSynch.nextInt() compared to using an AtomicInteger as my "synchronizer". So I am trying to measure how long it takes to generate random integers using 3 threads accessing a synchronized method looping for say 10000 times. I am sure there is a much better way doing this. Can you please enlighten me? :) public static void main( String [] args ) throws InterruptedException, ExecutionException { PseudoRandomUsingSynch rand1 = new PseudoRandomUsingSynch((int)System.currentTimeMillis()); int n = 3; ExecutorService execService = Executors.newFixedThreadPool(n); long timeBefore = System.currentTimeMillis(); for(int idx=0; idx<100000; ++idx) { Future<Integer> future = execService.submit(rand1); Future<Integer> future1 = execService.submit(rand1); Future<Integer> future2 = execService.submit(rand1); int random1 = future.get(); int random2 = future1.get(); int random3 = future2.get(); } long timeAfter = System.currentTimeMillis(); long elapsed = timeAfter - timeBefore; out.println("elapsed:" + elapsed); } the class public class PseudoRandomUsingSynch implements Callable<Integer> { private int seed; public PseudoRandomUsingSynch(int s) { seed = s; } public synchronized int nextInt(int n) { byte [] s = DonsUtil.intToByteArray(seed); SecureRandom secureRandom = new SecureRandom(s); return ( secureRandom.nextInt() % n ); } @Override public Integer call() throws Exception { return nextInt((int)System.currentTimeMillis()); } } Regards

    Read the article

  • Adding a font for use in ReportLab

    - by Jimmy McCarthy
    I'm trying to add a font to the python ReportLab so that I can use it for a function. The function is using canvas.Canvas to draw a bunch of text in a PDF, nothing complicated, but I need to add a fixed width font for layout issues. When I tried to register a font using what little info I could find, that seemed to work. But when I tried to call .addFont('fontname') from my Canvas object I keep getting "PDFDocument instance has no attribute 'addFont'" Is the function just not implemented? How do I get access to fonts other than the 10 or so default ones that are listed in .getAvailableFonts? Thanks. Some example code of what I'm trying to make happen: from reportlab.pdfgen import canvas c = canvas.Canvas('label.pdf') c.addFont('TestFont') #This throws the error listed above, regardless of what argument I use (whether it refers to a font or not). c.drawString(1,1,'test data here') c.showPage() c.save() To register the font, I tried from reportlab.lib.fonts import addMapping from reportlab.pdfbase import pdfmetrics pdfmetrics.registerFont(TTFont('TestFont', 'ghettomarquee.ttf')) addMapping('TestFont', 0, 0, 'TestFont') where 'ghettomarquee.ttf' was just a random font I had lying around.

    Read the article

  • Unittesting aspect-oriented features.

    - by Tomas Brambora
    Hi, I'd like to know what would you propose as the best way to unit test aspect-oriented application features (well, perhaps that's not the best name, but it's the best I was able to come up with :-) ) such as logging or security? These things are sort of omni-present in the application, so how to test them properly? E.g. say that I'm writing a Cherrypy web server in Python. I can use a decorator to check whether the logged-in user has the permission to access a given page. But then I'd need to write a test for every page to see whether it works oK (or more like to see that I had not forgotten to check security perms for that page). This could maybe (emphasis on maybe) be bearable if logging and/or security were implemented during the web server "normal business implementation". However, security and logging usually tend to be added to the app as an afterthough (or maybe that's just my experience, I'm usually given a server and then asked to implement security model :-) ). Any thoughts on this are very welcome. I have currently 'solved' this issue by, well - not testing this at all. Thanks.

    Read the article

  • Retactoring advanced has_many example

    - by atmorell
    Hello, My user model has three relations for the same message model, and is using raw SQL :/ Is there a better more rails way to achieve the same result? Could the foreign key be changed dynamically? e.g User.messages.sent (foreign key = author_id) and User.messages.received (foreign key = recipient ) I have been trying to move some of the logic into scopes in the message model, but the user.id is not available from the message model... Any thoughts? Table layout: create_table "messages", :force => true do |t| t.string "subject" t.text "body" t.datetime "created_at" t.datetime "updated_at" t.integer "author_id" t.integer "recipient_id" t.boolean "author_deleted", :default => false t.boolean "recipient_deleted", :default => false end This is my relations for my user model: has_many :messages_received, :foreign_key => "recipient_id", :class_name => "Message", :conditions => ['recipient_deleted = ?', false] has_many :messages_sent, :foreign_key => "author_id", :class_name => "Message", :conditions => ['author_deleted = ?', false] has_many :messages_deleted, :class_name => "Message", :finder_sql => 'SELECT * FROM Messages WHERE author_id = #{self.id} AND author_deleted = true OR recipient_id = #{self.id} AND recipient_deleted = true' Best regards. Asbjørn Morell

    Read the article

  • Is it valid to use unsafe struct * as an opaque type instead of IntPtr in .NET Platform Invoke?

