Search Results

Search found 7517 results on 301 pages for 'fast debugger'.

Page 278/301 | < Previous Page | 274 275 276 277 278 279 280 281 282 283 284 285  | Next Page >

• Persistent (purely functional) Red-Black trees on disk performance

  - by Waneck

  I'm studying the best data structures to implement a simple open-source object temporal database, and currently I'm very fond of using Persistent Red-Black trees to do it. My main reasons for using persistent data structures is first of all to minimize the use of locks, so the database can be as parallel as possible. Also it will be easier to implement ACID transactions and even being able to abstract the database to work in parallel on a cluster of some kind. The great thing of this approach is that it makes possible implementing temporal databases almost for free. And this is something quite nice to have, specially for web and for data analysis (e.g. trends). All of this is very cool, but I'm a little suspicious about the overall performance of using a persistent data structure on disk. Even though there are some very fast disks available today, and all writes can be done asynchronously, so a response is always immediate, I don't want to build all application under a false premise, only to realize it isn't really a good way to do it. Here's my line of thought: - Since all writes are done asynchronously, and using a persistent data structure will enable not to invalidate the previous - and currently valid - structure, the write time isn't really a bottleneck. - There are some literature on structures like this that are exactly for disk usage. But it seems to me that these techniques will add more read overhead to achieve faster writes. But I think that exactly the opposite is preferable. Also many of these techniques really do end up with a multi-versioned trees, but they aren't strictly immutable, which is something very crucial to justify the persistent overhead. - I know there still will have to be some kind of locking when appending values to the database, and I also know there should be a good garbage collecting logic if not all versions are to be maintained (otherwise the file size will surely rise dramatically). Also a delta compression system could be thought about. - Of all search trees structures, I really think Red-Blacks are the most close to what I need, since they offer the least number of rotations. But there are some possible pitfalls along the way: - Asynchronous writes -could- affect applications that need the data in real time. But I don't think that is the case with web applications, most of the time. Also when real-time data is needed, another solutions could be devised, like a check-in/check-out system of specific data that will need to be worked on a more real-time manner. - Also they could lead to some commit conflicts, though I fail to think of a good example of when it could happen. Also commit conflicts can occur in normal RDBMS, if two threads are working with the same data, right? - The overhead of having an immutable interface like this will grow exponentially and everything is doomed to fail soon, so this all is a bad idea. Any thoughts? Thanks! edit: There seems to be a misunderstanding of what a persistent data structure is: http://en.wikipedia.org/wiki/Persistent_data_structure

  Read the article

• What is your most productive shortcut with Vim?

  - by Olivier Pons

  I've heard a lot about Vim, both pros and cons. It really seems you should be (as a developer) faster with Vim than with any other editor. I'm using Vim to do some basic stuff and I'm at best 10 times less productive with Vim. The only two things you should care about when you talk about speed (you may not care enough about them, but you should) are: Using alternatively left and right hands is the fastest way to use the keyboard. Never touching the mouse is the second way to be as fast as possible. It takes ages for you to move your hand, grab the mouse, move it, and bring it back to the keyboard (and you often have to look at the keyboard to be sure you returned your hand properly to the right place) Here are two examples demonstrating why I'm far less productive with Vim. Copy/Cut & paste. I do it all the time. With all the classical editors you press Shift with the left hand, and you move the cursor with your right hand to select text. Then Ctrl+C copies, you move the cursor and Ctrl+V pastes. With Vim it's horrible: yy to copy one line (you almost never want the whole line!) [number xx]yy to copy xx lines into the buffer. But you never know exactly if you've selected what you wanted. I often have to do [number xx]dd then u to undo! Another example? Search & replace. In PSPad: Ctrl+f then type what you want you search for, then press Enter. In Vim: /, then type what you want to search for, then if there are some special characters put \ before each special character, then press Enter. And everything with Vim is like that: it seems I don't know how to handle it the right way. NB : I've already read the Vim cheat sheet :) My question is: What is the way you use Vim that makes you more productive than with a classical editor?

  Read the article

• Combinations and Permutations in F#

  - by Noldorin

  I've recently written the following combinations and permutations functions for an F# project, but I'm quite aware they're far from optimised. /// Rotates a list by one place forward. let rotate lst = List.tail lst @ [List.head lst] /// Gets all rotations of a list. let getRotations lst = let rec getAll lst i = if i = 0 then [] else lst :: (getAll (rotate lst) (i - 1)) getAll lst (List.length lst) /// Gets all permutations (without repetition) of specified length from a list. let rec getPerms n lst = match n, lst with | 0, _ -> seq [[]] | _, [] -> seq [] | k, _ -> lst |> getRotations |> Seq.collect (fun r -> Seq.map ((@) [List.head r]) (getPerms (k - 1) (List.tail r))) /// Gets all permutations (with repetition) of specified length from a list. let rec getPermsWithRep n lst = match n, lst with | 0, _ -> seq [[]] | _, [] -> seq [] | k, _ -> lst |> Seq.collect (fun x -> Seq.map ((@) [x]) (getPermsWithRep (k - 1) lst)) // equivalent: | k, _ -> lst |> getRotations |> Seq.collect (fun r -> List.map ((@) [List.head r]) (getPermsWithRep (k - 1) r)) /// Gets all combinations (without repetition) of specified length from a list. let rec getCombs n lst = match n, lst with | 0, _ -> seq [[]] | _, [] -> seq [] | k, (x :: xs) -> Seq.append (Seq.map ((@) [x]) (getCombs (k - 1) xs)) (getCombs k xs) /// Gets all combinations (with repetition) of specified length from a list. let rec getCombsWithRep n lst = match n, lst with | 0, _ -> seq [[]] | _, [] -> seq [] | k, (x :: xs) -> Seq.append (Seq.map ((@) [x]) (getCombsWithRep (k - 1) lst)) (getCombsWithRep k xs) Does anyone have any suggestions for how these functions (algorithms) can be sped up? I'm particularly interested in how the permutation (with and without repetition) ones can be improved. The business involving rotations of lists doesn't look too efficient to me in retrospect. Update Here's my new implementation for the getPerms function, inspired by Tomas's answer. Unfortunately, it's not really any fast than the existing one. Suggestions? let getPerms n lst = let rec getPermsImpl acc n lst = seq { match n, lst with | k, x :: xs -> if k > 0 then for r in getRotations lst do yield! getPermsImpl (List.head r :: acc) (k - 1) (List.tail r) if k >= 0 then yield! getPermsImpl acc k [] | 0, [] -> yield acc | _, [] -> () } getPermsImpl List.empty n lst

  Read the article

• Choosing the right .NET architecture. WCF? WPF/Forms, ASP.NET (MVC)?

