Search Results

Search found 3956 results on 159 pages for 'constructor overloading'.

Page 141/159 | < Previous Page | 137 138 139 140 141 142 143 144 145 146 147 148  | Next Page >

• how to organise my abstraction?

  - by DaveM

  I have a problem that I can't decide how to best handle, so I'm asking for advice. Please bear with me if my question isn't clear, it is possiblybecause I'm not sure exacly how to solve! I have a set of function that I have in a class. These function are a set of lowest commonality. To be able to run this I need to generate certain info. But this info can arrive with my class from one of 2 routes. I'll try to summarise my situation.... Lets say that I have a class as follows. public class onHoliday(){ private Object modeOfTravel; private Object location; public onHoliday(Object vehicle, Location GPScoords) { private boolean haveFun(){//function to have fun, needs 4 people }//end haveFun() } } Lets imagine I can get to my holiday either by car or by bike. my haveFun() function is dependant my type of vehicle. But only loosely. I have another function that determines my vehicle type, and extracts the required values. for example if I send a car I may get 4 people in one go, but if I send I bike I need at least 2 to get the required 4 I have currently 2 options: Overload my constructor, so as I can send either 2 bikes or a single car into it, then I can call one of 2 intermediate functions (to get the names of my 4 people for instance) before I haveFun() - this is what I am currently doing. split the 2 constructors into 2 separate classes, and repeat my haveFun() in a third class, that becomes an object of my 2 other classes. my problem with this is that my intermediate functions are all but a few lines of code, and I don't want to have them in a separate file! (I allways put classes in separate files!) Please note, my haveFun() isn't something that I'm going to need outside of these 2 classes, or even being onHoliday (ie. there is no chance of me doing some haveFun() over a weekend or of an evening!). I have though about putting haveFun() into an interface, but it seems a bit worthless having an interface with only a single method! Even then I would have to have the method in both of the classes -one for bike and another for car! I have thought about having my onHoliday class accepting any object type, but then I don't want someone accidentally sending in a boat to my onHoliday class (imagine I can't swim, so its not about to happen). It may be important to note that my onHoliday class is package private, and final. It in fact is only accessed via other 'private methods' in other classes, and has only private methods itself. Thanks in advance. David

  Read the article

• detect face from image and crop face from that photo

  - by Siddhpura Amit

  I have done coding in that i am successfully getting face with rectangle drawing now i want to crop that rectangle area. if there are many rectangle( mean many faces) than user can select one of the face or rectangle and that rectangle areal should be cropped can any body help me... Below is my code class AndroidFaceDetector extends Activity { public String path; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle bundle = this.getIntent().getExtras(); path = bundle.getString("mypath"); setContentView(new myView(this)); } class myView extends View { private int imageWidth, imageHeight; private int numberOfFace = 5; private FaceDetector myFaceDetect; private FaceDetector.Face[] myFace; float myEyesDistance; int numberOfFaceDetected; Bitmap myBitmap; public myView(Context context) { super(context); System.out.println("CONSTRUCTOR"); System.out.println("path = "+path); if (path != null) { BitmapFactory.Options BitmapFactoryOptionsbfo = new BitmapFactory.Options(); BitmapFactoryOptionsbfo.inPreferredConfig = Bitmap.Config.RGB_565; myBitmap = BitmapFactory.decodeFile(path, BitmapFactoryOptionsbfo); imageWidth = myBitmap.getWidth(); imageHeight = myBitmap.getHeight(); myFace = new FaceDetector.Face[numberOfFace]; myFaceDetect = new FaceDetector(imageWidth, imageHeight, numberOfFace); numberOfFaceDetected = myFaceDetect.findFaces(myBitmap, myFace); } else { Toast.makeText(AndroidFaceDetector.this, "Please Try again", Toast.LENGTH_SHORT).show(); } } @Override protected void onDraw(Canvas canvas) { System.out.println("ON DRAW IS CALLED"); if (myBitmap != null) { canvas.drawBitmap(myBitmap, 0, 0, null); Paint myPaint = new Paint(); myPaint.setColor(Color.GREEN); myPaint.setStyle(Paint.Style.STROKE); myPaint.setStrokeWidth(3); for (int i = 0; i < numberOfFaceDetected; i++) { Face face = myFace[i]; PointF myMidPoint = new PointF(); face.getMidPoint(myMidPoint); myEyesDistance = face.eyesDistance(); canvas.drawRect((int) (myMidPoint.x - myEyesDistance), (int) (myMidPoint.y - myEyesDistance), (int) (myMidPoint.x + myEyesDistance), (int) (myMidPoint.y + myEyesDistance), myPaint); } } } } }

  Read the article

• Haskell: Left-biased/short-circuiting function

  - by user2967411

  Two classes ago, our professor presented to us a Parser module. Here is the code: module Parser (Parser,parser,runParser,satisfy,char,string,many,many1,(+++)) where import Data.Char import Control.Monad import Control.Monad.State type Parser = StateT String [] runParser :: Parser a -> String -> [(a,String)] runParser = runStateT parser :: (String -> [(a,String)]) -> Parser a parser = StateT satisfy :: (Char -> Bool) -> Parser Char satisfy f = parser $ \s -> case s of [] -> [] a:as -> [(a,as) | f a] char :: Char -> Parser Char char = satisfy . (==) alpha,digit :: Parser Char alpha = satisfy isAlpha digit = satisfy isDigit string :: String -> Parser String string = mapM char infixr 5 +++ (+++) :: Parser a -> Parser a -> Parser a (+++) = mplus many, many1 :: Parser a -> Parser [a] many p = return [] +++ many1 p many1 p = liftM2 (:) p (many p) Today he gave us an assignment to introduce "a left-biased, or short-circuiting version of (+++)", called (<++). His hint was for us to consider the original implementation of (+++). When he first introduced +++ to us, this was the code he wrote, which I am going to call the original implementation: infixr 5 +++ (+++) :: Parser a -> Parser a -> Parser a p +++ q = Parser $ \s -> runParser p s ++ runParser q s I have been having tons of trouble since we were introduced to parsing and so it continues. I have tried/am considering two approaches. 1) Use the "original" implementation, as in p +++ q = Parser $ \s - runParser p s ++ runParser q s 2) Use the final implementation, as in (+++) = mplus Here are my questions: 1) The module will not compile if I use the original implementation. The error: Not in scope: data constructor 'Parser'. It compiles fine using (+++) = mplus. What is wrong with using the original implementation that is avoided by using the final implementation? 2) How do I check if the first Parser returns anything? Is something like (not (isNothing (Parser $ \s - runParser p s) on the right track? It seems like it should be easy but I have no idea. 3) Once I figure out how to check if the first Parser returns anything, if I am to base my code on the final implementation, would it be as easy as this?: -- if p returns something then p <++ q = mplus (Parser $ \s -> runParser p s) mzero -- else (<++) = mplus Best, Jeff

  Read the article

• Help organising controllers logically

  - by kenny99

  Hi guys, I'm working on a site which i'm developing using an MVC structure. My models will represent all of data in the site, but i'm struggling a bit to decide on a good controller structure. The site will allow users to login/register and see personal data on a number of pages, but also still have access to public pages, e.g FAQs, Contact page etc. This is what I have at the moment... A Template Controller which handles main template display. The basic template for the site will remain the same whether or not you are logged in. A main Website Controller which extends the Template Controller and handles basic authentication. If the user is logged in, a User::control_panel() method is called from the constructor and this builds the control panel which will be present throughout the authenticated session. If user is not logged in, then a different view is loaded instead of the control panel, e.g with a login form. All protected/public page related controllers will extend the website controller. The user homepage has a number of widgets I want to display, which I'm doing via a Home Controller which extends the Website Controller. This controller generates these widgets via the following static calls: $this->template->content->featured_pet = Pet::featured(); $this->template->content->popular_names = Pet::most_popular(); $this->template->content->owner_map = User::generate_map(); $this->template->content->news = News::snippet(); I suppose the first thing I'm unsure about is if the above static calls to controllers (e.g Pet and User) are ok to remain static - these static methods will return views which are loaded into the main template. This is the way I've done things in the past but I'm curious to find out if this is a sensible approach. Other protected pages for signed in users will be similar to the Home Controller. Static pages will be handled by a Page Controller which will also extend the Website Controller, so that it will know whether or not the user control panel or login form should be shown on the left hand side of the template. The protected member only pages will not be routed to the Page Controller, this controller will only handle publicly available pages. One problem I have at the moment, is that if both public and protected pages extend the Website Controller, how do I avoid an infinite loop - for example, the idea is that the website controller should handle authentication then redirect to the requested controller (URL), but this will cause an infinite redirect loop, so i need to come up with a better way of dealing with this. All in all, does this setup make any sense?! Grateful for any feedback.

