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  • Problem adding subviews (UIButtons) to subclass of UIImageView

    - by samfu_1
    I'm adding a custom button/keypad to my application. Thus far, I have a UIImageView subclass that contains an animation that slides it from the bottom of the screen, and then back down when the user no longer needs it. I'm having trouble adding UIButtons to this UIImageView, however. Since this is a subclass of UIView, I'm attempting to add buttons to my view via the initWithFrame: method. (slideDown method is the added animation) in my UIImageView Subclass, I have a UIButton ivar object added: -(id)initWithFrame:(CGRect)frame { if (self = [super initWithFrame: frame]) { UIButton *button = [UIButton buttonWithType: UIButtonTypeRoundedRect]; button.frame = CGRectMake(16.0, 20.0, 50.0, 50.0); [button setTitle: @"Go" forState: UIControlStateNormal]; [button addTarget: self action: @selector(slideDown) forControlEvents: UIControlEventTouchUpInside]; self.button1 = button; [self addSubview: button1]; NSLog(@"Button added"); } return self; } In my view controller, I instantiate my UIIMageView Subclass in the -(void)viewDidLoad: method as follows: -(void)viewDidLoad { //other objects init'ed ButtonPad *customPad = [[ButtonPad alloc] initWithImage: [UIImage imageNamed: @"ButtonPad.png"]]; customPad.frame = CGRectMake(0.0, 480.0, 320.0, 300.0); self.buttonPad = customPad; [self.view addSubview: buttonPad]; [customPad release]; [super viewDidLoad]; } My current app allows the view to slide up and down off of the screen without any problems. However, the button never appears. I have also tried adding the button to my buttonPad object by instantiating & adding it as a subView to the buttonPad in my view controller file. This worked... but it didn't allow the button to function. I am wondering: A.) Is it appropriate to add buttons or any subview for that matter to the UIView initWithFrame: method or should I be adding these subviews as a subview to my buttonPad in the view Controller file? B.) Since I am creating a custom button/keypad, am i following a valid approach by using a normal UIViewController or should I be using something like a modal view Controller? ( I have little knowledge about these.)

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  • Haskell newbie on types

    - by garulfo
    I'm completely new to Haskell (and more generally to functional programming), so forgive me if this is really basic stuff. To get more than a taste, I try to implement in Haskell some algorithmic stuff I'm working on. I have a simple module Interval that implements intervals on the line. It contains the type data Interval t = Interval t t the helper function makeInterval :: (Ord t) => t -> t -> Interval t makeInterval l r | l <= r = Interval l r | otherwise = error "bad interval" and some utility functions about intervals. Here, my interest lies in multidimensional intervals (d-intervals), those objects that are composed of d intervals. I want to separately consider d-intervals that are the union of d disjoint intervals on the line (multiple interval) from those that are the union of d interval on d separate lines (track interval). With distinct algorithmic treatments in mind, I think it would be nice to have two distinct types (even if both are lists of intervals here) such as import qualified Interval as I -- Multilple interval newtype MInterval t = MInterval [I.Interval t] -- Track interval newtype TInterval t = TInterval [I.Interval t] to allow for distinct sanity checks, e.g. makeMInterval :: (Ord t) => [I.Interval t] -> MInterval t makeMInterval is = if foldr (&&) True [I.precedes i i' | (i, i') <- zip is (tail is)] then (MInterval is) else error "bad multiple interval" makeTInterval :: (Ord t) => [I.Interval t] -> TInterval t makeTInterval = TInterval I now get to the point, at last! But some functions are naturally concerned with both multiple intervals and track intervals. For example, a function order would return the number of intervals in a multiple interval or a track interval. What can I do? Adding -- Dimensional interval data DInterval t = MIntervalStuff (MInterval t) | TIntervalStuff (TInterval t) does not help much, since, if I understand well (correct me if I'm wrong), I would have to write order :: DInterval t -> Int order (MIntervalStuff (MInterval is)) = length is order (TIntervalStuff (TInterval is)) = length is and call order as order (MIntervalStuff is) or order (TIntervalStuff is) when is is a MInterval or a TInterval. Not that great, it looks odd. Neither I want to duplicate the function (I have many functions that are concerned with both multiple and track intevals, and some other d-interval definitions such as equal length multiple and track intervals). I'm left with the feeling that I'm completely wrong and have missed some important point about types in Haskell (and/or can't forget enough here about OO programming). So, quite a newbie question, what would be the best way in Haskell to deal with such a situation? Do I have to forget about introducing MInterval and TInterval and go with one type only? Thanks a lot for your help, Garulfo

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  • Can someone please help, I cant get this simple scolling feature

    - by localgamer
    I want to be able to have many button and objects in my project but they all wont fit on the screen at once so i would like the user to be able to scroll down and have more appear but i cant get it to work. I tried using ScrollView but it always throws me errors. Here is what I have so far. Please, any help would be great. <?xml version="1.0" encoding="utf-8"?> <AbsoluteLayout android:id="@+id/widget0" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Hello World, tipcalc" /> <TextView android:id="@+id/widget28" android:layout_width="99px" android:layout_height="17px" android:text="Monthly Income" android:layout_x="40px" android:layout_y="32px" > </TextView> <TextView android:id="@+id/widget29" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Cable" android:layout_x="40px" android:layout_y="82px" > </TextView> <TextView android:id="@+id/widget30" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Internet" android:layout_x="40px" android:layout_y="132px" > </TextView> <TextView android:id="@+id/widget33" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Total To Pay" android:layout_x="40px" android:layout_y="302px" > </TextView> <Button android:id="@+id/btncalculate" android:layout_width="87px" android:layout_height="wrap_content" android:text="Calculate" android:layout_x="40px" android:layout_y="182px" > </Button> <Button android:id="@+id/btnreset" android:layout_width="86px" android:layout_height="wrap_content" android:text="Reset" android:layout_x="140px" android:layout_y="182px" > </Button> <EditText android:id="@+id/Monthly" android:layout_width="wrap_content" android:layout_height="35px" android:text="100" android:textSize="18sp" android:layout_x="200px" android:layout_y="22px" > </EditText> <EditText android:id="@+id/Internet" android:layout_width="51px" android:layout_height="36px" android:text="10" android:textSize="18sp" android:layout_x="200px" android:layout_y="72px" > </EditText> <EditText android:id="@+id/Cable" android:layout_width="wrap_content" android:layout_height="39px" android:text="1" android:textSize="18sp" android:layout_x="200px" android:layout_y="122px" > </EditText> <TextView android:id="@+id/txttotal" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="" android:layout_x="200px" android:layout_y="302px" > </TextView> </AbsoluteLayout>

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  • IronPython and Nodebox in C#