  - by Tommy Jakobsen

  I’m in the situation that I have to design and implement a rather big system from the bottom. I’m having some (a lot actually) questions about the architecture that I would like your comments and thoughts on. I don’t hope that I’ve written too much here, but I wanted to give you all an idea of what the system is. Quick info about the applications, read if you want: I can’t share much detail about the project, but basically it’s a system where we offer our customer a service to manage their users. We have a hotline where the users call and our hotline uses an (windows) application (intranet) to manage the user’s data, etc. The customer also has a web application where they can see reports, information about their business and users, and the ability to modify their data. Modifying data is not just user data like address and so, but also information about the products/services the user has, which can be complicated. The applications will be built on Microsoft .NET Framework 4, with a MS SQL Server 2008 database. There will be a few applications that have to access this database, such as: Intranet application (used by us and our hotline) Customer web application type 1 Customer web application type 2 Customer web application type n different applications) … Now my big problem is what .NET parts I should use for such a system. For the “backend” I’ve considered using Windows Communication Foundation: Would WCF be a good choice? The intranet application will be an application that has to edit lots of records in the database. It has to be easy to navigate using the keyboard (fast to work with). Has a feature such as “find customer, find that, lookup this, choose this and update that”. What would be the best choice to develop this application in? Would it be WPF or good old Windows Forms? I don’t need all of the fancy graphics features in WPF, like 3D, but the application has to look nice (maybe something like the new Visual Studio/Office tools). And the same question goes for the web pages. They have much the same work to do, but not as many features as the intranet application, and not the same amount of data (much less). That is my questions for now. I’m hoping to get a discussion going that will open my eyes to some of these technologies, helping me decide architecture to go with. I would like to say thanks in advance, and let you all know that any thoughts will be much appreciated.

  Read the article

• Programming graphics and sound on PC - Total newbie questions, and lots of them!

  - by Russel

  Hello, This isn't exactly specifically a programming question (or is it?) but I was wondering: How are graphics and sound processed from code and output by the PC? My guess for graphics: There is some reserved memory space somewhere that holds exactly enough room for a frame of graphics output for your monitor. IE: 800 x 600, 24 bit color mode == 800x600x3 = ~1.4MB memory space Between each refresh, the program writes video data to this space. This action is completed before the monitor refresh. Assume a simple 2D game: the graphics data is stored in machine code as many bytes representing color values. Depending on what the program(s) being run instruct the PC, the processor reads the appropriate data and writes it to the memory space. When it is time for the monitor to refresh, it reads from each memory space byte-for-byte and activates hardware depending on those values for each color element of each pixel. All of this of course happens crazy-fast, and repeats x times a second, x being the monitor's refresh rate. I've simplified my own likely-incorrect explanation by avoiding talk of double buffering, etc Here are my questions: a) How close is the above guess (the three steps)? b) How could one incorporate graphics in pure C++ code? I assume the practical thing that everyone does is use a graphics library (SDL, OpenGL, etc), but, for example, how do these libraries accomplish what they do? Would manual inclusion of graphics in pure C++ code (say, a 2D spite) involve creating a two-dimensional array of bit values (or three dimensional to include multiple RGB values per pixel)? Is this how it would be done waaay back in the day? c) Also, continuing from above, do libraries such as SDL etc that use bitmaps actual just build the bitmap/etc files into machine code of the executable and use them as though they were build in the same matter mentioned in question b above? d) In my hypothetical step 3 above, is there any registers involved? Like, could you write some byte value to some register to output a single color of one byte on the screen? Or is it purely dedicated memory space (=RAM) + hardware interaction? e) Finally, how is all of this done for sound? (I have no idea :) )

  Read the article

• Core Plot causing crash on device but not simulator.

  - by Eric

  I'm using core plot to create a small plot in one of my view controllers. I have been pulling my hair out trying to track down this error. I install on the simulator and it works fine but as soon as I put it on my device I get the following error: 2010-02-04 22:15:37.394 Achieve[127:207] *** -[NSCFString drawAtPoint:withTextStyle:inContext:]: unrecognized selector sent to instance 0x108530 2010-02-04 22:15:37.411 Achieve[127:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFString drawAtPoint:withTextStyle:inContext:]: unrecognized selector sent to instance 0x108530' 2010-02-04 22:15:37.427 Achieve[127:207] Stack: ( 843263261, 825818644, 843267069, 842763033, 842725440, 253481, 208187, 823956912, 823956516, 823956336, 823953488, 823952500, 823985628, 842717233, 843010887, 843009055, 860901832, 843738160, 843731504, 8797, 8692 ) terminate called after throwing an instance of 'NSException' Program received signal: “SIGABRT”. Debugger Output (as requested): #0 0x33b3db2c in __kill #1 0x33b3db20 in kill #2 0x33b3db14 in raise #3 0x33b54e3a in abort #4 0x33c5c398 in __gnu_cxx::__verbose_terminate_handler #5 0x313918a0 in _objc_terminate #6 0x33c59a8c in __cxxabiv1::__terminate #7 0x33c59b04 in std::terminate #8 0x33c59c2c in __cxa_throw #9 0x3138fe5c in objc_exception_throw #10 0x32433bfc in -[NSObject doesNotRecognizeSelector:] #11 0x323b8b18 in ___forwarding___ #12 0x323af840 in __forwarding_prep_0___ #13 0x0003de28 in -[CPTextLayer renderAsVectorInContext:] at CPTextLayer.m:117 #14 0x00032d3a in -[CPLayer drawInContext:] at CPLayer.m:146 #15 0x311c95b0 in -[CALayer _display] #16 0x311c9424 in -[CALayer display] #17 0x311c9370 in CALayerDisplayIfNeeded #18 0x311c8850 in CA::Context::commit_transaction #19 0x311c8474 in CA::Transaction::commit #20 0x311d05dc in CA::Transaction::observer_callback #21 0x323ad830 in __CFRunLoopDoObservers #22 0x323f5346 in CFRunLoopRunSpecific #23 0x323f4c1e in CFRunLoopRunInMode #24 0x335051c8 in GSEventRunModal #25 0x324a6c30 in -[UIApplication _run] #26 0x324a5230 in UIApplicationMain #27 0x0000225c in main at main.m:14 Here is my viewDidLoad method: - (void)viewDidLoad { [super viewDidLoad]; self.view.backgroundColor = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"bg.png"]]; [self loadData]; self.graph = [[CPXYGraph alloc] initWithFrame: self.plotView.frame]; CPLayerHostingView *hostingView = self.plotView; hostingView.hostedLayer = graph; graph.paddingLeft = 50; graph.paddingTop = 10; graph.paddingRight = 10; graph.paddingBottom = 10; percentFormatter = [[NSNumberFormatter alloc] init]; [percentFormatter setPercentSymbol:@"%"]; [percentFormatter setNumberStyle:NSNumberFormatterPercentStyle]; [percentFormatter setLocale: [NSLocale currentLocale]]; [percentFormatter setMultiplier:[NSNumber numberWithInt:1]]; [percentFormatter setMaximumFractionDigits:0]; CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace; plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0) length:CPDecimalFromFloat(maxX)]; plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(minY) length:CPDecimalFromFloat(maxY-minY)]; CPLineStyle *lineStyle = [[CPLineStyle lineStyle]retain]; lineStyle.lineColor = [CPColor grayColor]; lineStyle.lineWidth = 1.0f; CPTextStyle *whiteText = [CPTextStyle textStyle]; whiteText.color = [CPColor whiteColor]; CPXYAxisSet *axisSet = (CPXYAxisSet *)graph.axisSet; // axisSet.xAxis.majorIntervalLength = [[NSDecimalNumber decimalNumberWithString:@"0"]decimalValue]; axisSet.xAxis.minorTicksPerInterval = 0; axisSet.xAxis.majorTickLineStyle = nil; axisSet.xAxis.minorTickLineStyle = nil; axisSet.xAxis.axisLineStyle = lineStyle; axisSet.xAxis.minorTickLength = 0; axisSet.xAxis.majorTickLength = 0; axisSet.xAxis.labelFormatter = nil; axisSet.xAxis.labelTextStyle = nil; axisSet.yAxis.majorIntervalLength = [[NSDecimalNumber decimalNumberWithString:intY]decimalValue]; axisSet.yAxis.minorTicksPerInterval = 5; axisSet.yAxis.majorTickLineStyle = lineStyle; axisSet.yAxis.minorTickLineStyle = lineStyle; axisSet.yAxis.axisLineStyle = lineStyle; axisSet.yAxis.minorTickLength = 2.0f; axisSet.yAxis.majorTickLength = 4.0f; axisSet.yAxis.labelFormatter = percentFormatter; axisSet.yAxis.labelTextStyle = whiteText; CPScatterPlot *xSquaredPlot = [[[CPScatterPlot alloc]initWithFrame:graph.defaultPlotSpace.graph.bounds] autorelease]; xSquaredPlot.identifier = @"Plot"; xSquaredPlot.dataLineStyle.lineWidth = 4.0f; xSquaredPlot.dataLineStyle.lineColor = [CPColor yellowColor]; xSquaredPlot.dataSource = self; [graph addPlot:xSquaredPlot]; } Any help would be appreciated!