  Read the article

• android - using resources drawable in content provider

  - by Russ Wheeler

  I am trying to pass back an image through a content provider in a separate app. I have two apps, one with the activity in (app a), the other with content provider (app b) I have app a reading an image off my SD card via app b using the following code. App a: public void but_update(View view) { ContentResolver resolver = getContentResolver(); Uri uri = Uri.parse("content://com.jash.cp_source_two.provider/note/1"); InputStream inStream = null; try { inStream = resolver.openInputStream(uri); Bitmap bitmap = BitmapFactory.decodeStream(inStream); image = (ImageView) findViewById(R.id.imageView1); image.setImageBitmap(bitmap); } catch(FileNotFoundException e) { Toast.makeText(getBaseContext(), "error = "+e, Toast.LENGTH_LONG).show(); } finally { if (inStream != null) { try { inStream.close(); } catch (IOException e) { Log.e("test", "could not close stream", e); } } } }; App b: @Override public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException { try { File path = new File(Environment.getExternalStorageDirectory().getAbsolutePath(),"pic2.png"); return ParcelFileDescriptor.open(path,ParcelFileDescriptor.MODE_READ_ONLY); } catch (FileNotFoundException e) { Log.i("r", "File not found"); throw new FileNotFoundException(); } } In app a I am able to display an image from app a's resources folder, using setImageURi and constructing a URI using the following code. int id = R.drawable.a2; Resources resources = getBaseContext().getResources(); Uri uri = Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + resources.getResourcePackageName(id) + '/' + resources.getResourceTypeName(id) + '/' + resources.getResourceEntryName(id) ); image = (ImageView) findViewById(R.id.imageView1); image.setImageURI(uri); However, if I try to do the same in app b (read from app b's resources folder rather than the image on the SD card) it doesn't work, saying it can't find the file, even though I am creating the path of the file from the resource, so it is definitely there. Any ideas? Does it restrict sending resources over the content provider somehow? P.S. I also got an error when I tried to create the file with File path = new File(uri); saying 'there is no applicable constructor to '(android.net.Uri)' though http://developer.android.com/reference/java/io/File.html#File(java.net.URI) Seems to think it's possible...unless java.net.URI is different to android.net.URI, in which case can I convert them? Thanks Russ

  Read the article

• MVVM: how to set the datacontext of a user control

  - by EVA

  Hi, I'm writing an application in WPF, using the MVVm toolkit and have problems with hooking up the viewmodel and view. The model is created with ado.net entity framework. The viewmodel: public class CustomerViewModel { private Models.Customer customer; //constructor private ObservableCollection<Models.Customer> _customer = new ObservableCollection<Models.Customer>(); public ObservableCollection<Models.Customer> AllCustomers { get { return _customer; } } private Models.Customer _selectedItem; public Models.Customer SelectedItem { get { return _selectedItem; } } public void LoadCustomers() { List<Models.Customer> list = DataAccessLayer.getcustomers(); foreach (Models.Customer customer in list) { this._customer.Add(customer); } } } And the view (no code behind at the moment): <UserControl x:Class="Customers.Customer" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d" xmlns:vm ="clr-namespace:Customers.ViewModels" d:DesignHeight="300" d:DesignWidth="300" xmlns:toolkit="http://schemas.microsoft.com/wpf/2008/toolkit" > <Grid> <toolkit:DataGrid ItemsSource="{Binding AllCustomers}" SelectedItem="{Binding SelectedItem, Mode=TwoWay}" AutoGenerateColumns="True"> </toolkit:DataGrid> <toolkit:DataGrid ItemsSource="{Binding SelectedItem.Orders}"> </toolkit:DataGrid> </Grid> </UserControl> And dataaccesslayer class: class DataAccessLayer { public List<Customer> customers = new List<Customer>(); public static List<Customer> getcustomers() { entities db = new entities(); var customers = from c in db.Customer.Include("Orders") select c; return customers.ToList(); } } The problem is that no data is displayed simply because the data context is not set. I tried to do it in a code-behind but is did not work. I would prefer to do it in a xaml file anyway. Another problem is with the SelectedItem binding - the code is never used. Thanks for help! Regards, EV.

  Read the article

• Handwritten linked list is segfaulting and I don't understand why

  - by Born2Smile

  Hi I was working on a bit of fun, making an interface to run gnuplot from within c++, and for some reason the my linked list implementation fails. The code below fails on the line plots-append(&plot). Stepping through the code I discovered that for some reason the destructor ~John() is called immediately after the constructor John(), and I cannot seem to figure out why. The code included below is a stripped down version operating only on Plot*. Originally I made the linked list as a template class. And it worked fine as ll<int and ll<char* but for some reason it fails as ll<Plot*. Could youp please help me figure out why it fails? and perhaps help me understand how to make it work? In advance: Thanks a heap! //B2S #include <string.h class Plot{ char title[80]; public: Plot(){ } }; class Link{ Plot* element; Link* next; Link* prev; friend class ll; }; class ll{ Link* head; Link* tail; public: ll(){ head = tail = new Link(); head-prev = tail-prev = head-next = tail-next = head; } ~ll(){ while (head!=tail){ tail = tail-prev; delete tail-next; } delete head; } void append(Plot* element){ tail-element = element; tail-next = new Link(); tail-next-prev = tail; tail-next = tail; } }; class John{ ll* plots; public: John(){ plots= new ll(); } ~John(){ delete plots; } John(Plot* plot){ John(); plots-append(plot); } }; int main(){ Plot p; John k(&p); }

  Read the article

• Java Threading Concept Understanding

  - by Nirmal

  Hello All... Recently I have gone through with one simple threading program, which leads me some issues for the related concepts... My sample program code looks like : class NewThread implements Runnable { Thread t; NewThread() { t = new Thread(this, "Demo Thread"); System.out.println("Child thread: " + t); t.start(); // Start the thread } public void run() { try { for (int i = 5; i > 0; i--) { System.out.println("Child Thread: " + i); Thread.sleep(500); } } catch (InterruptedException e) { System.out.println("Child interrupted."); } System.out.println("Exiting child thread."); } } class ThreadDemo { public static void main(String args[]) { new NewThread(); // create a new thread try { for (int i = 5; i > 0; i--) { System.out.println("Main Thread: " + i); Thread.sleep(1000); } } catch (InterruptedException e) { System.out.println("Main thread interrupted."); } System.out.println("Main thread exiting."); } } Now this program giving me the output as follows : Child thread: Thread[Demo Thread,5,main] Main Thread: 5 Child Thread: 5 Child Thread: 4 Main Thread: 4 Child Thread: 3 Child Thread: 2 Main Thread: 3 Child Thread: 1 Exiting child thread. Main Thread: 2 Main Thread: 1 Main thread exiting. So, that's very much clear to me. But as soon as I am replacing the object creation code (calling of a NewThread class constructor) to as follows : NewThread nt = new NewThread(); // create a new thread the output becomes a bit varied like as follows : Child thread: Thread[Demo Thread,5,main] Main Thread: 5 Child Thread: 5 Child Thread: 4 Child Thread: 3 Main Thread: 4 Child Thread: 2 Child Thread: 1 Main Thread: 3 Exiting child thread. Main Thread: 2 Main Thread: 1 Main thread exiting. And some times it's giving me same output in both the cases. So, i am not getting the exact change in both the scenario. I would like to know that you the variation in the output is coming here ? Thanks in advance...