    - by proxylittle
    My plan: I'm trying to setup my C# project to communicate with Nodebox to call a certain function which populates a graph and draws it in a new window. Current situation: [fixed... see Update2] I have already included all python-modules needed, but im still getting a Library 'GL' not found it seems that the pyglet module needs a reference to GL/gl.h, but can't find it due to IronPython behaviour. Requirement: The project needs to stay as small as possible without installing new packages. Thats why i have copied all my modules into the project-folder and would like to keep it that or a similar way. My question: Is there a certain workaround for my problem or a fix for the library-folder missmatch. Have read some articles about Tao-Opengl and OpenTK but can't find a good solution. Update1: Updated my sourcecode with a small pyglet window-rendering example. Problem is in pyglet and referenced c-Objects. How do i include them in my c# project to be called? No idea so far... experimenting alittle now. Keeping you updated. SampleCode C#: ScriptRuntimeSetup setup = Python.CreateRuntimeSetup(null); ScriptRuntime runtime = new ScriptRuntime(setup); ScriptEngine engine = Python.GetEngine(runtime); ScriptSource source = engine.CreateScriptSourceFromFile("test.py"); ScriptScope scope = engine.CreateScope(); source.Execute(scope); SampleCode Python (test.py): from nodebox.graphics import * from nodebox.graphics.physics import Vector, Boid, Flock, Obstacle flock = Flock(50, x=-50, y=-50, width=700, height=400) flock.sight(80) def draw(canvas): canvas.clear() flock.update(separation=0.4, cohesion=0.6, alignment=0.1, teleport=True) for boid in flock: push() translate(boid.x, boid.y) scale(0.5 + boid.depth) rotate(boid.heading) arrow(0, 0, 15) pop() canvas.size = 600, 300 def main(canvas): canvas.run(draw) Update2: Line 139 [pyglet/lib.py] sys.platform is not win32... there was the error. Fixed it by just using the line: from pyglet.gl.lib_wgl import link_GL, link_GLU, link_WGL Now the following Error: 'module' object has no attribute '_getframe' Kind of a pain to fix it. Updating with results... Update3: Fixed by adding following line right after first line in C#-Code: setup.Options["Frames"] = true; Current Problem: No module named unicodedata, but in Python26/DLLs is only a *.pyd file`. So.. how do i implement it now?!

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  • .NET RegEx "Memory Leak" investigation

    - by Kevin Pullin
    I recently looked into some .NET "memory leaks" (i.e. unexpected, lingering GC rooted objects) in a WinForms app. After loading and then closing a huge report, the memory usage did not drop as expected even after a couple of gen2 collections. Assuming that the reporting control was being kept alive by a stray event handler I cracked open WinDbg to see what was happening... Using WinDbg, the !dumpheap -stat command reported a large amount of memory was consumed by string instances. Further refining this down with the !dumpheap -type System.String command I found the culprit, a 90MB string used for the report, at address 03be7930. The last step was to invoke !gcroot 03be7930 to see which object(s) were keeping it alive. My expectations were incorrect - it was not an unhooked event handler hanging onto the reporting control (and report string), but instead it was held on by a System.Text.RegularExpressions.RegexInterpreter instance, which itself is a descendant of a System.Text.RegularExpressions.CachedCodeEntry. Now, the caching of Regexs is (somewhat) common knowledge as this helps to reduce the overhead of having to recompile the Regex each time it is used. But what then does this have to do with keeping my string alive? Based on analysis using Reflector, it turns out that the input string is stored in the RegexInterpreter whenever a Regex method is called. The RegexInterpreter holds onto this string reference until a new string is fed into it by a subsequent Regex method invocation. I'd expect similar behaviour by hanging onto Regex.Match instances and perhaps others. The chain is something like this: Regex.Split, Regex.Match, Regex.Replace, etc Regex.Run RegexScanner.Scan (RegexScanner is the base class, RegexInterpreter is the subclass described above). The offending Regex is only used for reporting, rarely used, and therefore unlikely to be used again to clear out the existing report string. And even if the Regex was used at a later point, it would probably be processing another large report. This is a relatively significant problem and just plain feels dirty. All that said, I found a few options on how to resolve, or at least work around, this scenario. I'll let the community respond first and if no takers come forward I will fill in any gaps in a day or two.

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  • Connecting to MSSQL 2008 from Java

    - by Xinus
    I am trying to connect to MSSQL 2008 server from Java here is a program import java.sql.*; public class connectURL { public static void main(String[] args) { // Create a variable for the connection string. String connectionUrl = "jdbc:sqlserver://localhost/SQLEXPRESS/Databases/HelloWorld:1433;";// + //"databaseName=HelloWorld;integratedSecurity=true;"; // Declare the JDBC objects. Connection con = null; Statement stmt = null; ResultSet rs = null; try { // Establish the connection. Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); con = DriverManager.getConnection(connectionUrl); // Create and execute an SQL statement that returns some data. String SQL = "SELECT TOP 10 * FROM Person.Contact"; stmt = con.createStatement(); rs = stmt.executeQuery(SQL); // Iterate through the data in the result set and display it. while (rs.next()) { System.out.println(rs.getString(4) + " " + rs.getString(6)); } } // Handle any errors that may have occurred. catch (Exception e) { e.printStackTrace(); } finally { if (rs != null) try { rs.close(); } catch(Exception e) {} if (stmt != null) try { stmt.close(); } catch(Exception e) {} if (con != null) try { con.close(); } catch(Exception e) {} } } } But it shows error as com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host localhost/SQLEXPRESS/Databases/HelloWorld, port 1433 has failed. Error: "null. Verify the connection properties, check that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port, and that no firewall is blocking TCP connections to the port.". at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:170) at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1049) at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:833) at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:716) at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:841) at java.sql.DriverManager.getConnection(Unknown Source) at java.sql.DriverManager.getConnection(Unknown Source) at connectURL.main(connectURL.java:43) I have given followed all the instructions as given in http://teamtutorials.com/database-tutorials/configuring-and-creating-a-database-in-ms-sql-2008 What can be the problem ?