  Read the article

• JQuery fadeIn after src changed but fadeIn on the previous src anyway !

  - by Anna

  Hello ! I have a jquery bug and I've been looking for hours now, I can't figure out what's wrong... I have this code : $(document).ready(function(){ $('#ulPhotos a').click(function() { var newSrc= $(this).find('img').attr('src').split("/"); bigPictureName = 'big'+newSrc[2]; $('#pho').hide(); $('#imageBig').attr("src", "images/photos/"+bigPictureName); $('#pho').fadeIn('slow'); var alt = $(this).find('img').attr('alt'); $('#legend').html(alt); }); }); and this in html : <ul id="ulPhotos"> <li><a href="#centre"><img src="images/photos/09.jpg" title="La Reine de la Nuit au Comedia" alt="<em>La Reine de la Nuit</em> au Comedia"/></a> <a href="#centre"><img src="images/photos/03.jpg" title="Manuelita, La Périchole à l&rsquo;Opéra Comique" alt="Manuelita, <em>La Périchole</em> à l&#8217;Opéra Comique" /></a></li> <li><a href="#centre" ><img src="images/photos/12.png" title="" alt="Marion Baglan Carnac Ré" /></a> and this in for bigImage : </div> <div id="pho" a name="centre"> <p id="legend"> La Reine de la Nuit</p> <img src="images/photos/big09.jpg" alt="Marion Baglan" id="imageBig"/> </div> It simply changes the source of my img in a div named pho... but sometimes when the new image is too heavy, the fadeIn executes on the previous src !! so we see the fadeIn first on the previous image, and then, the right picture appears without fadeIn.... am I missing something? ps : the page is here http://www.marion-baglan.net/photos.htm#centre if you click fast you can see it... and when I try to put some bigger photos, it's very obvious...

  Read the article

• Should we denormalize database to improve performance?

  - by Groo

  We have a requirement to store 500 measurements per second, coming from several devices. Each measurement consists of a timestamp, a quantity type, and several vector values. Right now there is 8 vector values per measurement, and we may consider this number to be constant for needs of our prototype project. We are using HNibernate. Tests are done in SQLite (disk file db, not in-memory), but production will probably be MsSQL. Our Measurement entity class is the one that holds a single measurement, and looks like this: public class Measurement { public virtual Guid Id { get; private set; } public virtual Device Device { get; private set; } public virtual Timestamp Timestamp { get; private set; } public virtual IList<VectorValue> Vectors { get; private set; } } Vector values are stored in a separate table, so that each of them references its parent measurement through a foreign key. We have done a couple of things to ensure that generated SQL is (reasonably) efficient: we are using Guid.Comb for generating IDs, we are flushing around 500 items in a single transaction, ADO.Net batch size is set to 100 (I think SQLIte does not support batch updates? But it might be useful later). The problem Right now we can insert 150-200 measurements per second (which is not fast enough, although this is SQLite we are talking about). Looking at the generated SQL, we can see that in a single transaction we insert (as expected): 1 timestamp 1 measurement 8 vector values which means that we are actually doing 10x more single table inserts: 1500-2000 per second. If we placed everything (all 8 vector values and the timestamp) into the measurement table (adding 9 dedicated columns), it seems that we could increase our insert speed up to 10 times. Switching to SQL server will improve performance, but we would like to know if there might be a way to avoid unnecessary performance costs related to the way database is organized right now. [Edit] With in-memory SQLite I get around 350 items/sec (3500 single table inserts), which I believe is about as good as it gets with NHibernate (taking this post for reference: http://ayende.com/Blog/archive/2009/08/22/nhibernate-perf-tricks.aspx). But I might as well switch to SQL server and stop assuming things, right? I will update my post as soon as I test it.