  Read the article

• Mixing policy-based design with CRTP in C++

  - by Eitan

  I'm attempting to write a policy-based host class (i.e., a class that inherits from its template class), with a twist, where the policy class is also templated by the host class, so that it can access its types. One example where this might be useful is where a policy (used like a mixin, really), augments the host class with a polymorphic clone() method. Here's a minimal example of what I'm trying to do: template <template <class> class P> struct Host : public P<Host<P> > { typedef P<Host<P> > Base; typedef Host* HostPtr; Host(const Base& p) : Base(p) {} }; template <class H> struct Policy { typedef typename H::HostPtr Hptr; Hptr clone() const { return Hptr(new H((Hptr)this)); } }; Policy<Host<Policy> > p; Host<Policy> h(p); int main() { return 0; } This, unfortunately, fails to compile, in what seems to me like circular type dependency: try.cpp: In instantiation of ‘Host<Policy>’: try.cpp:10: instantiated from ‘Policy<Host<Policy> >’ try.cpp:16: instantiated from here try.cpp:2: error: invalid use of incomplete type ‘struct Policy<Host<Policy> >’ try.cpp:9: error: declaration of ‘struct Policy<Host<Policy> >’ try.cpp: In constructor ‘Host<P>::Host(const P<Host<P> >&) [with P = Policy]’: try.cpp:17: instantiated from here try.cpp:5: error: type ‘Policy<Host<Policy> >’ is not a direct base of ‘Host<Policy>’ If anyone can spot an obvious mistake, or has successfuly mixing CRTP in policies, I would appreciate any help.

  Read the article

• Mouse wheel not scrolling in JDialog

  - by Iulian Serbanoiu

  Hello, I'm facing a frustrating issue. I have an application where the scroll wheel doesn't work in a JDialog class. Here's the code: import javax.swing.*; import java.awt.event.*; public class Failtest extends JFrame { public static void main(String[] args) { new Failtest(); } public Failtest() { super(); setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); setTitle("FRAME"); JScrollPane sp1 = new JScrollPane(getNewList()); add(sp1); setSize(150, 150); setVisible(true); JDialog d = new JDialog(this, false);// NOT WORKING //JDialog d = new JDialog((JFrame)null, false); // NOT WORKING //JDialog d = new JDialog((JDialog)null, false);// WORKING - WHY? d.setTitle("DIALOG"); d.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE); JScrollPane sp = new JScrollPane(getNewList()); d.add(sp); d.setSize(150, 150); d.setVisible(true); } public JList getNewList() { String objs[] = new String[30]; for(int i=0; i<objs.length; i++) { objs[i] = "Item "+i; } JList l = new JList(objs); return l; } } I found a solution which is present as a comment in the java code - the constructor receiving a (JDialog)null parameter. Can someone enlighten me? My opinion is that this is a java bug. Tested on Windows XP-SP3 with 1 JDK and 2 JREs: D:\Program Files\Java\jdk1.6.0_17\bin>javac -version javac 1.6.0_17 D:\Program Files\Java\jdk1.6.0_17\bin>java -version java version "1.6.0_17" Java(TM) SE Runtime Environment (build 1.6.0_17-b04) Java HotSpot(TM) Client VM (build 14.3-b01, mixed mode, sharing) D:\Program Files\Java\jdk1.6.0_17\bin>cd .. D:\Program Files\Java\jdk1.6.0_17>java -version java version "1.6.0_18" Java(TM) SE Runtime Environment (build 1.6.0_18-b07) Java HotSpot(TM) Client VM (build 16.0-b13, mixed mode, sharing) Thank you in advance, Iulian Serbanoiu PS: The problem is not new - the code is taken from a forum (here) where this problem was also mentioned - but no solutions to it (yet)

  Read the article

• using Java interfaces

  - by mike_hornbeck

  I need to create interface MultiLingual, that allows to display object's data in different languages (not data itself, but introduction like "Author", "Title" etc.). Printed data looks like this : 3 grudnia 1998 10th of June 1924 Autor: Tolkien Tytul: LoTR Wydawnictwo: Amazon 2010 Author: Mitch Albom Title: Tuesdays with Morrie Publishing House: Time Warner Books 2003 37 360,45 PLN 5,850.70 GBP 3rd of December 1998 10th of June 1924 Author: Tolkien Title: LoTR Publishing House: Amazon 2010 Author: Mitch Albom Title: Tuesdays with Morrie Publishing House: Time Warner Books 2003 37,360.45 GBP 5,850.70 GBP Test code looks like this : public class Main { public static void main(String[] args){ MultiLingual gatecrasher[]={ new Data(3,12,1998), new Data(10,6,1924,MultiLingual.ENG), new Book("LoTR", "Tolkien", "Amazon", 2010), new Book("Tuesdays with Morrie", "Mitch Albom", "Time Warner Books",2003, MultiLingual.ENG), new Money(1232895/33.0,MultiLingual.PL), new Money(134566/23.0,MultiLingual.ENG), }; for(int i=0;i < gatecrasher.length;i++) System.out.println(gatecrasher[i]+"\n"); for(int i=0;i < gatecrasher.length;i++) System.out.println(gatecrasher[i].get(MultiLingual.ENG)+"\n"); } } So i need to introduce constants ENG, PL in MultiLingual interface, as well as method get(int language) : public interface MultiLingual { int ENG = 0; int PL= 1; String get(int lang); } And then I have class Book. Problem starts with the constructors. One of them needs to take MultiLingual.ENG as argument, but how to achieve that ? Is this the proper way? : class Book implements MultiLingual { private String title; private String publisher; private String author; public Book(String t, String a, String p, int y, MultiLingual lang){ } Or should I treat this MultiLingual.ENG as int variable , that will just change automatically constants in interface? Second constructor for book doesn't take MultLingual as argument, but following implementation is somehow wrong : public Book(String t, String a, String p, int y){ Book someBook = new Book(t, a, p, y, MultiLingual m); } I could just send int m in place of MultiLingual m but then I will have no control if language is set to PL or ENG. And finally get() method for Boook but I think at least this should be working fine: public String get(int lang){ String data; if (lang == ENG){ data = "Author: "+this.author+"\n"+ "Title: "+this.title+"\n"+ "Publisher: "+this.publisher+"\n"; } else { data = "Autor: "+this.author+"\n"+ "Tytul: "+this.title+"\n"+ "Wydawca: "+this.publisher+"\n"; } return data; } @Override public String toString(){ return ""; } }

  Read the article

• Catching an exception class within a template

  - by Todd Bauer

  I'm having a problem using the exception class Overflow() for a Stack template I'm creating. If I define the class regularly there is no problem. If I define the class as a template, I cannot make my call to catch() work properly. I have a feeling it's simply syntax, but I can't figure it out for the life of me. #include<iostream> #include<exception> using namespace std; template <class T> class Stack { private: T *stackArray; int size; int top; public: Stack(int size) { this->size = size; stackArray = new T[size]; top = 0; } ~Stack() { delete[] stackArray; } void push(T value) { if (isFull()) throw Overflow(); stackArray[top] = value; top++; } bool isFull() { if (top == size) return true; else return false; } class Overflow {}; }; int main() { try { Stack<double> Stack(5); Stack.push( 5.0); Stack.push(10.1); Stack.push(15.2); Stack.push(20.3); Stack.push(25.4); Stack.push(30.5); } catch (Stack::Overflow) { cout << "ERROR! The stack is full.\n"; } return 0; } The problem is in the catch (Stack::Overflow) statement. As I said, if the class is not a template, this works just fine. However, once I define it as a template, this ceases to work. I've tried all sorts of syntaxes, but I always get one of two sets of error messages from the compiler. If I use catch(Stack::Overflow): ch18pr01.cpp(89) : error C2955: 'Stack' : use of class template requires template argument list ch18pr01.cpp(13) : see declaration of 'Stack' ch18pr01.cpp(89) : error C2955: 'Stack' : use of class template requires template argument list ch18pr01.cpp(13) : see declaration of 'Stack' ch18pr01.cpp(89) : error C2316: 'Stack::Overflow' : cannot be caught as the destructor and/or copy constructor are inaccessible EDIT: I meant If I use catch(Stack<double>::Overflow) or any variety thereof: ch18pr01.cpp(89) : error C2061: syntax error : identifier 'Stack' ch18pr01.cpp(89) : error C2310: catch handlers must specify one type ch18pr01.cpp(95) : error C2317: 'try' block starting on line '75' has no catch handlers I simply can not figure this out. Does anyone have any idea?