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  • Design question for WinForms (C#) app, using Entity Framework

    - by cdotlister
    I am planning on writing a small home budget application for myself, as a learning excercise. I have built my database (SQL Server), and written a small console application to interact with it, and test out scenarios on my database. Once I am happy, my next step would be to start building the application - but I am already wondering what the best/standard design would be. I am palnning on using Entity Framework for handling my database entities... then linq to sql/objects for getting the data, all running under a WinForms (for now) application. My plan (I've never used EF... and most of my development background is Web apps) is to have my database... with Entity Framework in it's own project.. which has the connection to the database. This project would expose methods such as 'GetAccount()', 'GetAccount(int accountId)' etc. I'd then have a service project that references my EF project. And on top of that, my GUI project, which makes the calls to my service project. But I am stuck. Lets say I have a screen that displays a list of Account types (Debit, Credit, Loan...). Once I have selected one, the next drop down shows a list of accounts I have that suite that account type. So, my OnChange event on my DropDown on the account type control will make a call to the serviceLayer project, 'GetAccountTypes()', and I would expect back a List< of Account Types. However, the AccountType object ... what is that? That can't be the AccountType object from my EF project, as my GUI project doesn't have reference to it. Would I have to have some sort of Shared Library, shared between my GUI and my Service project, with a custom built AccountType object? The GUI can then expect back a list of these. So my service layer would have a method: public List<AccountType> GetAccountTypes() That would then make a call to a custom method in my EF project, which would probably be the same as the above method, except, it returns an list of EF.Data.AccountType (The Entity Framework generated Account Type object). The method would then have the linq code to get the data as I want it. Then my service layer will get that object, and transform it unto my custom AccountType object, and return it to the GUI. Does that sound at all like a good plan?

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  • Does my fat-client application belong in the MVC pattern?

    - by boatingcow
    The web-based application I’m currently working on is growing arms and legs! It’s basically an administration system which helps users to keep track of bookings, user accounts, invoicing etc. It can also be accessed via a couple of different websites using a fairly crude API. The fat-client design loosely follows the MVC pattern (or perhaps MVP) with a php/MySQL backend, Front Controller, several dissimilar Page Controllers, a liberal smattering of object-oriented and procedural Models, a confusing bunch of Views and templates, some JavaScripts, CSS files and Flash objects. The programmer in me is a big fan of the principle of “Separation of Concerns” and on that note, I’m currently trying to figure out the best way to separate and combine the various concerns as the project grows and more people contribute to it. The problem we’re facing is that although JavaScript (or Flash with ActionScript) is normally written with the template, hence part of the View and decoupled from the Controller and Model, we find that it actually encompasses the entire MVC pattern... Swap an image with an onmouseover event - that’s Behaviour. Render a datagrid - we’re manipulating the View. Send the result of reordering a list via AJAX - now we’re in Control. Check a form field to see if an email address is in a valid format - we’re consulting the Model. Is it wise to let the database people write up the validation Model with jQuery? Can the php programmers write the necessary Control structures in JavaScript? Can the web designers really write a functional AJAX form for their View? Should there be a JavaScript overlord for every project? If the MVC pattern could be applied to the people instead of the code, we would end up with this: Model - the database boffins - “SELECT * FROM mind WHERE interested IS NULL” Control - pesky programmers - “class Something extends NothingAbstractClass{…}” View - traditionally the domain of the graphic/web designer - “” …and a new layer: Behaviour - interaction and feedback designer - “CSS3 is the new black…” So, we’re refactoring and I’d like to stick to best practice design, but I’m not sure how to proceed. I don’t want to reinvent the wheel, so would anyone have any hints or tips as to what pattern I should be looking at or any code samples from someone who’s already done the dirty work? As the programmer guy, how can I rewrite the app for backend and front end whilst keeping the two separate? And before you ask, yes I’ve looked at Zend, CodeIgnitor, Symfony, etc., and no, they don’t seem to cross the boundary between server logic and client logic!

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  • Drawing performance with CGImageCreateWithJPEGDataProvider?

    - by Rnegi
    I've actually curious about this for the iPhone. I am getting an MJPEG stream from a server and trying to render it natively on the iphone (without the use of safari class). Reasons for this is because the safari class while CAN render MJPEG natively, does not do so at the framerate I would like. So I tried drawing it natively, but I've come up with performance issues, namely a syncing issue between what I'm getting from the server and what I am able to draw onto the screen of the phone. (There should be a little lag, but the drift gets really bad, which is what I want to avoid). So I have a connection set up to my server and I do get the JPEGS. It's just data I insert into a NSMutableArray buffer CFMutableDataRef _t_data_ref = (CFMutableDataRef)[_buffer_array objectAtIndex:0]; //CGDataProviderRef imgDataProvider = CGDataProviderCreateWithCFData (_cf_buffer_data); CGDataProviderRef imgDataProvider = CGDataProviderCreateWithCFData(_t_data_ref); CGImageRef image = CGImageCreateWithJPEGDataProvider(imgDataProvider, NULL, true, kCGRenderingIntentDefault); CGImageRef imgRef = image; CGContextDrawImage(context, CGRectMake(0, 17, 380, 285), imgRef); CGImageRelease(image); CGDataProviderRelease(imgDataProvider); please note this is the gist of my code, but it should summarize what I am trying to accomplish with regards to drawing. Also in order to get the framerate in sync, I had to detach a separate thread that sleeps X seconds and calls [self setNeedsDisplay]. NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; // Top-level pool while(1) { //[NSThread sleepForTimeInterval:TIMER_REFRESH_VALUE]; //sleep(unsigned int ); usleep(MICRO_REFRESH_VALUE); if ([_buffer_array count] > 10) { //NSLog(@"stuff %d", [_buffer_array count]); //[self setNeedsDisplay]; [self performSelectorOnMainThread:@selector(setNeedsDisplay) withObject:nil waitUntilDone:NO]; } } [pool release]; // Release the objects in the pool. My buffer of jpeg data actually fills up quite quick, but I can't seem to actually consume what i'm getting at the same rate, actually much slower. Are there any documents that can describe what kind of performance tuning I can do to make it go faster when rendering the JPEG to the screen? Or am I kind of stuck here? Thanks!

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  • Crazy VS Designer Errors

    - by BlueRaja
    Here's a strange one. After renaming a class, one of my forms began giving me errors in the designer, refusing to open. Funny thing is, the form worked just fine when I ran the program. I began reverting my changes to deduce the problem. I have now reverted completely back to the last commit - in which I know the form was working in the designer - cleaned the solution, and deleted the bin/ and obj/ folders, as well as the *.suo file for good measure. The form still does not display in designer. Here are the errors it gives: Could not find 'MyNamespace.MyControl'. Please make sure that the assembly that contains this type is referenced. If this type is a part of your development project, make sure that the project has been successfully built. The variable 'myControl1' is either undeclared or was never assigned. The variable is both declared and assigned, and MyControl builds fine (again, the form works fine when the program is actually run). Stranger still, if I try to create a new form and drag a MyControl onto it, I get this Entity-Framework error: Failed to create component 'MyControl'. The error message follows: 'System.ArgumentException: The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid. at System.Data.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) at System.Data.EntityClient.EntityConnection..ctor(String connectionString) at System.Data.Objects.ObjectContect.CreateEntityConnection(String connectionString) etc. etc. There is nothing wrong with my connection string: it worked before, and, again, it works when I actually run the program (the control already exists on the old form from the previous commit). Any ideas whatsoever? I am completely at a loss. [Edit] The only significant code: MyControl.cs public MyControl() { _entities = new MyEFEntities(); //Entity-framework generated class } MyForm.Designer.cs private void InitializeComponent() { this.myControl1 = new MyNamespace.MyControl(); ... this.Controls.Add(this.myControl1); } MyEFDatabase.Designer.cs public MyEFEntities() : base("name=MyEFEntities", "MyEFEntities") { ... } App.Config <connectionStrings> <add name="MyEFEntities" connectionString="metadata=res://*/MyEFDatabase.csdl|res://*/MyEFDatabase.ssdl|res://*/MyEFDatabase.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=MyDatabaseServer;Initial Catalog=MyDatabase;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" /> </connectionStrings> I've tried the "replace &quot; with '" trick - didn't help. [Edit2] It is happening to new projects also, but not immediately. Only after fiddling around a bit (it has something to do with adding a many-to-one relationship that EF did not figure out on its own), but I can't figure out the exact steps to reproduce.

