Search Results

Search found 21054 results on 843 pages for 'the void'.

Page 65/843 | < Previous Page | 61 62 63 64 65 66 67 68 69 70 71 72  | Next Page >

  • Pointers to class fields

    - by newbie_cpp
    My task is as follows : Using pointers to class fields, create menu allowing selection of ice, that Person can buy in Ice shop. Buyer will be charged with waffel and ice costs. Selection of ice and charging buyers account must be shown in program. Here's my Person class : #include <iostream> using namespace std; class Iceshop { const double waffel_price = 1; public: } class Person { static int NUMBER; char* name; int age; const int number; double plus, minus; public: class Account { int number; double resources; public: Account(int number, double resources) : number(number), resources(resources) {} } Person(const char* n, int age) : name(strcpy(new char[strlen(n)+1],n)), number(++NUMBER), plus(0), minus(0), age(age) {} Person::~Person(){ cout << "Destroying resources" << endl; delete [] name; } friend void show(Person &p); int* take_age(){ return &age; } char* take_name(){ return name; } void init(char* n, int a) { name = n; age = a; } Person& remittance(double d) { plus += d; return *this; } Person& paycheck(double d) { minus += d; return *this; } Account* getAccount(); }; int Person:: Person::Account* Person::getAccount() { return new Account(number, plus - minus); } void Person::Account::remittance(double d){ resources = resources + d; } void Person::Account::paycheck(double d){ resources = resources - d; } void show(Person *p){ cout << "Name: " << p->take_name() << "," << "age: " << p->take_age() << endl; } int main(void) { Person *p = new Person; p->init("Mary", 25); show(p); p->remittance(100); system("PAUSE"); return 0; } How to start this task ? Where and in what form should I store menu options ?

    Read the article

  • What would be a correct implemantation of JSF Converter if I need to get an Integer to run a query?