  Read the article

• How do you handle EF Data Contexts combined with asp.net custom membership/role providers

  - by KallDrexx

  I can't seem to get my head around how to implement a custom membership provider with Entity Framework data contexts into my asp.net MVC application. I understand how to create a custom membership/role provider by itself (using this as a reference). Here's my current setup: As of now I have a repository factory interface that allows different repository factories to be created (right now I only have a factory for EF repositories and and in memory repositories). The repository factory looks like this: public class EFRepositoryFactory : IRepositoryFactory { private EntitiesContainer _entitiesContext; /// <summary> /// Constructor that generates the necessary object contexts /// </summary> public EFRepositoryFactory() { _entitiesContext = new EntitiesContainer(); } /// <summary> /// Generates a new entity framework repository for the specified entity type /// </summary> /// <typeparam name="T">Type of entity to generate a repository for </typeparam> /// <returns>Returns an EFRepository</returns> public IRepository<T> GenerateRepository<T>() where T : class { return new EFRepository<T>(_entitiesContext); } } Controllers are passed an EF repository factory via castle Windsor. The controller then creates all the service/business layer objects it requires and passes in the repository factory into it. This means that all service objects are using the same EF data contexts and I do not have to worry about objects being used in more than one data context (which of course is not allowed and causes an exception). As of right now I am trying to decide how to generate my user and authorization service layers, and have run against a design roadblock. The User/Authization service will be a central class that handles the logic for logging in, changing user details, managing roles and determining what users have access to what. The problem is, using the current methodology the asp.net mvc controllers will initialize it's own EF repository factory via Windsor and the asp.net membership/role provider will have to initialize it's own EF repository factory. This means that each part of the site will then have it's own data context. This seems to mean that if asp.net authenticates a user, that user's object will be in the membership provider's data context and thus if I try to retrieve that user object in the service layer (say to change the user's name) I will get a duplication exception. I thought of making the repository factory class a singleton, but I don't see a way for that to work with castle Windsor. How do other people handle asp.net custom providers in a MVC (or any n-tier) architecture without having object duplication issues?

  Read the article

• Binding Silverlight UserControl custom properties to its' elements

  - by ghostskunks

  Hi. I'm trying to make a simple crossword puzzle game in Silverlight 2.0. I'm working on a UserControl-ish component that represents a square in the puzzle. I'm having trouble with binding up my UserControl's properties with its' elements. I've finally (sort of) got it working (may be helpful to some - it took me a few long hours), but wanted to make it more 'elegant'. I've imagined it should have a compartment for the content and a label (in the upper right corner) that optionally contains its' number. The content control probably be a TextBox, while label control could be a TextBlock. So I created a UserControl with this basic structure (the values are hardcoded at this stage): <UserControl x:Class="XWord.Square" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" FontSize="30" Width="100" Height="100"> <Grid x:Name="LayoutRoot" Background="White"> <Grid.ColumnDefinitions> <ColumnDefinition Width="*"/> <ColumnDefinition Width="Auto"/> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <TextBlock x:Name="Label" Grid.Row="0" Grid.Column="1" Text="7"/> <TextBox x:Name="Content" Grid.Row="1" Grid.Column="0" Text="A" BorderThickness="0" /> </Grid> </UserControl> I've also created DependencyProperties in the Square class like this: public static readonly DependencyProperty LabelTextProperty; public static readonly DependencyProperty ContentCharacterProperty; // ...(static constructor with property registration, .NET properties // omitted for brevity)... Now I'd like to figure out how to bind the Label and Content element to the two properties. I do it like this (in the code-behind file): Label.SetBinding( TextBlock.TextProperty, new Binding { Source = this, Path = new PropertyPath( "LabelText" ), Mode = BindingMode.OneWay } ); Content.SetBinding( TextBox.TextProperty, new Binding { Source = this, Path = new PropertyPath( "ContentCharacter" ), Mode = BindingMode.TwoWay } ); That would be more elegant done in XAML. Does anyone know how that's done?

  Read the article

• Error in creating template class

  - by Luciano

  I found this vector template class implementation, but it doesn't compile on XCode. Header file: // File: myvector.h #ifndef _myvector_h #define _myvector_h template <typename ElemType> class MyVector { public: MyVector(); ~MyVector(); int size(); void add(ElemType s); ElemType getAt(int index); private: ElemType *arr; int numUsed, numAllocated; void doubleCapacity(); }; #include "myvector.cpp" #endif Implementation file: // File: myvector.cpp #include <iostream> #include "myvector.h" template <typename ElemType> MyVector<ElemType>::MyVector() { arr = new ElemType[2]; numAllocated = 2; numUsed = 0; } template <typename ElemType> MyVector<ElemType>::~MyVector() { delete[] arr; } template <typename ElemType> int MyVector<ElemType>::size() { return numUsed; } template <typename ElemType> ElemType MyVector<ElemType>::getAt(int index) { if (index < 0 || index >= size()) { std::cerr << "Out of Bounds"; abort(); } return arr[index]; } template <typename ElemType> void MyVector<ElemType>::add(ElemType s) { if (numUsed == numAllocated) doubleCapacity(); arr[numUsed++] = s; } template <typename ElemType> void MyVector<ElemType>::doubleCapacity() { ElemType *bigger = new ElemType[numAllocated*2]; for (int i = 0; i < numUsed; i++) bigger[i] = arr[i]; delete[] arr; arr = bigger; numAllocated*= 2; } If I try to compile as is, I get the following error: "Redefinition of 'MyVector::MyVector()'" The same error is displayed for every member function (.cpp file). In order to fix this, I removed the '#include "myvector.h"' on the .cpp file, but now I get a new error: "Expected constructor, destructor, or type conversion before '<' token". A similar error is displayed for every member as well. Interestingly enough, if I move all the .cpp code to the header file, it compiles fine. Does that mean I can't implement template classes in separate files?

  Read the article

• Use native HBitmap in C# while preserving alpha channel/transparency. Please check this code, it works on my computer...

  - by David

  Let's say I get a HBITMAP object/handle from a native Windows function. I can convert it to a managed bitmap using Bitmap.FromHbitmap(nativeHBitmap), but if the native image has transparency information (alpha channel), it is lost by this conversion. There are a few questions on Stack Overflow regarding this issue. Using information from the first answer of this question (How to draw ARGB bitmap using GDI+?), I wrote a piece of code that I've tried and it works. It basically gets the native HBitmap width, height and the pointer to the location of the pixel data using GetObject and the BITMAP structure, and then calls the managed Bitmap constructor: Bitmap managedBitmap = new Bitmap(bitmapStruct.bmWidth, bitmapStruct.bmHeight, bitmapStruct.bmWidth * 4, PixelFormat.Format32bppArgb, bitmapStruct.bmBits); As I understand (please correct me if I'm wrong), this does not copy the actual pixel data from the native HBitmap to the managed bitmap, it simply points the managed bitmap to the pixel data from the native HBitmap. And I don't draw the bitmap here on another Graphics (DC) or on another bitmap, to avoid unnecessary memory copying, especially for large bitmaps. I can simply assign this bitmap to a PictureBox control or the the Form BackgroundImage property. And it works, the bitmap is displayed correctly, using transparency. When I no longer use the bitmap, I make sure the BackgroundImage property is no longer pointing to the bitmap, and I dispose both the managed bitmap and the native HBitmap. The Question: Can you tell me if this reasoning and code seems correct. I hope I will not get some unexpected behaviors or errors. And I hope I'm freeing all the memory and objects correctly. private void Example() { IntPtr nativeHBitmap = IntPtr.Zero; /* Get the native HBitmap object from a Windows function here */ // Create the BITMAP structure and get info from our nativeHBitmap NativeMethods.BITMAP bitmapStruct = new NativeMethods.BITMAP(); NativeMethods.GetObjectBitmap(nativeHBitmap, Marshal.SizeOf(bitmapStruct), ref bitmapStruct); // Create the managed bitmap using the pointer to the pixel data of the native HBitmap Bitmap managedBitmap = new Bitmap( bitmapStruct.bmWidth, bitmapStruct.bmHeight, bitmapStruct.bmWidth * 4, PixelFormat.Format32bppArgb, bitmapStruct.bmBits); // Show the bitmap this.BackgroundImage = managedBitmap; /* Run the program, use the image */ MessageBox.Show("running..."); // When the image is no longer needed, dispose both the managed Bitmap object and the native HBitmap this.BackgroundImage = null; managedBitmap.Dispose(); NativeMethods.DeleteObject(nativeHBitmap); } internal static class NativeMethods { [StructLayout(LayoutKind.Sequential)] public struct BITMAP { public int bmType; public int bmWidth; public int bmHeight; public int bmWidthBytes; public ushort bmPlanes; public ushort bmBitsPixel; public IntPtr bmBits; } [DllImport("gdi32", CharSet = CharSet.Auto, EntryPoint = "GetObject")] public static extern int GetObjectBitmap(IntPtr hObject, int nCount, ref BITMAP lpObject); [DllImport("gdi32.dll")] internal static extern bool DeleteObject(IntPtr hObject); }