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  • Global Entity Framework Context in WPF Application

    - by OffApps Cory
    Good day, I am in the middle of development of a WPF application that is using Entity Framework (.NET 3.5). It accesses the entities in several places throughout. I am worried about consistency throughout the application in regard to the entities. Should I be instancing separate contexts in my different views, or should I (and is a a good way to do this) instance a single context that can be accessed globally? For instance, my entity model has three sections, Shipments (with child packages and further child contents), Companies/Contacts (with child addresses and telephones), and disk specs. The Shipments and EditShipment views access the DiskSpecs, and the OptionsView manages the DiskSpecs (Create, Edit, Delete). If I edit a DiskSpec, I have to have something in the ShipmentsView to retrieve the latest specs if I have separate contexts right? If it is safe to have one overall context from which the rest of the app retrieves it's objects, then I imagine that is the way to go. If so, where would that instance be put? I am using VB.NET, but I can translate from C# pretty good. Any help would be appreciated. I just don't want one of those applications where the user has to hit reload a dozen times in different parts of the app to get the new data. Update: OK so I have changed my app as follows: All contexts are created in Using Blocks to dispose of them after they are no longer needed. When loaded, all entities are detatched from context before it is disposed. A new property in the MainViewModel (ContextUpdated) raises an event that all of the other ViewModels subscribe to which runs that ViewModels RefreshEntities method. After implementing this, I started getting errors saying that an entity can only be referenced by one ChangeTracker at a time. Since I could not figure out which context was still referencing the entity (shouldn't be any context right?) I cast the object as IEntityWithChangeTracker, and set SetChangeTracker to nothing (Null). This has let to the current problem: When I Null the changeTracker on the Entity, and then attach it to a context, it loses it's changed state and does not get updated to the database. However if I do not null the change tracker, I can't attach. I have my own change tracking code, so that is not a problem. My new question is, how are you supposed to do this. A good example Entity query and entity save code snipped would go a long way, cause I am beating my head in trying to get what I once thought was a simple transaction to work. Any help would elevate you to near god-hood.

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  • Sockets server design advice

    - by Rob
    We are writing a socket server in c# and need some advice on the design. Background: Clients (from mobile devices) connect to our server app and we leave their socket open so we can send data back down to them whenever we need to. The amount of data varies but we generally send/receive data from each client every few seconds, so it's quite intensive. The amount of simultaneous connections can range from 50-500 (and more in the future). We have already written a server app using async sockets and it works, however we've come across some stumbling blocks and we need to make sure that what we're doing is correct. We have a collection which holds our client states (we have no socket/connection pool at the moment, should we?). Each time a client connects we create a socket and then wait for them to send us some data and in receiveCallBack we add their clientstate object to our connections dictionary (once we have verified who they are). When a client object then signs off we shutdown their socket and then close it as well as remove them from our collection of clients dictionary. Presumably everything happens in the right order, everything works as expected. However, almost everyday it stops accepting connections, or so we think, either that or it connects but doesn't actually do anything past that and we can't work out why it's just stopping. There are few things that we'r'e unsure about 1) Should we be creating some kind of connection pool as opposed to just a dictionary of client sockets 2) What happens to the sockets that connect but then don't get added to our dictionary, they just linger around in memory doing nothing, should we create ANOTHER dictionary that holds the sockets as soon as they are created? 3) What's the best way of finding if clients are no longer connected? We've read some many methods but we're not sure of the best one to use, send data or read data, if so how? 4) If we loop through the connections dictonary to check for disposed clients, should we be locking the dictionary, if so how does this affect other clients objects trying to use it at the same time, will it throw an error or just wait? 5) We often get disposedSocketException within ReceiveCallBack method at random times, does this mean we are safe to remove that socket from the collection? We can't seem to find any production type examples which show any of this working. Any advice would be greatly received

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  • NSXMLParser Memory Allocation Efficiency for the iPhone

    - by Staros
    Hello, I've recently been playing with code for an iPhone app to parse XML. Sticking to Cocoa, I decided to go with the NSXMLParser class. The app will be responsible for parsing 10,000+ "computers", all which contain 6 other strings of information. For my test, I've verified that the XML is around 900k-1MB in size. My data model is to keep each computer in an NSDictionary hashed by a unique identifier. Each computer is also represented by a NSDictionary with the information. So at the end of the day, I end up with a NSDictionary containing 10k other NSDictionaries. The problem I'm running into isn't about leaking memory or efficient data structure storage. When my parser is done, the total amount of allocated objects only does go up by about 1MB. The problem is that while the NSXMLParser is running, my object allocation is jumping up as much as 13MB. I could understand 2 (one for the object I'm creating and one for the raw NSData) plus a little room to work, but 13 seems a bit high. I can't imaging that NSXMLParser is that inefficient. Thoughts? Code... The code to start parsing... NSXMLParser *parser = [[NSXMLParser alloc] initWithData: data]; [parser setDelegate:dictParser]; [parser parse]; output = [[dictParser returnDictionary] retain]; [parser release]; [dictParser release]; And the parser's delegate code... -(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict { if(mutableString) { [mutableString release]; mutableString = nil; } mutableString = [[NSMutableString alloc] init]; } -(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { if(self.mutableString) { [self.mutableString appendString:string]; } } -(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { if([elementName isEqualToString:@"size"]){ //The initial key, tells me how many computers returnDictionary = [[NSMutableDictionary alloc] initWithCapacity:[mutableString intValue]]; } if([elementName isEqualToString:hashBy]){ //The unique identifier if(mutableDictionary){ [mutableDictionary release]; mutableDictionary = nil; } mutableDictionary = [[NSMutableDictionary alloc] initWithCapacity:6]; [returnDictionary setObject:[NSDictionary dictionaryWithDictionary:mutableDictionary] forKey:[NSMutableString stringWithString:mutableString]]; } if([fields containsObject:elementName]){ //Any of the elements from a single computer that I am looking for [mutableDictionary setObject:mutableString forKey:elementName]; } } Everything initialized and released correctly. Again, I'm not getting errors or leaking. Just inefficient. Thanks for any thoughts!