  Read the article

• Getting <divs>'s to align next to each other

  - by user1322845

  I have the following code I am trying to get working correctly: <div id="newspost_bg"> <article> <p> <header><h3>The fast red fox!</h3></header> This is where the article resides in the article tag. This is good for SEO optimization. <footer>Read More..</footer> </p> </article> </div> <div id="newspost_bg"> hello </div> <div id="newspost_bg"> hello </div> <div id="advertisement"> <script type="text/javascript"><!-- google_ad_client = "ca-pub-2139701283631933"; /* testing site */ google_ad_slot = "4831288817"; google_ad_width = 120; google_ad_height = 600; //--> </script> </div> Here is the css that goes with it: #newspost_bg{ position: relative; background-color: #d9dde1; width:700px; height:250px; margin: 10px; margin-left: 20px; border: solid 10px #1d2631; float:left; } #newspost_bg article{ position: relative; margin-left: 20px; } #advertisement{ float: left; background-color: #d9dde1; width: 125px; height: 605px; margin: 10px; } The problem I'm experiencing is that the advertisements im trying to get setup will align with the last with the id of newspost_bg but im looking to havce it align to the top of the container it is in. I dont know if this is enough info, if not please let me know what you might need. Im new to the web coding scene so any and all critiques help me.

  Read the article

• log4j performance

  - by Bob

  Hi, I'm developing a web app, and I'd like to log some information to help me improve and observe the app. (I'm using Tomcat6) First I thought I would use StringBuilders, append the logs to them and a task would persist them into the database like every 2 minutes. Because I was worried about the out-of-the-box logging system's performance. Then I made some test. Especially with log4j. Here is my code: Main.java public static void main(String[] args) { Thread[] threads = new Thread[LoggerThread.threadsNumber]; for(int i = 0; i < LoggerThread.threadsNumber; ++i){ threads[i] = new Thread(new LoggerThread("name - " + i)); } LoggerThread.startTimestamp = System.currentTimeMillis(); for(int i = 0; i < LoggerThread.threadsNumber; ++i){ threads[i].start(); } LoggerThread.java public class LoggerThread implements Runnable{ public static int threadsNumber = 10; public static long startTimestamp; private static int counter = 0; private String name; public LoggerThread(String name) { this.name = name; } private Logger log = Logger.getLogger(this.getClass()); @Override public void run() { for(int i=0; i<10000; ++i){ log.info(name + ": " + i); if(i == 9999){ int c = increaseCounter(); if(c == threadsNumber){ System.out.println("Elapsed time: " + (System.currentTimeMillis() - startTimestamp)); } } } } private synchronized int increaseCounter(){ return ++counter; } } } log4j.properties log4j.logger.main.LoggerThread=debug, f log4j.appender.f=org.apache.log4j.RollingFileAppender log4j.appender.f.layout=org.apache.log4j.PatternLayout log4j.appender.f.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n log4j.appender.f.File=c:/logs/logging.log log4j.appender.f.MaxFileSize=15000KB log4j.appender.f.MaxBackupIndex=50 I think this is a very common configuration for log4j. First I used log4j 1.2.14 then I realized there was a newer version, so I switched to 1.2.16 Here are the figures (all in millisec) LoggerThread.threadsNumber = 10 1.2.14: 4235, 4267, 4328, 4282 1.2.16: 2780, 2781, 2797, 2781 LoggerThread.threadsNumber = 100 1.2.14: 41312, 41014, 42251 1.2.16: 25606, 25729, 25922 I think this is very fast. Don't forget that: in every cycle the run method not just log into the file, it has to concatenate strings (name + ": " + i), and check an if test (i == 9999). When threadsNumber is 10, there are 100.000 loggings and if tests and concatenations. When it is 100, there are 1.000.000 loggings and if tests and concatenations. (I've read somewhere JVM uses StringBuilder's append for concatenation, not simple concatenation). Did I missed something? Am I doing something wrong? Did I forget any factor that could decrease the performance? If these figures are correct I think, I don't have to worry about log4j's performance even if I heavily log, do I?

  Read the article

• Clickin issue in Flash and XML

  - by ortho

  Hi, I have the php backend that displays an xml page with data for flash consuming. Flash takes it and creates a textfields dynamicaly based on this information. I have a few items in menu on top and when I click one of them, data is taken from php and everything is displayed in scroll in flash. The problem is that if I click too fast between menu items, then I get buggy layout. The text (only the text) is becoming part of the layout and is displayed no metter what item in menu I am currently in and only refreshing the page helps. var myXML:XML = new XML(); myXML.ignoreWhite=true; myXML.load("/getBud1.php"); myXML.onLoad = function(success){ if (success){ var myNode = this.firstChild.childNodes; var myTxt:Array = Array(0); for (var i:Number = 0; i<myNode.length; i++) { myTxt[i] = "text"+i+"content"; createTextField(myTxt[i],i+1,65,3.5,150, 20); var pole = eval(myTxt[i]); pole.embedFonts = true; var styl:TextFormat = new TextFormat(); styl.font = "ArialFont"; pole.setNewTextFormat(styl); pole.text = String(myNode[i].childNodes[1].firstChild.nodeValue); pole.wordWrap = true; pole.autoSize = "left"; if(i > 0) { var a:Number = eval(myTxt[i-1])._height + eval(myTxt[i-1])._y + 3; pole._y = a; } attachMovie("kropka2", "test"+i+"th", i+1000); eval("test"+i+"th")._y = pole._y + 5; eval("test"+i+"th")._x = 52; } } } I tried to load the info and ceate text fields from top frame and then refer to correct place by instance names string e.g. budData.dataHolder.holder.createTextField , but then when I change between items in menu the text dissapears completely untill I refresh the page. Please help

  Read the article

• show/hide html table columns using css

  - by Art Peterson

  I want to display a basic html table with controls to toggle showing/hiding of additional columns: <table id="mytable"> <tr> <th>Column 1</th> <th class="col1">1a</th> <th class="col1">1b</th> <th>Column 2</th> <th class="col2">2a</th> <th class="col2">2b</th> </tr> <tr> <td>100</td> <td class="col1">40</td> <td class="col1">60</td> <td>200</td> <td class="col2">110</td> <td class="col2">90</td> </tr> </table> So Column 1 and Column 2 will be the only columns displayed by default - but when you click on the Column 1 I want 1a and 1b to toggle, and same with Column 2 with 2a and 2b. I may end up with more columns and lots of rows - so any javascript looping approaches have been too slow to work with when I tested. The only approach that seems to be fast enough is to set up some css like this: table.hide1 .col1 { display: none; } table.hide2 .col2 { display: none; } table.hide3 .col3 { display: none; } table.show1 .col1 { display: table-cell; } table.show2 .col2 { display: table-cell; } table.show3 .col3 { display: table-cell; } And then set up onClick function calls on the table header cells that will trigger a toggle - and determine which css class to set "mytable" to that will create the toggle effect that I'm looking for. Is there an easy way to set this up so that the code can work for n # of columns?