    - by David Jeske
    .NET Platform Invoke advocates declaring pointer types as IntPtr. For example, the following [DllImport("user32.dll")] static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, Int32 wParam, Int32 lParam); However, I find when interfacing with interesting native interfaces, that have many pointer types, flattening everything into IntPtr makes the code very hard to read and removes the typical typechecking that a compiler can do. I've been using a pattern where I declare an unsafe struct to be an opaque pointer type. I can store this pointer type in a managed object, and the compiler can typecheck it form me. For example: class Foo { unsafe struct FOO {}; // opaque type unsafe FOO *my_foo; class if { [DllImport("mydll")] extern static unsafe FOO* get_foo(); [DllImport("mydll")] extern static unsafe void do_something_foo(FOO *foo); } public unsafe Foo() { this.my_foo = if.get_foo(); } public unsafe do_something_foo() { if.do_something_foo(this.my_foo); } While this example may not seem different than using IntPtr, when there are several pointer types moving between managed and native code, using these opaque pointer types for typechecking is a godsend. I have not run into any trouble using this technique in practice. However, I also have not seen an examples of anyone using this technique, and I wonder why. Is there any reason that the above code is invalid in the eyes of the .NET runtime? My main question is about how the .NET GC system treats "unsafe FOO *my_foo". Is this pointer something the GC system is going to try to trace, or is it simply going to ignore it? My hope is that because the underlying type is a struct, and it's declared unsafe, that the GC would ignore it. However, I don't know for sure. Thoughts?

    Read the article

  • Number Algorithm

    - by James
    I've been struggling to wrap my head around this for some reason. I have 15 bits that represent a number. The bits must match a pattern. The pattern is defined in the way the bits start out: they are in the most flush-right representation of that pattern. So say the pattern is 1 4 1. The bits will be: 000000010111101 So the general rule is, take each number in the pattern, create that many bits (1, 4 or 1 in this case) and then have at least one space separating them. So if it's 1 2 6 1 (it will be random): 001011011111101 Starting with the flush-right version, I want to generate every single possible number that meets that pattern. The # of bits will be stored in a variable. So for a simple case, assume it's 5 bits and the initial bit pattern is: 00101. I want to generate: 00101 01001 01010 10001 10010 10100 I'm trying to do this in Objective-C, but anything resembling C would be fine. I just can't seem to come up with a good recursive algorithm for this. It makes sense in the above example, but when I start getting into 12431 and having to keep track of everything it breaks down.

    Read the article

  • Finding a picture in a picture with java?

    - by tarrasch
    what i want to to is analyse input from screen in form of pictures. I want to be able to identify a part of an image in a bigger image and get its coordinates within the bigger picture. Example: would have to be located in And the result would be the upper right corner of the picture in the big picture and the lower left of the part in the big picture. As you can see, the white part of the picture is irrelevant, what i basically need is just the green frame. Is there a library that can do something like this for me? Runtime is not really an issue. What i want to do with this is just generating a few random pixel coordinates and recognize the color in the big picture at that position, to recognize the green box fast later. And how would it decrease performance, if the white box in the middle is transparent? The question has been asked several times on SO as it seems without a single answer. I found i found a solution at http://werner.yellowcouch.org/Papers/subimg/index.html . Unfortunately its in C++ and i do not understand a thing. Would be nice to have a Java implementation on SO.

    Read the article

  • How do you localize/internationalize an MVC Controller when using a SQL based localization provider?

    - by EBarr
    Hopefully this isn't too silly of a question. In MVC there appears to be plenty of localization support in the views. Once I get to the controller, however, it becomes murky. Using meta:resourcekey="blah" is out, same with <%$ Resources:PageTitle.Text%. ASP.NET MVC - Localization Helpers -- suggested extensions for the Html helper classes like Resource(this Controller controller, string expression, params object[] args). Similarly, Localize your MVC with ease suggested a slightly different extension like Localize(this System.Web.UI.UserControl control, string resourceKey, params object[] args) None of these approaches works while in a controller. I put together the below function and I'm using the controllers full class name as my VirtualPath. But I'm new to MVC and assume there's a better way. public static string Localize (System.Type theType, string resourceKey, params object[] args) { string resource = (HttpContext.GetLocalResourceObject(theType.FullName, resourceKey) ?? string.Empty).ToString(); return mergeTokens(resource, args); } Thoughts? Comments?

    Read the article

  • Binary search in a sorted (memory-mapped ?) file in Java

    - by sds
    I am struggling to port a Perl program to Java, and learning Java as I go. A central component of the original program is a Perl module that does string prefix lookups in a +500 GB sorted text file using binary search (essentially, "seek" to a byte offset in the middle of the file, backtrack to nearest newline, compare line prefix with the search string, "seek" to half/double that byte offset, repeat until found...) I have experimented with several database solutions but found that nothing beats this in sheer lookup speed with data sets of this size. Do you know of any existing Java library that implements such functionality? Failing that, could you point me to some idiomatic example code that does random access reads in text files? Alternatively, I am not familiar with the new (?) Java I/O libraries but would it be an option to memory-map the 500 GB text file (I'm on a 64-bit machine with memory to spare) and do binary search on the memory-mapped byte array? I would be very interested to hear any experiences you have to share about this and similar problems.

    Read the article

< Previous Page | 293 294 295 296 297 298 299 300 301 302 303 304  | Next Page >