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  • Retrieving Data related to a top-level object from parse.com using PHP

    - by Albeert Tw
    I am retrieve related data using parse.com and PHP I get the top-leve object without problems but I can't access related data. ([myRelation] => stdClass Object ( [__type] => Relation [className] => other)) Please refer to my code below: $className = "myClass"; $url = 'https://api.parse.com/1/classes/' . $className; $appId = 'xxxxxx'; $restKey = 'xxxxxxx'; $relatedParams = urlencode('include=people'); $rest = curl_init(); curl_setopt($rest, CURLOPT_SSL_VERIFYPEER, false); curl_setopt($rest, CURLOPT_URL, $url .'/io1GzkzErH/'.$relatedParams); curl_setopt($rest, CURLOPT_HTTPGET, true); curl_setopt($rest, CURLOPT_RETURNTRANSFER, true); curl_setopt($rest, CURLOPT_HTTPHEADER, array("X-Parse-Application-Id: " . $appId, "X-Parse-REST-API-Key: " . $restKey, "Content-Type: application/json")); $response = curl_exec($rest); echo $response; I want to see related objects into myRelation. Current answer is: I get this answer: stdClass Object ( [Altres] => loremipsum. [Cartell] => stdClass Object ( [__type] => File [name] => f29efff4-5db1-451a-ab42-7569fbb955a7-cartell.jpg [url] => loremipsum.jpg ) [CartellURL] => [Categoria] => Comedia [Durada] => 120min [Estat] => Al teatre [Final] => stdClass Object ( [__type] => Date [iso] => 2014-06-18T22:00:00.000Z ) [Inici] => stdClass Object ( [__type] => Date [iso] => 2014-04-25T22:00:00.000Z ) [Nom] => Losers [Prioritat] => 0 [Sala] => loremipsum [Sinopsis] => loremipsum [TrailerURL] => loremipsum.com [URLEntrada] => loremipsum.com [URLProductora] => http://www.loremipsum.com [Visible] => 1 [createdAt] => 2014-05-20T12:01:06.094Z [objectId] => io1GzkzErH [people] => stdClass Object ( [__type] => Relation [className] => persones ) [updatedAt] => 2014-05-20T12:07:22.758Z ) loremipsum But I need to know what are in [people] = stdClass Object ( [__type] = Relation [className] = persones )

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  • Stringtemplate: is it ok to Apply Templates, in which HashMap uses, To Multi-Valued Attributes

    - by user1071830
    There is two template in my .stg file, and both of them apply on multi-value a HashMap. The HashMap is employed as an injected object. And I need those instance of HashMap can be injected for many times. My trouble is, when I switch to another template, ANTLR seems to consider the second HashMap as a List -- multipul objects and null value. Part of my .stg file shows as follows: tpl_hash(BAR, FOO) ::= << <FOO:foo(); separator="\n"> <BAR:bar(); separator="\n"> >> foo(nn) ::= << foo: <nn.name; null="NULL"> . <nn.national; null="NULL"> >> bar(mm) ::= << bar: <mm.name> @ <mm.national> >> Part of my .g file shows: HashMap hm = new HashMap(); hm.put("name", $name.text); hm.put("national", "German"); tpl_hash.add("FOO",new HashMap(hm)); HashMap hm2 = new HashMap(); hm2.put("name", $name.text); hm2.put("national", "German"); tpl_hash.add("BAR",new HashMap(hm2)); The result I expect is : bar: Kant @ German foo: Russell @ England But, I got: foo: NULL . NULL foo: NULL . NULL bar: @ bar: @ If we replace BAR with FOO, as is, keeping FOO and BAR with identical template, the output is right, like the following. bar: Russell @ German bar: Russell @ German In docs, "synchronized ST add (String name, Object value) in org.stringtemplate.v4.ST" said: "If you send in a List and then inject a single value element, add() copies original list and adds the new value." What about a HashMap? Does ANTLR consider the HashMap, key/value pair access, an object purposely, as a List and as multi-value injected by mistake? Thanks a lot in advance.

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  • Optimizing multiple dispatch notification algorithm in C#?

    - by Robert Fraser
    Sorry about the title, I couldn't think of a better way to describe the problem. Basically, I'm trying to implement a collision system in a game. I want to be able to register a "collision handler" that handles any collision of two objects (given in either order) that can be cast to particular types. So if Player : Ship : Entity and Laser : Particle : Entity, and handlers for (Ship, Particle) and (Laser, Entity) are registered than for a collision of (Laser, Player), both handlers should be notified, with the arguments in the correct order, and a collision of (Laser, Laser) should notify only the second handler. A code snippet says a thousand words, so here's what I'm doing right now (naieve method): public IObservable<Collision<T1, T2>> onCollisionsOf<T1, T2>() where T1 : Entity where T2 : Entity { Type t1 = typeof(T1); Type t2 = typeof(T2); Subject<Collision<T1, T2>> obs = new Subject<Collision<T1, T2>>(); _onCollisionInternal += delegate(Entity obj1, Entity obj2) { if (t1.IsAssignableFrom(obj1.GetType()) && t2.IsAssignableFrom(obj2.GetType())) obs.OnNext(new Collision<T1, T2>((T1) obj1, (T2) obj2)); else if (t1.IsAssignableFrom(obj2.GetType()) && t2.IsAssignableFrom(obj1.GetType())) obs.OnNext(new Collision<T1, T2>((T1) obj2, (T2) obj1)); }; return obs; } However, this method is quite slow (measurable; I lost ~2 FPS after implementing this), so I'm looking for a way to shave a couple cycles/allocation off this. I thought about (as in, spent an hour implementing then slammed my head against a wall for being such an idiot) a method that put the types in an order based on their hash code, then put them into a dictionary, with each entry being a linked list of handlers for pairs of that type with a boolean indication whether the handler wanted the order of arguments reversed. Unfortunately, this doesn't work for derived types, since if a derived type is passed in, it won't notify a subscriber for the base type. Can anyone think of a way better than checking every type pair (twice) to see if it matches? Thanks, Robert

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  • How to eager load sibling data using LINQ to SQL?