  Read the article

• DCVS + hosting for a startup commercial multiplatform phone app

  - by AG

  I'm in lean startup mode, working on a simple phone app that will be published initially as a iThingy app and an Android app with, possibly, Blackberry and Symbian versions to follow. I'm about to go from no repository to needing a central repository that up to 4 very part-time resources will be sharing. Two of us have no version control background, one has used Subversion, and I've used most of the major centralized VCS systems. I'm not going to be pushing the technical limitations of any VCS for a long time; I'm sure that any of the major systems would work fine. And the hosting accounts I've looked at seem reasonable. So I'm really focussed on minimizing the downside risks. That is, I'd like to find a stable setup that is easy to learn in general, easy to use from Windows/Eclipse, and won't paint me into any obvious corners for the next 12 months or so. A quick search of the web had led me to consider the following pairs of DVCS and hosting service, with what I think I'm hearing as their strengths and weaknesses (for my purposes): Bazaar/Launchpad -- My initial choice since I need to get more familiar with this pair for the Google Summer of Code mentoring I'm doing. But, whatever the technical merits, a non-starter for me because they are purely open source, no private repositories plans to purchase that I can see. Git/GitHub -- Git: Fast, light, ultimately flexible, but relatively less Windows friendly, Eclipse plugin (eGit) available but relatively young, GitHub: widely used, pricing is fine Mercurial/BitBucket -- Mercurial: a little less flexible, a little more Windows friendly, Eclipse plugin seems a bit more mature, BitBucket: widely used, pricing is fine, includes a wiki and an issue tracker that we might be able to use instead of something like BaseCamp, at least for a while. Mercurial/BitBucket seem like the winning pair so far for my particular situation; at least two of us are definitely going to be working mostly from Eclipse on Windows and reducing my own learning curve is a priority. ;-) But I have two specific questions: 1) Am I wrong about Bazaar/Launchpad and is there a viable, secure way to use them for proprietary code? 2) Any reason to think that the Mecurial/Bitbucket pair will end up being a headache for my Mac developer, soon, or for Blackberry or Symbian developers a little later? ag

  Read the article

• Checking to see if a number is evenly divisible by other numbers with recursion in Python

  - by Ernesto

  At the risk of receiving negative votes, I will preface this by saying this is a midterm problem for a programming class. However, I have already submitted the code and passed the question. I changed the name of the function(s) so that someone can't immediately do a search and find the correct code, as that is not my purpose. I am actually trying to figure out what is actually MORE CORRECT from two pieces that I wrote. The problem tells us that a certain fast food place sells bite-sized pieces of chicken in packs of 6, 9, and 20. It wants us to create a function that will tell if a given number of bite-sized piece of chicken can be obtained by buying different packs. For example, 15 can be bought, because 6 + 9 is 15, but 16 cannot be bought, because no combination of the packs will equal 15. The code I submitted and was "correct" on, was: def isDivisible(n): """ n is an int Returns True if some integer combination of 6, 9 and 20 equals n Otherwise returns False. """ a, b, c = 20, 9, 6 if n == 0: return True elif n < 0: return False elif isDivisible(n - a) or isDivisible(n - b) or isDivisible(n - c): return True else: return False However, I got to thinking, if the initial number is 0, it will return True. Would an initial number of 0 be considered "buying that amount using 6, 9, and/or 20"? I cannot view the test cases the grader used, so I don't know if the grader checked 0 as a test case and decided that True was an acceptable answer or not. I also can't just enter the new code, because it is a midterm. I decided to create a second piece of code that would handle an initial case of 0, and assuming 0 is actually False: def isDivisible(n): """ n is an int Returns True if some integer combination of 6, 9 and 20 equals n Otherwise returns False. """ a, b, c = 20, 9, 6 if n == 0: return False else: def helperDivisible(n): if n == 0: return True elif n < 0: return False elif helperDivisible(n - a) or helperDivisible(n - b) or helperDivisible(n - c): return True else: return False return helperDivisible(n) As you can see, my second function had to use a "helper" function in order to work. My overall question, though, is which function do you think would provide the correct answer, if the grader had tested for 0 as an initial input?

  Read the article

• Retrieve names of running processes

  - by Dave DeLong

  Hi everyone, First off, I know that similar questions have been asked, but the answers provided haven't been very helpful so far (they all recommend one of the following options). I have a user application that needs to determine if a particular process is running. Here's what I know about the process: The name The user (root) It should already be running, since it's a LaunchDaemon, which means Its parent process should be launchd (pid 1) I've tried several ways to get this, but none have worked so far. Here's what I've tried: Running ps and parsing the output. This works, but it's slow (fork/exec is expensive), and I'd like this to be as fast as possible. Using the GetBSDProcessList function listed here. This also works, but the way in which they say to retrieve the process name (accessing kp_proc.p_comm from each kinfo_proc structure) is flawed. The resulting char* only contains the first 16 characters of the process name, which can be seen in the definition of the kp_proc structure: #define MAXCOMLEN 16 //defined in param.h struct extern_proc { //defined in proc.h ...snip... char p_comm[MAXCOMLEN+1]; ...snip... }; Using libProc.h to retrieve process information: pid_t pids[1024]; int numberOfProcesses = proc_listpids(PROC_ALL_PIDS, 0, NULL, 0); proc_listpids(PROC_ALL_PIDS, 0, pids, sizeof(pids)); for (int i = 0; i < numberOfProcesses; ++i) { if (pids[i] == 0) { continue; } char name[1024]; proc_name(pids[i], name, sizeof(name)); printf("Found process: %s\n", name); } This works, except it has the same flaw as GetBSDProcessList. Only the first portion of the process name is returned. Using the ProcessManager function in Carbon: ProcessSerialNumber psn; psn.lowLongOfPSN = kNoProcess; psn.highLongOfPSN = 0; while (GetNextProcess(&psn) == noErr) { CFStringRef procName = NULL; if (CopyProcessName(&psn, &procName) == noErr) { NSLog(@"Found process: %@", (NSString *)procName); } CFRelease(procName); } This does not work. It only returns process that are registered with the WindowServer (or something like that). In other words, it only returns apps with UIs, and only for the current user. I can't use -[NSWorkspace launchedApplications], since this must be 10.5-compatible. In addition, this only returns information about applications that appear in the Dock for the current user. I know that it's possible to retrieve the name of running processes (since ps can do it), but the question is "Can I do it without forking and exec'ing ps?". Any suggestions?