  Read the article

• redoing object model construction to fit with asynchronous data fetching

  - by Andrew Patterson

  I have a modeled a set of objects that correspond with some real world concepts. TradeDrug, GenericDrug, TradePackage, DrugForm Underlying the simple object model I am trying to provide is a complex medical terminology that uses numeric codes to represent relationships and concepts, all accessible via a REST service - I am trying to hide away some of that complexity with an object wrapper. To give a concrete example I can call TradeDrug d = Searcher.FindTradeDrug("Zoloft") or TradeDrug d = new TradeDrug(34) where 34 might be the code for Zoloft. This will consult a remote server to find out some details about Zoloft. I might then call GenericDrug generic = d.EquivalentGeneric() System.Out.WriteLine(generic.ActiveIngredient().Name) in order to get back the generic drug sertraline as an object (again via a background REST call to the remote server that has all these drug details), and then perhaps find its ingredient. This model works fine and is being used in some applications that involve data processing. Recently however I wanted to do a silverlight application that used and displayed these objects. The silverlight environment only allows asynchronous REST/web service calls. I have no problems with how to make the asychhronous calls - but I am having trouble with what the design should be for my object construction. Currently the constructors for my objects do some REST calls sychronously. public TradeDrug(int code) { form = restclient.FetchForm(code) name = restclient.FetchName(code) etc.. } If I have to use async 'events' or 'actions' in order to use the Silverlight web client (I know silverlight can be forced to be a synchronous client but I am interested in asychronous approaches), does anyone have an guidance or best practice for how to structure my objects. I can pass in an action callback to the constructor public TradeDrug(int code, Action<TradeDrug> constructCompleted) { } but this then allows the user to have a TradeDrug object instance before what I want to construct is actually finished. It also doesn't support an 'event' async pattern because the object doesn't exist to add the event to until it is constructed. Extending that approach might be a factory object that itself has an asynchronous interface to objects factory.GetTradeDrugAsync(code, completedaction) or with a GetTradeDrugCompleted event? Does anyone have any recommendations?

  Read the article

• Unique ID Defined by Most-Derived Class accessible through Base Class

  - by Narfanator

  Okay, so, the idea is that I have a map of "components", which inherit from componentBase, and are keyed on an ID unique to the most-derived*. Only, I can't think of a good way to get this to work. I tried it with the constructor, but that doesn't work (Maybe I did it wrong). The problem with any virtual, etc, inheritance tricks are that the user has to impliment them at the bottom, which can be forgotten and makes it less... clean. *Right phrase? If - is inheritance; foo is most-derived: foo-foo1-foo2-componentBase Here's some code showing the problem, and why CRTP can't cut it: (No, it's not legit code, but I'm trying to get my thoughts down) #include<map> class componentBase { public: virtual static char idFunction() = 0; }; template <class T> class component : public virtual componentBase { public: static char idFunction(){ return reinterpret_cast<char>(&idFunction); } }; class intermediateDerivations1 : public virtual component<intermediateDerivations1> { }; class intermediateDerivations2 : public virtual component<intermediateDerivations2> { }; class derived1 : public intermediateDerivations1 { }; class derived2 : public intermediateDerivations1 { }; //How the unique ID gets used (more or less) std::map<char, componentBase*> TheMap; template<class T> void addToMap(componentBase * c) { TheMap[T::idFunction()] = c; } template<class T> T * getFromMap() { return TheMap[T::idFunction()]; } int main() { //In each case, the key needs to be different. //For these, the CRTP should do it: getFromMap<intermediateDerivations1>(); getFromMap<intermediateDerivations2>(); //But not for these. getFromMap<derived1>(); getFromMap<derived2>(); return 0; } More or less, I need something that is always there, no matter what the user does, and has a sortable value that's unique to the most-derived class. Also, I realize this isn't the best-asked question, I'm actually having some unexpected difficultly wrapping my head around it in words, so ask questions if/when you need clarification.

  Read the article

• Why am I seeing a crash when trying to call CDHtmlDialog::OnInitDialog()

  - by Tim

  I added a helpAbout menu item to my mfc app. I decided to make the ddlg derive from CDHTMLDialog. I override the OnInitDialog() method in my derived class and the first thing I do is call the parent's OnInitDialog() method. I then put in code that sets the title. On some machines this works fine, but on others it crashes in the call to CDHtmlDialog::OnInitDialog() - Trying to read a null pointer. the call stack has nothing useful - it is in mfc90.dll Is this a potential problem with mismatches of mfc/win32 dlls? It works on my vista machines but crashes on a win2003 server box. BOOL HTMLAboutDlg::OnInitDialog() { // CRASHES on the following line CDHtmlDialog::OnInitDialog(); CString title = "my title"; // example of setting title // i try to get version info //set the title CModuleVersion ver; char filename[ _MAX_PATH ]; GetModuleFileName( AfxGetApp()->m_hInstance, filename, _MAX_PATH ); ver.GetFileVersionInfo(filename); // get version from VS_FIXEDFILEINFO struct CString s; s.Format("Version: %d.%d.%d.%d\n", HIWORD(ver.dwFileVersionMS), LOWORD(ver.dwFileVersionMS), HIWORD(ver.dwFileVersionLS), LOWORD(ver.dwFileVersionLS)); CString version = ver.GetValue(_T("ProductVersion")); version.Remove(' '); version.Replace(",", "."); title = "MyApp - Version " + version; SetWindowText(title); return TRUE; // return TRUE unless you set the focus to a control } And here is the relevant header file: class HTMLAboutDlg : public CDHtmlDialog { DECLARE_DYNCREATE(HTMLAboutDlg) public: HTMLAboutDlg(CWnd* pParent = NULL); // standard constructor virtual ~HTMLAboutDlg(); // Overrides HRESULT OnButtonOK(IHTMLElement *pElement); HRESULT OnButtonCancel(IHTMLElement *pElement); // Dialog Data enum { IDD = IDD_DIALOG_ABOUT, IDH = IDR_HTML_HTMLABOUTDLG }; protected: virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support virtual BOOL OnInitDialog(); DECLARE_MESSAGE_MAP() DECLARE_DHTML_EVENT_MAP() }; I can't figure out what is going on - why it works on some machins and crashes on others. Both have VS2008 installed EDIT: VS versions VISTA - no crashes 9.0.30729.1 SP 2003 server: (crashes) 9.0.21022.8 RTM