    - by Scott
    The goal is to issue the fewest queries to SQL Server using LINQ to SQL without using anonymous types. The return type for the method will need to be IList<Child1>. The relationships are as follows: Parent Child1 Child2 Grandchild1 Parent Child1 is a one-to-many relationship Child1 Grandchild1 is a one-to-n relationship (where n is zero to infinity) Parent Child2 is a one-to-n relationship (where n is zero to infinity) I am able to eager load the Parent, Child1 and Grandchild1 data resulting in one query to SQL Server. This query with load options eager loads all of the data, except the sibling data (Child2): DataLoadOptions loadOptions = new DataLoadOptions(); loadOptions.LoadWith<Child1>(o => o.GrandChild1List); loadOptions.LoadWith<Child1>(o => o.Parent); dataContext.LoadOptions = loadOptions; IQueryable<Child1> children = from child in dataContext.Child1 select child; I need to load the sibling data as well. One approach I have tried is splitting the query into two LINQ to SQL queries and merging the result sets together (not pretty), however upon accessing the sibling data it is lazy loaded anyway. Adding the sibling load option will issue a query to SQL Server for each Grandchild1 and Child2 record (which is exactly what I am trying to avoid): DataLoadOptions loadOptions = new DataLoadOptions(); loadOptions.LoadWith<Child1>(o => o.GrandChild1List); loadOptions.LoadWith<Child1>(o => o.Parent); loadOptions.LoadWith<Parent>(o => o.Child2List); dataContext.LoadOptions = loadOptions; IQueryable<Child1> children = from child in dataContext.Child1 select child; exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=1 exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=2 exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=3 exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=4 I've also written LINQ to SQL queries to join in all of the data in hopes that it would eager load the data, however when the LINQ to SQL EntitySet of Child2 or Grandchild1 are accessed it lazy loads the data. The reason for returning the IList<Child1> is to hydrate business objects. My thoughts are I am either: Approaching this problem the wrong way. Have the option of calling a stored procedure? My organization should not be using LINQ to SQL as an ORM? Any help is greatly appreciated. Thank you, -Scott

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  • Problem in running boost eample blocking_udp_echo_client on MacOSX

    - by n179911
    I am trying to run blocking_udp_echo_client on MacOS X http://www.boost.org/doc/libs/1_35_0/doc/html/boost_asio/example/echo/blocking_udp_echo_client.cpp I run it with argument 'localhost 9000' But the program crashes and this is the line in the source which crashes: `udp::socket s(io_service, udp::endpoint(udp::v4(), 0));' this is the stack trace: #0 0x918c3e42 in __kill #1 0x918c3e34 in kill$UNIX2003 #2 0x9193623a in raise #3 0x91942679 in abort #4 0x940d96f9 in __gnu_debug::_Error_formatter::_M_error #5 0x0000e76e in __gnu_debug::_Safe_iterator::op_base* , __gnu_debug_def::list::op_base*, std::allocator::op_base* ::_Safe_iterator at safe_iterator.h:124 #6 0x00014729 in boost::asio::detail::hash_map::op_base*::bucket_type::bucket_type at hash_map.hpp:277 #7 0x00019e97 in std::_Construct::op_base*::bucket_type, boost::asio::detail::hash_map::op_base*::bucket_type at stl_construct.h:81 #8 0x0001a457 in std::__uninitialized_fill_n_aux::op_base*::bucket_type*, __gnu_norm::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type , unsigned long, boost::asio::detail::hash_map::op_base*::bucket_type at stl_uninitialized.h:194 #9 0x0001a4e1 in std::uninitialized_fill_n::op_base*::bucket_type*, __gnu_norm::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type , unsigned long, boost::asio::detail::hash_map::op_base*::bucket_type at stl_uninitialized.h:218 #10 0x0001a509 in std::__uninitialized_fill_n_a::op_base*::bucket_type*, __gnu_norm::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type , unsigned long, boost::asio::detail::hash_map::op_base*::bucket_type, boost::asio::detail::hash_map::op_base*::bucket_type at stl_uninitialized.h:310 #11 0x0001aa34 in __gnu_norm::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type ::_M_fill_insert at vector.tcc:365 #12 0x0001acda in __gnu_norm::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type ::insert at stl_vector.h:658 #13 0x0001ad81 in __gnu_norm::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type ::resize at stl_vector.h:427 #14 0x0001ae3a in __gnu_debug_def::vector::op_base*::bucket_type, std::allocator::op_base*::bucket_type ::resize at vector:169 #15 0x0001b7be in boost::asio::detail::hash_map::op_base*::rehash at hash_map.hpp:221 #16 0x0001bbeb in boost::asio::detail::hash_map::op_base*::hash_map at hash_map.hpp:67 #17 0x0001bc74 in boost::asio::detail::reactor_op_queue::reactor_op_queue at reactor_op_queue.hpp:42 #18 0x0001bd24 in boost::asio::detail::kqueue_reactor::kqueue_reactor at kqueue_reactor.hpp:86 #19 0x0001c000 in boost::asio::detail::service_registry::use_service at service_registry.hpp:109 #20 0x0001c14d in boost::asio::use_service at io_service.ipp:195 #21 0x0001c26d in boost::asio::detail::reactive_socket_service ::reactive_socket_service at reactive_socket_service.hpp:111 #22 0x0001c344 in boost::asio::detail::service_registry::use_service at service_registry.hpp:109 #23 0x0001c491 in boost::asio::use_service at io_service.ipp:195 #24 0x0001c4d5 in boost::asio::datagram_socket_service::datagram_socket_service at datagram_socket_service.hpp:95 #25 0x0001c59e in boost::asio::detail::service_registry::use_service at service_registry.hpp:109 #26 0x0001c6eb in boost::asio::use_service at io_service.ipp:195 #27 0x0001c711 in boost::asio::basic_io_object ::basic_io_object at basic_io_object.hpp:72 #28 0x0001c783 in boost::asio::basic_socket ::basic_socket at basic_socket.hpp:108 #29 0x0001c865 in boost::asio::basic_datagram_socket ::basic_datagram_socket at basic_datagram_socket.hpp:107 #30 0x000027bc in main at main.cpp:32 This is the gdb output: (gdb) continue /Developer/SDKs/MacOSX10.5.sdk/usr/include/c++/4.0.0/debug/safe_iterator.h:127: error: attempt to copy-construct an iterator from a singular iterator. Objects involved in the operation: iterator "this" @ 0x0x100420 { type = N11__gnu_debug14_Safe_iteratorIN10__gnu_norm14_List_iteratorISt4pairIiPN5boost4asio6detail16reactor_op_queueIiE7op_baseEEEEN15__gnu_debug_def4listISB_SaISB_EEEEE (mutable iterator); state = singular; } iterator "other" @ 0x0xbfffe8a4 { type = N11__gnu_debug14_Safe_iteratorIN10__gnu_norm14_List_iteratorISt4pairIiPN5boost4asio6detail16reactor_op_queueIiE7op_baseEEEEN15__gnu_debug_def4listISB_SaISB_EEEEE (mutable iterator); state = singular; } Program received signal: “SIGABRT”. (gdb) continue Program received signal: “?”. Does someone has any idea why this example does not work on mac osx? Thank you.