  Read the article

• Java Applet Deployment, ClassNotFoundException (primary class)

  - by Matt

  This is driving me up the wall. I have checked and rechecked spelling and paths. I have tried just about every combination of paths, including relative, absolute, and full http paths. I continue to get the following error when trying to load a Java applet: java.lang.ClassNotFoundException: AppletClient.class at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source) at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source) at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Exception: java.lang.ClassNotFoundException: AppletClient.class The HTML used to load the applet: <applet width="100" height="100" archive="applet/myapplet.jar, applet/applet_dependency.jar" code="AppletClient.class"> <param value="blahblah" name="username"> <param value="false" name="codebase_lookup"> </applet> The applet is in a relative directory, "applet", from the path of the current page. I have unzipped the jar file and can see AppletClient.class. Also, in the source of the project, it is spelled that way (casing and all). I have tried with/without the parameters. I have changed the names of the archive jars in the applet include tag just to see if I get a different error for bad file names (same error). I have manually done GETs on the jars to make sure the server is responding to the requests (it is). I have tried with and without the codebase tag, with all different varieties of paths (start getting bad "magic number" errors on those). I know that this error sometimes pops up when a dependency fails to load, so it can be misleading, but all dependencies are present, accounted for, and are fetchable via manual GETs. Between each and every attempt I always clear my cache in FireFox. These problems are reproduced in IE8 and Chrome as well. Per my Java Console from the browser, I am running Java Plug-in 1.6.0_20. This is from the same machine that I develop the applet on, which runs fine via Eclipse. Finally, I kicked on Fiddler2, and I don't see a single request for the jar files anywhere The host site is running from my Visual Studio debugger, so it's running on localhost. But I see the requests for all the other resources on Fiddler. Just... no Jars. ANYWHERE. I clear the log, cleared my browser cache, and did a ctrl-R refresh. And still, not a single Jar request on the Fiddler log. I even did a delayed write (with JS) of the applet tag after the page loaded, once all the Fiddler activity slowed down. The element gets written to the document (and I can see the 100x100 Java error window), but not a single request shows up on Fiddler. Any suggestions, before I go crawl into the corner and cry myself to sleep? EDIT: From the Java console, if I hit "l" (el) to "dump classloader list", I see something that looks like this: Live entry: key=http://localhost:55446/BaseWebSite/,http://localhost:55446/BaseWebSite/applet/myappliet.jar, http://localhost:55446/BaseWebSite/applet/applet_dependency.jar, refCount=1, threadGroup=sun.plugin2.applet.Applet2ThreadGroup[name=http://localhost:55446/BaseWebSite/-threadGroup,maxpri=4]

  Read the article

• JPanel components paint-time problem

  - by Tom Brito

  I'm having a problem that when my frame is shown (after a login dialog) the buttons are not on correct position, then in some miliseconds they go to the right position (the center of the panel with border layout). When I make a SSCCE, it works correct, but when I run my whole code I have this fast-miliseconds delay to the buttons to go to the correct place. Unfortunately, I can't post the whole code, but the method that shows the frame is: public void login(JComponent userView) { centerPanel.removeAll(); centerPanel.add(userView); centerPanel.revalidate(); centerPanel.repaint(); frame.setVisible(true); } What would cause this delay to the panel layout? (I'm running everything in the EDT) -- update In my machine, this SSCCE shows the layout problem in 2 of 10 times I run it: import java.awt.BorderLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class TEST { public static void main(String[] args) throws Exception { SwingUtilities.invokeAndWait(new Runnable() { @Override public void run() { System.out.println("Debug test..."); JPanel btnPnl = new JPanel(); btnPnl.add(new JButton("TEST")); JFrame f = new JFrame("TEST"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.getContentPane().setLayout(new BorderLayout()); f.getContentPane().add(btnPnl); f.pack(); f.setSize(800, 600); f.setVisible(true); System.out.println("End debug test!"); } }); } } The button first appers in the up-left, and then it goes to the center. Please, note that I'm understand, not just correct. Is it a java bug? --update OK, so the SSCCE don't show the problem with you that tried till now. Maybe it's my computer performance problem. But this don't answer the question, I still think Java Swing is creating new threads for make the layout behind the scenes.

  Read the article

• Designing a database file format

  - by RoliSoft

  I would like to design my own database engine for educational purposes, for the time being. Designing a binary file format is not hard nor the question, I've done it in the past, but while designing a database file format, I have come across a very important question: How to handle the deletion of an item? So far, I've thought of the following two options: Each item will have a "deleted" bit which is set to 1 upon deletion. Pro: relatively fast. Con: potentially sensitive data will remain in the file. 0x00 out the whole item upon deletion. Pro: potentially sensitive data will be removed from the file. Con: relatively slow. Recreating the whole database. Pro: no empty blocks which makes the follow-up question void. Con: it's a really good idea to overwrite the whole 4 GB database file because a user corrected a typo. I will sell this method to Twitter ASAP! Now let's say you already have a few empty blocks in your database (deleted items). The follow-up question is how to handle the insertion of a new item? Append the item to the end of the file. Pro: fastest possible. Con: file will get huge because of all the empty blocks that remain because deleted items aren't actually deleted. Search for an empty block exactly the size of the one you're inserting. Pro: may get rid of some blocks. Con: you may end up scanning the whole file at each insert only to find out it's very unlikely to come across a perfectly fitting empty block. Find the first empty block which is equal or larger than the item you're inserting. Pro: you probably won't end up scanning the whole file, as you will find an empty block somewhere mid-way; this will keep the file size relatively low. Con: there will still be lots of leftover 0x00 bytes at the end of items which were inserted into bigger empty blocks than they are. Rigth now, I think the first deletion method and the last insertion method are probably the "best" mix, but they would still have their own small issues. Alternatively, the first insertion method and scheduled full database recreation. (Probably not a good idea when working with really large databases. Also, each small update in that method will clone the whole item to the end of the file, thus accelerating file growth at a potentially insane rate.) Unless there is a way of deleting/inserting blocks from/to the middle of the file in a file-system approved way, what's the best way to do this? More importantly, how do databases currently used in production usually handle this?

  Read the article

• Can GPU capabilities impact virtual machine performance?