  Read the article

• Blackberry Player, custom data source

  - by Alex

  Hello I must create a custom media player within the application with support for mp3 and wav files. I read in the documentation i cant seek or get the media file duration without a custom datasoruce. I checked the demo in the JDE 4.6 but i have still problems... I cant get the duration, it return much more then the expected so i`m sure i screwed up something while i modified the code to read the mp3 file locally from the filesystem. Somebody can help me what i did wrong ? (I can hear the mp3, so the player plays it correctly from start to end) I must support OSs = 4.6. Thank You Here is my modified datasource LimitedRateStreaminSource.java * Copyright © 1998-2009 Research In Motion Ltd. Note: For the sake of simplicity, this sample application may not leverage resource bundles and resource strings. However, it is STRONGLY recommended that application developers make use of the localization features available within the BlackBerry development platform to ensure a seamless application experience across a variety of languages and geographies. For more information on localizing your application, please refer to the BlackBerry Java Development Environment Development Guide associated with this release. */ package com.halcyon.tawkwidget.model; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import javax.microedition.io.Connector; import javax.microedition.io.file.FileConnection; import javax.microedition.media.Control; import javax.microedition.media.protocol.ContentDescriptor; import javax.microedition.media.protocol.DataSource; import javax.microedition.media.protocol.SourceStream; import net.rim.device.api.io.SharedInputStream; /** * The data source used by the BufferedPlayback's media player. / public final class LimitedRateStreamingSource extends DataSource { /* The max size to be read from the stream at one time. */ private static final int READ_CHUNK = 512; // bytes /** A reference to the field which displays the load status. */ //private TextField _loadStatusField; /** A reference to the field which displays the player status. */ //private TextField _playStatusField; /** * The minimum number of bytes that must be buffered before the media file * will begin playing. */ private int _startBuffer = 200000; /** The maximum size (in bytes) of a single read. */ private int _readLimit = 32000; /** * The minimum forward byte buffer which must be maintained in order for * the video to keep playing. If the forward buffer falls below this * number, the playback will pause until the buffer increases. */ private int _pauseBytes = 64000; /** * The minimum forward byte buffer required to resume * playback after a pause. */ private int _resumeBytes = 128000; /** The stream connection over which media content is passed. */ //private ContentConnection _contentConnection; private FileConnection _fileConnection; /** An input stream shared between several readers. */ private SharedInputStream _readAhead; /** A stream to the buffered resource. */ private LimitedRateSourceStream _feedToPlayer; /** The MIME type of the remote media file. */ private String _forcedContentType; /** A counter for the total number of buffered bytes */ private volatile int _totalRead; /** A flag used to tell the connection thread to stop */ private volatile boolean _stop; /** * A flag used to indicate that the initial buffering is complete. In * other words, that the current buffer is larger than the defined start * buffer size. */ private volatile boolean _bufferingComplete; /** A flag used to indicate that the remote file download is complete. */ private volatile boolean _downloadComplete; /** The thread which retrieves the remote media file. */ private ConnectionThread _loaderThread; /** The local save file into which the remote file is written. */ private FileConnection _saveFile; /** A stream for the local save file. */ private OutputStream _saveStream; /** * Constructor. * @param locator The locator that describes the DataSource. */ public LimitedRateStreamingSource(String locator) { super(locator); } /** * Open a connection to the locator. * @throws IOException */ public void connect() throws IOException { //Open the connection to the remote file. _fileConnection = (FileConnection)Connector.open(getLocator(), Connector.READ); //Cache a reference to the locator. String locator = getLocator(); //Report status. System.out.println("Loading: " + locator); //System.out.println("Size: " + _contentConnection.getLength()); System.out.println("Size: " + _fileConnection.totalSize()); //The name of the remote file begins after the last forward slash. int filenameStart = locator.lastIndexOf('/'); //The file name ends at the first instance of a semicolon. int paramStart = locator.indexOf(';'); //If there is no semicolon, the file name ends at the end of the line. if (paramStart < 0) { paramStart = locator.length(); } //Extract the file name. String filename = locator.substring(filenameStart, paramStart); System.out.println("Filename: " + filename); //Open a local save file with the same name as the remote file. _saveFile = (FileConnection) Connector.open("file:///SDCard/blackberry/music" + filename, Connector.READ_WRITE); //If the file doesn't already exist, create it. if (!_saveFile.exists()) { _saveFile.create(); } System.out.println("---------- 1"); //Open the file for writing. _saveFile.setReadable(true); //Open a shared input stream to the local save file to //allow many simultaneous readers. SharedInputStream fileStream = SharedInputStream.getSharedInputStream(_saveFile.openInputStream()); //Begin reading at the beginning of the file. fileStream.setCurrentPosition(0); System.out.println("---------- 2"); //If the local file is smaller than the remote file... if (_saveFile.fileSize() < _fileConnection.totalSize()) { System.out.println("---------- 3"); //Did not get the entire file, set the system to try again. _saveFile.setWritable(true); System.out.println("---------- 4"); //A non-null save stream is used as a flag later to indicate that //the file download was incomplete. _saveStream = _saveFile.openOutputStream(); System.out.println("---------- 5"); //Use a new shared input stream for buffered reading. _readAhead = SharedInputStream.getSharedInputStream(_fileConnection.openInputStream()); System.out.println("---------- 6"); } else { //The download is complete. System.out.println("---------- 7"); _downloadComplete = true; //We can use the initial input stream to read the buffered media. _readAhead = fileStream; System.out.println("---------- 8"); //We can close the remote connection. _fileConnection.close(); System.out.println("---------- 9"); } if (_forcedContentType != null) { //Use the user-defined content type if it is set. System.out.println("---------- 10"); _feedToPlayer = new LimitedRateSourceStream(_readAhead, _forcedContentType); System.out.println("---------- 11"); } else { System.out.println("---------- 12"); //Otherwise, use the MIME types of the remote file. // _feedToPlayer = new LimitedRateSourceStream(_readAhead, _fileConnection)); } System.out.println("---------- 13"); } /** * Destroy and close all existing connections. */ public void disconnect() { try { if (_saveStream != null) { //Destroy the stream to the local save file. _saveStream.close(); _saveStream = null; } //Close the local save file. _saveFile.close(); if (_readAhead != null) { //Close the reader stream. _readAhead.close(); _readAhead = null; } //Close the remote file connection. _fileConnection.close(); //Close the stream to the player. _feedToPlayer.close(); } catch (Exception e) { System.err.println(e.getMessage()); } } /** * Returns the content type of the remote file. * @return The content type of the remote file. */ public String getContentType() { return _feedToPlayer.getContentDescriptor().getContentType(); } /** * Returns a stream to the buffered resource. * @return A stream to the buffered resource. */ public SourceStream[] getStreams() { return new SourceStream[] { _feedToPlayer }; } /** * Starts the connection thread used to download the remote file. */ public void start() throws IOException { //If the save stream is null, we have already completely downloaded //the file. if (_saveStream != null) { //Open the connection thread to finish downloading the file. _loaderThread = new ConnectionThread(); _loaderThread.start(); } } /** * Stop the connection thread. */ public void stop() throws IOException { //Set the boolean flag to stop the thread. _stop = true; } /** * @see javax.microedition.media.Controllable#getControl(String) */ public Control getControl(String controlType) { // No implemented Controls. return null; } /** * @see javax.microedition.media.Controllable#getControls() */ public Control[] getControls() { // No implemented Controls. return null; } /** * Force the lower level stream to a given content type. Must be called * before the connect function in order to work. * @param contentType The content type to use. */ public void setContentType(String contentType) { _forcedContentType = contentType; } /** * A stream to the buffered media resource. */ private final class LimitedRateSourceStream implements SourceStream { /** A stream to the local copy of the remote resource. */ private SharedInputStream _baseSharedStream; /** Describes the content type of the media file. */ private ContentDescriptor _contentDescriptor; /** * Constructor. Creates a LimitedRateSourceStream from * the given InputStream. * @param inputStream The input stream used to create a new reader. * @param contentType The content type of the remote file. */ LimitedRateSourceStream(InputStream inputStream, String contentType) { System.out.println("[LimitedRateSoruceStream]---------- 1"); _baseSharedStream = SharedInputStream.getSharedInputStream(inputStream); System.out.println("[LimitedRateSoruceStream]---------- 2"); _contentDescriptor = new ContentDescriptor(contentType); System.out.println("[LimitedRateSoruceStream]---------- 3"); } /** * Returns the content descriptor for this stream. * @return The content descriptor for this stream. */ public ContentDescriptor getContentDescriptor() { return _contentDescriptor; } /** * Returns the length provided by the connection. * @return long The length provided by the connection. */ public long getContentLength() { return _fileConnection.totalSize(); } /** * Returns the seek type of the stream. */ public int getSeekType() { return RANDOM_ACCESSIBLE; //return SEEKABLE_TO_START; } /** * Returns the maximum size (in bytes) of a single read. */ public int getTransferSize() { return _readLimit; } /** * Writes bytes from the buffer into a byte array for playback. * @param bytes The buffer into which the data is read. * @param off The start offset in array b at which the data is written. * @param len The maximum number of bytes to read. * @return the total number of bytes read into the buffer, or -1 if * there is no more data because the end of the stream has been reached. * @throws IOException */ public int read(byte[] bytes, int off, int len) throws IOException { System.out.println("[LimitedRateSoruceStream]---------- 5"); System.out.println("Read Request for: " + len + " bytes"); //Limit bytes read to our readLimit. int readLength = len; System.out.println("[LimitedRateSoruceStream]---------- 6"); if (readLength > getReadLimit()) { readLength = getReadLimit(); } //The number of available byes in the buffer. int available; //A boolean flag indicating that the thread should pause //until the buffer has increased sufficiently. boolean paused = false; System.out.println("[LimitedRateSoruceStream]---------- 7"); for (;;) { available = _baseSharedStream.available(); System.out.println("[LimitedRateSoruceStream]---------- 8"); if (_downloadComplete) { //Ignore all restrictions if downloading is complete. System.out.println("Complete, Reading: " + len + " - Available: " + available); return _baseSharedStream.read(bytes, off, len); } else if(_bufferingComplete) { if (paused && available > getResumeBytes()) { //If the video is paused due to buffering, but the //number of available byes is sufficiently high, //resume playback of the media. System.out.println("Resuming - Available: " + available); paused = false; return _baseSharedStream.read(bytes, off, readLength); } else if(!paused && (available > getPauseBytes() || available > readLength)) { //We have enough information for this media playback. if (available < getPauseBytes()) { //If the buffer is now insufficient, set the //pause flag. paused = true; } System.out.println("Reading: " + readLength + " - Available: " + available); return _baseSharedStream.read(bytes, off, readLength); } else if(!paused) { //Set pause until loaded enough to resume. paused = true; } } else { //We are not ready to start yet, try sleeping to allow the //buffer to increase. try { Thread.sleep(500); } catch (Exception e) { System.err.println(e.getMessage()); } } } } /** * @see javax.microedition.media.protocol.SourceStream#seek(long) */ public long seek(long where) throws IOException { _baseSharedStream.setCurrentPosition((int) where); return _baseSharedStream.getCurrentPosition(); } /** * @see javax.microedition.media.protocol.SourceStream#tell() */ public long tell() { return _baseSharedStream.getCurrentPosition(); } /** * Close the stream. * @throws IOException */ void close() throws IOException { _baseSharedStream.close(); } /** * @see javax.microedition.media.Controllable#getControl(String) */ public Control getControl(String controlType) { // No implemented controls. return null; } /** * @see javax.microedition.media.Controllable#getControls() */ public Control[] getControls() { // No implemented controls. return null; } } /** * A thread which downloads the remote file and writes it to the local file. */ private final class ConnectionThread extends Thread { /** * Download the remote media file, then write it to the local * file. * @see java.lang.Thread#run() */ public void run() { try { byte[] data = new byte[READ_CHUNK]; int len = 0; //Until we reach the end of the file. while (-1 != (len = _readAhead.read(data))) { _totalRead += len; if (!_bufferingComplete && _totalRead > getStartBuffer()) { //We have enough of a buffer to begin playback. _bufferingComplete = true; System.out.println("Initial Buffering Complete"); } if (_stop) { //Stop reading. return; } } System.out.println("Downloading Complete"); System.out.println("Total Read: " + _totalRead); //If the downloaded data is not the same size //as the remote file, something is wrong. if (_totalRead != _fileConnection.totalSize()) { System.err.println("* Unable to Download entire file *"); } _downloadComplete = true; _readAhead.setCurrentPosition(0); //Write downloaded data to the local file. while (-1 != (len = _readAhead.read(data))) { _saveStream.write(data); } } catch (Exception e) { System.err.println(e.toString()); } } } /** * Gets the minimum forward byte buffer which must be maintained in * order for the video to keep playing. * @return The pause byte buffer. */ int getPauseBytes() { return _pauseBytes; } /** * Sets the minimum forward buffer which must be maintained in order * for the video to keep playing. * @param pauseBytes The new pause byte buffer. */ void setPauseBytes(int pauseBytes) { _pauseBytes = pauseBytes; } /** * Gets the maximum size (in bytes) of a single read. * @return The maximum size (in bytes) of a single read. */ int getReadLimit() { return _readLimit; } /** * Sets the maximum size (in bytes) of a single read. * @param readLimit The new maximum size (in bytes) of a single read. */ void setReadLimit(int readLimit) { _readLimit = readLimit; } /** * Gets the minimum forward byte buffer required to resume * playback after a pause. * @return The resume byte buffer. */ int getResumeBytes() { return _resumeBytes; } /** * Sets the minimum forward byte buffer required to resume * playback after a pause. * @param resumeBytes The new resume byte buffer. */ void setResumeBytes(int resumeBytes) { _resumeBytes = resumeBytes; } /** * Gets the minimum number of bytes that must be buffered before the * media file will begin playing. * @return The start byte buffer. */ int getStartBuffer() { return _startBuffer; } /** * Sets the minimum number of bytes that must be buffered before the * media file will begin playing. * @param startBuffer The new start byte buffer. */ void setStartBuffer(int startBuffer) { _startBuffer = startBuffer; } } And in this way i use it: LimitedRateStreamingSource source = new LimitedRateStreamingSource("file:///SDCard/music3.mp3"); source.setContentType("audio/mpeg"); mediaPlayer = javax.microedition.media.Manager.createPlayer(source); mediaPlayer.addPlayerListener(this); mediaPlayer.realize(); mediaPlayer.prefetch(); After start i use mediaPlayer.getDuration it returns lets say around 24:22 (the inbuild media player in the blackberry say the file length is 4:05) I tried to get the duration in the listener and there unfortunatly returned around 64 minutes, so im sure something is not good inside the datasoruce....