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  • Advanced Django query with subselects and custom JOINS

    - by Bryan Ward
    I have been investigating this number theoretic function (found in the Height model) and I need to query for things based on the prime factorization of the primary key, or id. I have created a model for Factors of the id which maintains all of the prime factors. class Height(models.Model): b = models.IntegerField(null=True, blank=True) c = models.IntegerField(null=True, blank=True) d = models.FloatField(null=True, blank=True) class Factors(models.Model): height = models.ForeignKey(Height, null=True, blank=True) factor = models.IntegerField(null=True, blank=True) degree = models.IntegerField(null=True, blank=True) prime_id = models.IntegerField(null=True, blank=True) For example, if id=24, then the associated entries in the factors table would be height_id=24,factor=2,degree=3,prime_id=0 height_id=24,factor=3,degree=1,prime_id=1 the prime_id keep track of the relative order of the primes. Now let p < q < r < s all be prime numbers and a,b,c,d be positive integers. Then I want to be able to query for all Heights of the form id=(p**a)*(q**b)*(r**c)*(s**d). Now this is simple in the case that all of p,q,r,s,a,b,c,d are known in that I can just run Height.objects.get(id=(p**a)*(q**b)*(r**c)*(s**d)) But I need to be able to query for something like (2**a)*(3**2)*(r**c)*(s**d) where r,s,a,d are unknown and all Heights of such form will be returned. Furthermore, not all of the rows in Height will have exactly four prime factors, so I need to make sure that I am not matching rows of the form id=(p**a)*(q**b)*(r**c)*(s**d)*(t**e)... From what I can tell, the following MySQL query accomplishes this, but I would like to do it through the Django ORM. I also don't know if this MySQL query is the proper way to go about doing things. SELECT h.*,count(f.height_id) AS factorsCount FROM height AS h LEFT JOIN factors AS f ON ( f.height_id = h.id AND f.height_id IN (SELECT height_id FROM factors where prime_id=1 AND factor=2 AND degree=1) AND f.height_id IN (SELECT height_id FROM factors where prime_id=2 AND factor=3 AND degree=2) AND f.height_id IN (SELECT height_id FROM factors where prime_id=3 AND factor=5 AND degree=1) AND f.height_id IN (SELECT height_id FROM factors where prime_id=4 AND factor=7 ANd degree=1) ) GROUP BY h.id HAVING factorsCount=4 ORDER BY h.id; Any ideas or suggestions for things to try?

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  • How to produce precisely-timed tone and silence in C#

    - by Bob Denny
    I have a C# project that plays Morse code for RSS feeds. I write it using Managed DirectX, only to discover that Managed DirectX is old and deprecated. The task I have is to play pure sine wave bursts interspersed with silence periods (the code) which are precisely timed as to their duration. I need to be able to call a function which plays a pure tone for so many milliseconds, then Thread.Sleep() then play another, etc. At its fastest, the tones and spaces can be as short as 40ms. It's working quite well in Managed DirectX. To get the precisely timed tone I create 1 sec. of sine wave into a secondary buffer, then to play a tone of a certain duration I seek forward to within x milliseconds of the end of the buffer then play. I've tried System.Media.SoundPlayer. It's a loser because you have to Play(), Sleep(), then Stop() for arbitrary tone lengths. The result is a tone that is too long, variable by CPU load. It takes an indeterminate amount of time to actually stop the tone. I then embarked on a lengthy attempt to use NAudio 1.3. I ended up with a memory resident stream providing the tone data, and again seeking forward leaving the desired length of tone remaining in the stream, then playing. This worked OK on the DirectSoundOut class for a while (see below) but the WaveOut class quickly dies with an internal assert saying that buffers are still on the queue despite PlayerStopped = true. This is odd since I play to the end then put a wait of the same duration between the end of the tone and the start of the next. You'd think that 80ms after starting Play of a 40 ms tone that it wouldn't have buffers on the queue. DirectSoundOut works well for a while, but its problem is that for every tone burst Play() it spins off a separate thread. Eventually (5 min or so) it just stops working. You can see thread after thread after thread exiting in the Output window while running the project in VS2008 IDE. I don't create new objects during playing, I just Seek() the tone stream then call Play() over and over, so I don't think it's a problem with orphaned buffers/whatever piling up till it's choked. I'm out of patience on this one, so I'm asking in the hopes that someone here has faced a similar requirement and can steer me in a direction with a likely solution. Thanks in advance...

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  • please explain NHibernate HiLo

    - by Ben
    I'm struggling to get my head round how the HiLo generator works in NHibernate. I've read the explanation here which made things a little clearer. My understanding is that each SessionFactory retrieves the high value from the database. This improves performance because we have access to IDs without hitting the database. The explanation from the above link also states: For instance, supposing you have a "high" sequence with a current value of 35, and the "low" number is in the range 0-1023. Then the client can increment the sequence to 36 (for other clients to be able to generate keys while it's using 35) and know that keys 35/0, 35/1, 35/2, 35/3... 35/1023 are all available. How does this work in a web application as don't I only have one SessionFactory and therefore one hi value. Does this mean that in a disconnected application you can end up with duplicate (low) ids in your entity table? In my tests I used these settings: <id name="Id" unsaved-value="0"> <generator class="hilo"/> </id> I ran a test to save 100 objects. The IDs in my table went from 32768 - 32868. The next hi value was incremented to 2. Then I ran my test again and the Ids were in the range 65536 - 65636. First off, why start at 32768 and not 1, and secondly why the jump from 32868 to 65536? Now I know that my surrogate keys shouldn't have any meaning but we do use them in our application. Why can't I just have them increment nicely like a SQL Server identity field would. Finally can someone give me an explanation of how the max_lo parameter works? Is this the maximum number of low values (entity ids in my head) that can be created against the high value? This is one topic in NHibernate that I have struggled to find documentation for. I read the entire NHibernate in action book and it still doesn't go into how this works in any detail. Thanks Ben

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  • How do I serialize an object to xml but not have it be the root element of the xml document

    - by mezoid
    I have the following object: public class MyClass { public int Id { get; set;} public string Name { get; set; } } I'm wanting to serialize this to the following xml string: <MyClass> <Id>1</Id> <Name>My Name</Name> </MyClass> Unfortunately, when I use the XMLSerializer I get a string which looks like: <?xml version="1.0" encoding="utf-8"?> <MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Id>1</Id> <Name>My Name</Name> </MyClass> I'm not wanting MyClass to be the root element the document, rather I'm eventually wanting to add the string with other similar serialized objects which will be within a larger xml document. i.e. Eventually I'll have a xml string which looks like this: <Classes> <MyClass> <Id>1</Id> <Name>My Name</Name> </MyClass> <MyClass> <Id>1</Id> <Name>My Name</Name> </MyClass> </Classes>" My first thought was to create a class as follows: public class Classes { public List<MyClass> MyClasses { get; set; } } ...but that just addes an additional node called MyClasses to wrap the list of MyClass.... My gut feeling is that I'm approaching this the wrong way and that my lack of experience with creating xml files isn't helping to point me to some part of the .NET framework or some other library that simplifies this.