  - by Dave White

  While this many not seem like a programming question directly, it impacts my development activities and so it seems like it belongs here. It seems that more and more developers are turning to virtual environments for development activities on their computers, SharePoint development being a prime example. Also, as a trainer, I have virtual training environments for all of the classes that I teach. I recently purchased a new Dell E6510 to travel around with. It has the i7 620M (Dual core, HyperThreaded cpu running at 2.66GHz) and 8 GB of memory. Reading the spec sheet, it sounded like it would be a great laptop to carry around and run virtual machines on. Getting the laptop though, I've been pretty disappointed with the user experience of developing in a virtual machine. Giving the Virtual Machine 4 GB of memory, it was slow and I could type complete sentences and watch the VM "catchup". My company has training laptops that we provide for our classes. They are Dell Precision M6400 Intel Core 2 Duo P8700 running at 2.54Ghz with 8 GB of memory and the experience on this laptops is night and day compared to the E6510. They are crisp and you barely aware that you are running in a virtual environment. Since the E6510 should be faster in all categories than the M6400, I couldn't understand why the new laptop was slower, so I did a component by component comparison and the only place where the E6510 is less performant than the M6400 is the graphics department. The M6400 is running a nVidia FX 2700m GPU and the E6510 is running a nVidia 3100M GPU. Looking at benchmarks of the two GPUs suggest that the FX 2700M is twice as fast as the 3100M. http://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html 3100M = 111th (E6510) FX 2700m = 47th (Precision M6400) Radeon HD 5870 = 8th (Alienware) The host OS is Windows 7 64bit as is the guest OS, running in Virtual Box 3.1.8 with Guest Additions installed on the guest. The IDE being used in the virtual environment is VS 2010 Premium. So after that long setup, my question is: Is the GPU significantly impacting the virtual machine's performance or are there other factors that I'm not looking at that I can use to boost the vm's performance? Do we now have to consider GPU performance when purchasing laptops where we expect to use virtualized development environments? Thanks in advance. Cheers, Dave

  Read the article

• Question SpeechSynthesizer.SetOutputToAudioStream audio format problem

  - by Chris Kugler

  Hi, I'm currently working on an application which requires transmission of speech encoded to a specific audio format. System.Speech.AudioFormat.SpeechAudioFormatInfo synthFormat = new System.Speech.AudioFormat.SpeechAudioFormatInfo(System.Speech.AudioFormat.EncodingFormat.Pcm, 8000, 16, 1, 16000, 2, null); This states that the audio is in PCM format, 8000 samples per second, 16 bits per sample, mono, 16000 average bytes per second, block alignment of 2. When I attempt to execute the following code there is nothing written to my MemoryStream instance; however when I change from 8000 samples per second up to 11025 the audio data is written successfully. SpeechSynthesizer synthesizer = new SpeechSynthesizer(); waveStream = new MemoryStream(); PromptBuilder pbuilder = new PromptBuilder(); PromptStyle pStyle = new PromptStyle(); pStyle.Emphasis = PromptEmphasis.None; pStyle.Rate = PromptRate.Fast; pStyle.Volume = PromptVolume.ExtraLoud; pbuilder.StartStyle(pStyle); pbuilder.StartParagraph(); pbuilder.StartVoice(VoiceGender.Male, VoiceAge.Teen, 2); pbuilder.StartSentence(); pbuilder.AppendText("This is some text."); pbuilder.EndSentence(); pbuilder.EndVoice(); pbuilder.EndParagraph(); pbuilder.EndStyle(); synthesizer.SetOutputToAudioStream(waveStream, synthFormat); synthesizer.Speak(pbuilder); synthesizer.SetOutputToNull(); There are no exceptions or errors recorded when using a sample rate of 8000 and I couldn't find anything useful in the documentation regarding SetOutputToAudioStream and why it succeeds at 11025 samples per second and not 8000. I have a workaround involving a wav file that I generated and converted to the correct sample rate using some sound editing tools, but I would like to generate the audio from within the application if I can. One particular point of interest was that the SpeechRecognitionEngine accepts that audio format and successfully recognized the speech in my synthesized wave file... Update: Recently discovered that this audio format succeeds for certain installed voices, but fails for others. It fails specifically for LH Michael and LH Michelle, and failure varies for certain voice settings defined in the PromptBuilder.

  Read the article

• J2ME/Java: Referencing StringBuffer through Threads

  - by Jemuel Dalino

  This question might be long, but I want to provide much information. Overview: I'm creating a Stock Quotes Ticker app for Blackberry. But I'm having problems with my StringBuffer that contains an individual Stock information. Process: My app connects to our server via SocketConnection. The server sends out a formatted set of strings that contains the latest Stock trade. So whenever a new trade happens, the server will send out an individual Stock Quote of that trade. Through an InputStream I am able to read that information and place each character in a StringBuffer that is referenced by Threads. By parsing based on char3 I am able to determine a set of stock quote/information. char1 - to separate data char3 - means end of a stock quote/information sample stock quote format sent out by our server: stock_quote_name(char 1)some_data(char1)some_data(char1)(char3) My app then parses that stock quote to compare certain data and formats it how it will look like when displayed in the screen. When trades happen gradually(slow) the app works perfectly. However.. Problem: When trades happen too quickly and almost at the same time, My app is not able to handle the information sent efficiently. The StringBuffer has its contents combined with the next trade. Meaning Two stock information in one StringBuffer. field should be: Stock_quote_name some_data some_data sample of what's happening: Stock_quote_name some_data some_dataStock_quote_name some_data some_data here's my code for this part: while (-1 != (data = is.read())) { sb.append((char)data); while(3 != (data = is.read())) { sb.append((char)data); } UiApplication.getUiApplication().invokeLater(new Runnable() { public void run() { try { synchronized(UiApplication.getEventLock()) { SetStringBuffer(sb); DisplayStringBuffer(); RefreshStringBuffer(); } } catch (Exception e) { System.out.println("Error in setting stringbuffer: " + e.toString()); } } }); } public synchronized void DisplayStringBuffer() { try { //parse sb - string buffer ...... } catch(Exception ex) { System.out.println("error in DisplayStringBuffer(): " + ex.toString()); } } public synchronized void SetStringBuffer(StringBuffer dataBuffer) { this.sb =dataBuffer; System.out.println(sb); } public synchronized void RefreshStringBuffer() { this.sb.delete(0, this.sb.length()); } From what I can see, when trades happen very fast, The StringBuffer is not refreshed immediately and still has the contents of the previous trade, when i try to put new data. My Question is: Do you guys have any suggestion on how i can put data into the StringBuffer, without the next information being appended to the first content