  Read the article

• C#: BackgroundWorker cloning resources?

  - by Dav

  The problem I've been struggling with this partiular problem for two days now and just run out of ideas. A little... background: we have a WinForms app that needs to access a database, construct a list of related in-memory objects from that data, and then display on a DataGridView. Important point is that we first populate an app-wide cache (List), and then create a mirror of the cache local to the form on which the DGV lives (using List constructor param). Because fetching the data takes a good few seconds (DB sits on a LAN server) to load, we decided to use a BackgroundWorker, and only refresh the DGV once the data is loaded. However, it seems that doing the loading via a BGW results in some memory leak... or an error on my part. When loaded using a blocking method call, the app consumes about 30MB of RAM; with a BGW this jumps to 80MB! While it may not seem as much anyway, our clients are not too happy about it. Relevant code Form private void MyForm_Load(object sender, EventArgs e) { MyRepository.Instance.FinishedEvent += RefreshCache; } private void RefreshCache(object sender, EventArgs e) { dgvProducts.DataSource = new List<MyDataObj>(MyRepository.Products); } Repository private static List<MyDataObj> Products { get; set; } public event EventHandler ProductsLoaded; public void GetProductsSync() { List<MyDataObj> p; using (MyL2SDb db = new MyL2SDb(MyConfig.ConnectionString)) { p = db.PRODUCTS .Select(p => new MyDataObj {Id = p.ID, Description = p.DESCR}) .ToList(); } Products = p; // tell the form to refresh UI if (ProductsLoaded != null) ProductsLoaded(this, null); } public void GetProductsAsync() { using (BackgroundWorker myWorker = new BackgroundWorker()) { myWorker.DoWork += delegate { List<MyDataObj> p; using (MyL2SDb db = new MyL2SDb(MyConfig.ConnectionString)) { p = db.PRODUCTS .Select(p => new MyDataObj {Id = p.ID, Description = p.DESCR}) .ToList(); } Products = p; }; // tell the form to refresh UI when finished myWorker.RunWorkerCompleted += GetProductsCompleted; myWorker.RunWorkerAsync(); } } private void GetProductsCompleted(object sender, RunWorkerCompletedEventArgs e) { if (ProductsLoaded != null) ProductsLoaded(this, null); } End! GetProductsSync or GetProductsAsync are called on the main thread, not shown above. Could it be that the GarbageCollector just gets lost with two threads? Or is it the task manager that shows incorrect values? Will be greateful for any responses, suggestions, criticism.