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  • NSCollectionView draws nothing

    - by PCWiz
    I'm trying to set up an NSCollectionView (I have done this successfully in the past, but for some reason it fails this time). I have a model class called "TestModel", and it has an NSString property that just returns a string (just for testing purposes right now). I then have an NSMutableArray property declaration in my main app delegate class, and to this array I add instances of the TestModel object. I then have an Array Controller that has its Content Array bound the app delegate's NSMutableArray. I can confirm that everything up to here is working fine; NSLogging: [[[arrayController arrangedObjects] objectAtIndex:0] teststring] worked fine. I then have all the appropriate bindings for the collection view set up, (itemPrototype and content), and for the Collection View Item (view). I then have a text field in the collection item view that is bound to Collection View Item.representedObject.teststring. However NOTHING displays in the collection view when I start the app, just a blank white screen. What am I missing? UPDATE: Here is the code I use (requested by wil shipley): // App delegate class @interface AppController : NSObject { NSMutableArray *objectArray; } @property (readwrite, retain) NSMutableArray *objectArray; @end @implementation AppController @synthesize objectArray; - (id)init { if (self = [super init]) { objectArray = [[NSMutableArray alloc] init]; } return self; } - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { TestModel *test = [[[TestModel alloc] initWithString:@"somerandomstring"] autorelease]; if (test) [objectArray addObject:test]; } @end // The model class (TestModel) @interface TestModel : NSObject { NSString *teststring; } @property (readwrite, retain) NSString *teststring; - (id)initWithString:(NSString*)customString; @end @implementation TestModel @synthesize teststring; - (id)initWithString:(NSString*)customString { [self setTeststring:customString]; } - (void)dealloc { [teststring release]; } @end And then like I said the content array of the Array Controller is bound to this "objectArray", and the Content of the NSCollectionView is bound to Array Controller.arrangedObjects. I can verify that the Array Controller has the objects in it by NSLogging [arrayController arrangedObjects], and it returns the correct object. Its just that nothing displays in the NSCollectionView. UPDATE 2: If I log [collectionView content] I get nothing: 2009-10-21 08:02:42.385 CollViewTest[743:a0f] ( ) The problem is probably there. UPDATE 3: As requested here is the Xcode project: http://www.mediafire.com/?mjgdzgjjfzw Its a menubar app, so it has no window. When you build and run the app you'll see a menubar item that says "test", this opens the view that contains the NSCollectionView. Thanks

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  • Winform radiobutton data binding

    - by Rajarshi
    I am following the "Presentation Model" design pattern suggested by Martin Fowler for my GUI architecture in a Windows Forms project. "The essence of a Presentation Model is of a fully self-contained class that represents all the data and behavior of the UI window, but without any of the controls used to render that UI on the screen. A view then simply projects the state of the presentation model onto the glass...." - Martin Fowler Read more about this pattern at www.martinfowler.com/eaaDev/PresentationModel.html I am finding the concept very fluid and easy to understand except this one issue of data binding RadioButtons to properties on the Data/Domain object. Suposing I have a Windows Form with 3 radio buttons to depict some "Mode" options as - Auto Manual Import How can I use boolean properties on Data/Domain Objects to DataBind to these buttons? I have tried many ways but to no avail. For example I would like to code like - rbtnAutoMode.DataBindings.Add("Text", myBusinessObject, "IsAutoMode"); rbtnManualMode.DataBindings.Add("Text", myBusinessObject, "IsManualMode"); rbtnImportMode.DataBindings.Add("Text", myBusinessObject, "IsImportMode"); There should be a fourth property like "SelectedMode" on the data/domain object which at the end should depict a single value like "SelectedMode = Auto". I am trying to update this property when any of the "IsAutoMode", "IsManualMode" or "IsImportMode" is changed, e.g. through the property setters. I have INotifyPropertyChanged implemented on my data/domain object so, updating any data/domain object property automatically updates my UI controls, that's not an issue. There is a good example of binding 2 radio buttons here - http://stackoverflow.com/questions/344964/how-do-i-use-databinding-with-windows-forms-radio-buttons but I am missing the link while implementing the same with 3 buttons. I am having very erratic behaviors for the Radio Buttons. I hope I was able to explain reasonably. I am actually in a hurry and could not put a detailed code on post, but any help in this regard is appreciated. There is a simple solution to this issue by exposing a method like - public void SetMode(Modes mode) { this._selectedMode = mode; } which could be called from the "CheckedChanged" event of the Radio Buttons from the UI and would perfectly set the "SelectedMode" on the business object, but I need to stretch the limits to verify whether this can be done by DataBinding.

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  • Is this (Lock-Free) Queue Implementation Thread-Safe?

    - by Hosam Aly
    I am trying to create a lock-free queue implementation in Java, mainly for personal learning. The queue should be a general one, allowing any number of readers and/or writers concurrently. Would you please review it, and suggest any improvements/issues you find? Thank you. import java.util.concurrent.atomic.AtomicReference; public class LockFreeQueue<T> { private static class Node<E> { E value; volatile Node<E> next; Node(E value) { this.value = value; } } private AtomicReference<Node<T>> head, tail; public LockFreeQueue() { // have both head and tail point to a dummy node Node<T> dummyNode = new Node<T>(null); head = new AtomicReference<Node<T>>(dummyNode); tail = new AtomicReference<Node<T>>(dummyNode); } /** * Puts an object at the end of the queue. */ public void putObject(T value) { Node<T> newNode = new Node<T>(value); Node<T> prevTailNode = tail.getAndSet(newNode); prevTailNode.next = newNode; } /** * Gets an object from the beginning of the queue. The object is removed * from the queue. If there are no objects in the queue, returns null. */ public T getObject() { Node<T> headNode, valueNode; // move head node to the next node using atomic semantics // as long as next node is not null do { headNode = head.get(); valueNode = headNode.next; // try until the whole loop executes pseudo-atomically // (i.e. unaffected by modifications done by other threads) } while (valueNode != null && !head.compareAndSet(headNode, valueNode)); T value = (valueNode != null ? valueNode.value : null); // release the value pointed to by head, keeping the head node dummy if (valueNode != null) valueNode.value = null; return value; }

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