  Read the article

• Rails controller method going to plural form

  - by Jty.tan

  I'm new to rails! Ok, I am trying to set up a user signup form. It is mapped as a singular resource in the routes map.resource :user And trying to create the user through the console works fine. the controller code for user's signup is as follows: def signup @user = User.new#(params[:user]) end def create @user = User.new(params[:user]) #debugger if request.post? if @user.save session[:user] = User.authenticate(@user.login, @user.password) flash[:message] = "Signup successful" redirect_to registries_path else flash[:warning] = "Signup unsuccessful" #redirect_to 'user/signup' end end end The signup view is as follows (and this is where i think something is going wrong) <% form_tag user_path do %> <p>User creation.</p> <p><%= error_messages_for 'user' %></p> <p> <label>Username:</label> <%= text_field_tag 'login', nil, :size => 20, :maxlength => 20 %> </p> <p> <label>Password:</label> <%= password_field_tag 'password', nil, :size => 20, :maxlength => 20 %> </p> <p> <label>Password confirmation:</label> <%= password_field_tag 'password_confirmation', nil, :size => 20, :maxlength => 20 %> </p> <p> <label>Email:</label> <%= text_field_tag 'email' %> </p> <p><%= submit_tag 'Signup' %></p> <% end %> Now, that page renders just fine. I've called the form on the "user_path" which is singular (i think?). But when I hit the submit button, it gives me an error saying that uninitialized constant UsersController the occurence of the error makes sense, since User is meant to be singular, so if it is trying to call the Users controller, it should be chucking an error. When I checked the server log, it shows this message: Processing ApplicationController#create (for 127.0.0.1 at 2010-05-08 16:26:14) [POST] Parameters: {"commit"=>"Signup", "password_confirmation"=>"[FILTERED]", "action"=>"create", "authenticity_token"=>"yOcHY+rMjaqmu9HS8EwnDqJKbc0Zxictc0y4dtD26ac=", "controller"=>"users", "login"=>"bob", "password"=>"[FILTERED]", "email"=>"[email protected]"} NameError (uninitialized constant UsersController): In the params, I can see that it is calling the "users" controller. But I'm not sure how to fix that, or what is causing it to call the "users" controller as opposed to the "user" controller. Any ideas? Thanks in advance!

  Read the article

• C++ template function specialization using TCHAR on Visual Studio 2005

  - by Eli

  I'm writing a logging class that uses a templatized operator<< function. I'm specializing the template function on wide-character string so that I can do some wide-to-narrow translation before writing the log message. I can't get TCHAR to work properly - it doesn't use the specialization. Ideas? Here's the pertinent code: // Log.h header class Log { public: template <typename T> Log& operator<<( const T& x ); template <typename T> Log& operator<<( const T* x ); template <typename T> Log& operator<<( const T*& x ); ... } template <typename T> Log& Log::operator<<( const T& input ) { printf("ref"); } template <typename T> Log& Log::operator<<( const T* input ) { printf("ptr"); } template <> Log& Log::operator<<( const std::wstring& input ); template <> Log& Log::operator<<( const wchar_t* input ); And the source file // Log.cpp template <> Log& Log::operator<<( const std::wstring& input ) { printf("wstring ref"); } template <> Log& Log::operator<<( const wchar_t* input ) { printf("wchar_t ptr"); } template <> Log& Log::operator<<( const TCHAR*& input ) { printf("tchar ptr ref"); } Now, I use the following test program to exercise these functions // main.cpp - test program int main() { Log log; log << "test 1"; log << L"test 2"; std::string test3( "test3" ); log << test3; std::wstring test4( L"test4" ); log << test4; TCHAR* test5 = L"test5"; log << test4; } Running the above tests reveals the following: // Test results ptr wchar_t ptr ref wstring ref ref Unfortunately, that's not quite right. I'd really like the last one to be "TCHAR", so that I can convert it. According to Visual Studio's debugger, the when I step in to the function being called in test 5, the type is wchar_t*& - but it's not calling the appropriate specialization. Ideas? I'm not sure if it's pertinent or not, but this is on a Windows CE 5.0 device.

  Read the article

• USB windows xp final USB access issues

  - by Lex Dean

  I basically understand you C++ people, Please do not get distracted because I'm writing in Delphi. I have a stable USB Listing method that accesses all my USB devices I get the devicepath, and this structure: TSPDevInfoData = packed record Size: DWORD; ClassGuid: TGUID; DevInst: DWORD; // DEVINST handle Reserved: DWord; end; I get my ProductID and VenderID successfully from my DevicePath Lists all USB devices connected to the computer at the time That enables me to access the registry data to each device in a stable way. What I'm lacking is a little direction Is friendly name able to be written inside the connected USB Micro chips by the firmware programmer? (I'm thinking of this to identify the device even further, or is this to help identify Bulk data transfer devices like memory sticks and camera's) Can I use SPDRP_REMOVAL_POLICY_OVERRIDE to some how reset these polices What else can I do with the registry details. Identifying when some one unplugs a device The program is using (in windows XP standard) I used a documented windows event that did not respond. Can I read a registry value to identify if its still connected? using CreateFileA (DevicePath) to send and receive data I have read when some one unplugs in the middle of a data transfer its difficult clearing resources. what can IoCreateDevice do for me and how does one use it for that task This two way point of connection status and system lock up situations is very concerning. Has some one read anything about this subject recently? My objectives are to 1. list connected USB devices identify a in development Micro Controller from everything else send and receive data in a stable and fast way to the limits of the controller No lock up's transferring data Note I'm not using any service packs I understand everything USB is in ANSI when windows xp is not and .Net is all about ANSI (what a waste of memory) I plan to continue this project into a .net at a later date as an addition. MSDN gives me Structures and Functions and what should link to what ok but say little to what they get used for. What is available in my language Delphi is way over priced that it needs a major price drop.

  Read the article

• Using empty row as default in a ComboBox with Style "DropDownList"?

  - by Pesche Helfer

  Hi board I am trying to write a method, that takes a ComboBox, a DataTable and a TextBox as arguments. The purpose of it is to filter the members displayed in the ComboBox according to the TextBox.Text. The DataTable contains the entire list of possible entries that will then be filtered. For filtering, I create a DataView of the DataTable, add a RowFilter and then bind this View to the ComboBox as DataSource. To prevent the user from typing into the ComboBox, I choose the DropDownStyle DropDownList. That’s working fine so far, except that the user should also be able to choose nothing / empty line. In fact, this should be the default member to be displayed (to prevent choosing a wrong member by accident, if the user clicks through the dialog too fast). I tried to solve this problem by adding a new Row to the view. While this works for some cases, the main issue here is that any DataTable can be passed to the method. If the DataTable contains columns that cannot be null and don’t contain a default value, I suppose I will raise an error by adding an empty row. A possibility would be to create a view that contains only the column that is defined as DisplayMember, and the one that is defined as ValueMember. Alas, this can’t be done with a view in C#. I would like to avoid creating a true copy of the DataTable at all cost, since who knows how big it will get with time. Do you have any suggestions how to get around this problem? Instead of a view, could I create an object containing two members and assign the DisplayMember and the ValueMember to these members? Would the members be passed as reference (what I hope) or would true copied be created (in which case it would not be a solution)? Thank you very much for your help! Best regards public static void ComboFilter(ComboBox cb, DataTable dtSource, TextBox filterTextBox) { cb.DropDownStyle = ComboBoxStyle.DropDownList; string displayMember = cb.DisplayMember; DataView filterView = new DataView(dtSource); filterView.AddNew(); filterView.RowFilter = displayMember + " LIKE '%" + filterTextBox.Text + "%'"; cb.DataSource = filterView; }

  Read the article

< Previous Page | 274 275 276 277 278 279 280 281 282 283 284 285  | Next Page >