  Read the article

• Declare private static members in F#?

  - by acidzombie24

  I decided to port the class in C# below to F# as an exercise. It was difficult. I only notice three problems 1) Greet is visible 2) I can not get v to be a static class variable 3) I do not know how to set the greet member in the constructor. How do i fix these? The code should be similar enough that i do not need to change any C# source. ATM only Test1.v = 21; does not work C# using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace CsFsTest { class Program { static void Main(string[] args) { Test1.hi("stu"); new Test1().hi(); Test1.v = 21; var a = new Test1("Stan"); a.hi(); a.a = 9; Console.WriteLine("v = {0} {1} {2}", a.a, a.b, a.NotSTATIC()); } } class Test1 { public int a; public int b { get { return a * 2; } } string greet = "User"; public static int v; public Test1() {} public Test1(string name) { greet = name; } public static void hi(string greet) { Console.WriteLine("Hi {0}", greet); } public void hi() { Console.WriteLine("Hi {0} #{1}", greet, v); } public int NotSTATIC() { return v; } } } F# namespace CsFsTest type Test1 = (* public int a; public int b { get { return a * 2; } } string greet = "User"; public static int v; *) [<DefaultValue>] val mutable a : int member x.b = x.a * 2 member x.greet = "User" (*!! Needs to be private *) [<DefaultValue>] val mutable v : int (*!! Needs to be static *) (* public Test1() {} public Test1(string name) { greet = name; } *) new () = {} new (name) = { } (* public static void hi(string greet) { Console.WriteLine("Hi {0}", greet); } public void hi() { Console.WriteLine("Hi {0} #{1}", greet, v); } public int NotSTATIC() { return v; } *) static member hi(greet) = printfn "hi %s" greet member x.hi() = printfn "hi %s #%i" x.greet x.v member x.NotSTATIC() = x.v

  Read the article

• WPF ListView Data Binding wont synchronize

  - by Aviatrix

  my listview will display only the item that its added by the constructor and it wont add the items that i add dynamically public class PostList : ObservableCollection<PostData> { public PostList() : base() { Add(new PostData("Isak", "Dinesen")); // Add(new PostData("Victor", "Hugo")); // Add(new PostData("Jules", "Verne")); } public void AddToList (string[] data){ string username2, msg; msg = data[0]; username2 = data[1]; Add(new PostData(msg, username2)); } } public class PostData { private string Username; private string Msg; private string Avatar; private string LinkAttached; private string PicAttached; private string VideoAttached; public PostData(string msg ,string username, string avatar=null, string link=null,string pic=null ,string video=null) { this.Username = username; this.Msg = msg; this.Avatar = avatar; this.LinkAttached = link; this.PicAttached = pic; this.VideoAttached = video; } public string pMsg { get { return Msg; } set { Msg = value; } } public string pUsername { get { return Username; } set { Username = value; } } ..... ..... } Xaml <ListView x:Name="PostListView" BorderThickness="0" MinHeight="300" Background="{x:Null}" BorderBrush="{x:Null}" Foreground="{x:Null}" VerticalContentAlignment="Top" ScrollViewer.HorizontalScrollBarVisibility="Disabled" ScrollViewer.VerticalScrollBarVisibility="Disabled" IsSynchronizedWithCurrentItem="True" MinWidth="332" SelectedIndex="0" SelectionMode="Extended" AlternationCount="1" ItemsSource="{Binding Source={StaticResource PostListData}}"> <ListView.ItemTemplate> <DataTemplate> <DockPanel x:Name="SinglePost" VerticalAlignment="Top" ScrollViewer.CanContentScroll="True" ClipToBounds="True" Width="333" Height="70" d:LayoutOverrides="VerticalAlignment" d:IsEffectDisabled="True"> <StackPanel x:Name="AvatarNickHolder" Width="60"> <Label x:Name="Nick" HorizontalAlignment="Center" Margin="5,0" VerticalAlignment="Top" Height="15" Content="{Binding Path=pUsername}" FontFamily="Arial" FontSize="10.667" Padding="5,0"/> <Image x:Name="Avatar" HorizontalAlignment="Center" Margin="5,0,5,5" VerticalAlignment="Top" Width="50" Height="50" IsHitTestVisible="False" Source="1045443356IMG_0972.jpg" Stretch="UniformToFill"/> </StackPanel> <TextBlock x:Name="userPostText" Margin="0,0,5,0" VerticalAlignment="Center" FontSize="10.667" Text="{Binding Path=pMsg}" TextWrapping="Wrap"/> </DockPanel> </DataTemplate> </ListView.ItemTemplate> </ListView>

  Read the article

• Hidden Features of PHP?

  - by George Mauer

  EDIT: This didn't really start as a hidden features of PHP topic, but thats what it ended up as, so go nuts. I know this sounds like a point-whoring question but let me explain where I'm coming from. Out of college I got a job at a PHP shop. I worked there for a year and a half and thought that I had learned all there was to learn about programming. Then I got a job as a one-man internal development shop at a sizable corporation where all the work was in C#. In my commitment to the position I started reading a ton of blogs and books and quickly realized how wrong I was to think I knew everything. I learned about unit testing, dependency injection and decorator patterns, the design principle of loose coupling, the composition over inheritance debate, and so on and on and on - I am still very much absorbing it all. Needless to say my programming style has changed entirely in the last year. Now I find myself picking up a php project doing some coding for a friend's start-up and I feel completely constrained as opposed to programming in C#. It really bothers me that all variables at a class scope have to be referred to by appending '$this-' . It annoys me that none of the IDEs that I've tried have very good intellisense and that my SimpleTest unit tests methods have to start with the word 'test'. It drives me crazy that dynamic typing keeps me from specifying implicitly which parameter type a method expects, and that you have to write a switch statement to do method overloads. I can't stand that you can't have nested namespaces and have to use the :: operator to call the base class's constructor. Now I have no intention of starting a PHP vs C# debate, rather what I mean to say is that I'm sure there are some PHP features that I either don't know about or know about yet fail to use properly. I am set in my C# universe and having trouble seeing outside the glass bowl. So I'm asking, what are your favorite features of PHP? What are things you can do in it that you can't or are more difficult in the .Net languages?

  Read the article

• Help with a logic problem

  - by Stradigos

  I'm having a great deal of difficulty trying to figure out the logic behind this problem. I have developed everything else, but I really could use some help, any sort of help, on the part I'm stuck on. Back story: *A group of actors waits in a circle. They "count off" by various amounts. The last few to audition are thought to have the best chance of getting the parts and becoming stars. Instead of actors having names, they are identified by numbers. The "Audition Order" in the table tells, reading left-to-right, the "names" of the actors who will be auditioned in the order they will perform.* Sample output: etc, all the way up to 10. What I have so far: using System; using System.Collections; using System.Text; namespace The_Last_Survivor { class Program { static void Main(string[] args) { //Declare Variables int NumOfActors = 0; System.DateTime dt = System.DateTime.Now; int interval = 3; ArrayList Ring = new ArrayList(10); //Header Console.Out.WriteLine("Actors\tNumber\tOrder"); //Add Actors for (int x = 1; x < 11; x++) { NumOfActors++; Ring.Insert((x - 1), new Actor(x)); foreach (Actor i in Ring) { Console.Out.WriteLine("{0}\t{1}\t{2}", NumOfActors, i, i.Order(interval, x)); } Console.Out.WriteLine("\n"); } Console.In.Read(); } public class Actor { //Variables protected int Number; //Constructor public Actor(int num) { Number = num; } //Order in circle public string Order(int inter, int num) { //Variable string result = ""; ArrayList myArray = new ArrayList(num); //Filling Array for (int i = 0; i < num; i++) myArray.Add(i + 1); //Formula foreach (int element in myArray) { if (element == inter) { result += String.Format(" {0}", element); myArray.RemoveAt(element); } } return result; } //String override public override string ToString() { return String.Format("{0}", Number); } } } } The part I'm stuck on is getting some math going that does this: Can anyone offer some guidance and/or sample code?

  Read the article

< Previous Page | 137 138 139 140 141 142 143 144 145 146 147 148  | Next Page >