    - by Ignacio
    HI here's my code: List.xhmtl <h:selectOneMenu value="#{produtosController.items}"> <f:selectItems value="#{produtosController.itemsAvailableSelectOne}"/> </h:selectOneMenu> <h:commandButton action="#{produtosController.createByCodigos}" value="Buscar" /> My Controller Class with innner Converter implemantation @ManagedBean (name="produtosController") @SessionScoped public class ProdutosController { private Produtos current; private DataModel items = null; @EJB private controladores.ProdutosFacade ejbFacade; private PaginationHelper pagination; private int selectedItemIndex; public ProdutosController() { } public Produtos getSelected() { if (current == null) { current = new Produtos(); selectedItemIndex = -1; } return current; } private ProdutosFacade getFacade() { return ejbFacade; } public PaginationHelper getPagination() { if (pagination == null) { pagination = new PaginationHelper(10) { @Override public int getItemsCount() { return getFacade().count(); } @Override public DataModel createPageDataModel() { return new ListDataModel(getFacade().findRange(new int[]{getPageFirstItem(), getPageFirstItem()+getPageSize()})); } }; } return pagination; } public String prepareList() { recreateModel(); return "List"; } public String prepareView() { current = (Produtos)getItems().getRowData(); selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex(); return "View"; } public String prepareCreate() { current = new Produtos(); selectedItemIndex = -1; return "Create"; } public String create() { try { getFacade().create(current); JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("ProdutosCreated")); return prepareCreate(); } catch (Exception e) { JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured")); return null; } } public String createByMarcas() { items = new ListDataModel(ejbFacade.findByMarcas(current.getIdMarca())); updateCurrentItem(); return "List"; } public String createByModelos() { items = new ListDataModel(ejbFacade.findByModelos(current.getIdModelo())); updateCurrentItem(); return "List"; } public String createByCodigos(){ items = new ListDataModel(ejbFacade.findByCodigo(current.getCodigo())); updateCurrentItem(); return "List"; } public String prepareEdit() { current = (Produtos)getItems().getRowData(); selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex(); return "Edit"; } public String update() { try { getFacade().edit(current); JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("ProdutosUpdated")); return "View"; } catch (Exception e) { JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured")); return null; } } public String destroy() { current = (Produtos)getItems().getRowData(); selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex(); performDestroy(); recreateModel(); return "List"; } public String destroyAndView() { performDestroy(); recreateModel(); updateCurrentItem(); if (selectedItemIndex >= 0) { return "View"; } else { // all items were removed - go back to list recreateModel(); return "List"; } } private void performDestroy() { try { getFacade().remove(current); JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("ProdutosDeleted")); } catch (Exception e) { JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured")); } } private void updateCurrentItem() { int count = getFacade().count(); if (selectedItemIndex >= count) { // selected index cannot be bigger than number of items: selectedItemIndex = count-1; // go to previous page if last page disappeared: if (pagination.getPageFirstItem() >= count) { pagination.previousPage(); } } if (selectedItemIndex >= 0) { current = getFacade().findRange(new int[]{selectedItemIndex, selectedItemIndex+1}).get(0); } } public DataModel getItems() { if (items == null) { items = getPagination().createPageDataModel(); } return items; } private void recreateModel() { items = null; } public String next() { getPagination().nextPage(); recreateModel(); return "List"; } public String previous() { getPagination().previousPage(); recreateModel(); return "List"; } public SelectItem[] getItemsAvailableSelectMany() { return JsfUtil.getSelectItems(ejbFacade.findAll(), false); } public SelectItem[] getItemsAvailableSelectOne() { return JsfUtil.getSelectItems(ejbFacade.findAll(), true); } @FacesConverter(forClass=Produtos.class) public static class ProdutosControllerConverter implements Converter{ public Object getAsObject(FacesContext facesContext, UIComponent component, String value) { if (value == null || value.length() == 0) { return null; } ProdutosController controller = (ProdutosController)facesContext.getApplication().getELResolver(). getValue(facesContext.getELContext(), null, "produtosController"); return controller.ejbFacade.find(getKey(value)); } java.lang.Integer getKey(String value) { java.lang.Integer key; key = Integer.decode(value); return key; } String getStringKey(java.lang.Integer value) { StringBuffer sb = new StringBuffer(); sb.append(value); return sb.toString(); } public String getAsString(FacesContext facesContext, UIComponent component, Object object) { if (object == null) { return null; } if (object instanceof Produtos) { Produtos o = (Produtos) object; return getStringKey(o.getCodigo()); } else { throw new IllegalArgumentException("object " + object + " is of type " + object.getClass().getName() + "; expected type: "+ProdutosController.class.getName()); } } } } and my EJB @Entity @ViewScoped @Table(name = "produtos") @NamedQueries({ @NamedQuery(name = "Produtos.findAll", query = "SELECT p FROM Produtos p"), @NamedQuery(name = "Produtos.findById", query = "SELECT p FROM Produtos p WHERE p.id = :id"), @NamedQuery(name = "Produtos.findByCodigo", query = "SELECT p FROM Produtos p WHERE p.codigo = :codigo"), @NamedQuery(name = "Produtos.findByDescripcion", query = "SELECT p FROM Produtos p WHERE p.descripcion = :descripcion"), @NamedQuery(name = "Produtos.findByImagen", query = "SELECT p FROM Produtos p WHERE p.imagen = :imagen"), @NamedQuery(name = "Produtos.findByMarcas", query="SELECT m FROM Produtos m WHERE m.idMarca.id = :idMarca"), @NamedQuery(name = "Produtos.findByModelos", query="SELECT m FROM Produtos m WHERE m.idModelo.id = :idModelo")}) public class Produtos implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Basic(optional = false) @Column(name = "id") private Integer id; @Column(name = "codigo") private Integer codigo; @Column(name = "descripcion") private String descripcion; @Column(name = "imagen") private String imagen; @JoinColumn(name = "id_modelo", referencedColumnName = "id") @ManyToOne(optional = false) private Modelos idModelo; @JoinColumn(name = "id_marca", referencedColumnName = "id") @ManyToOne(optional = false) private Marcas idMarca; public Produtos() { } public Produtos(Integer id) { this.id = id; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getCodigo() { return codigo; } public void setCodigo(Integer codigo) { this.codigo = codigo; } public String getDescripcion() { return descripcion; } public void setDescripcion(String descripcion) { this.descripcion = descripcion; } public String getImagen() { return imagen; } public void setImagen(String imagen) { this.imagen = imagen; } public Modelos getIdModelo() { return idModelo; } public void setIdModelo(Modelos idModelo) { this.idModelo = idModelo; } public Marcas getIdMarca() { return idMarca; } public void setIdMarca(Marcas idMarca) { this.idMarca = idMarca; } @Override public int hashCode() { int hash = 0; hash += (id != null ? id.hashCode() : 0); return hash; } @Override public boolean equals(Object object) { // TODO: Warning - this method won't work in the case the id fields are not set if (!(object instanceof Produtos)) { return false; } Produtos other = (Produtos) object; if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) { return false; } return true; } @Override public String toString() { return "" + codigo + ""; } }

    Read the article

  • How to prevent duplicates, macro or something?

    - by blez
    Well, the problem is that I've got a lot of code like this for each event passed to the GUI, how can I shortify this? Macros wont do the work I guess. Is there a more generic way to do something like a 'template' ? private delegate void DownloadProgressDelegate(object sender, DownloaderProgressArgs e); void DownloadProgress(object sender, DownloaderProgressArgs e) { if (this.InvokeRequired) { this.BeginInvoke(new DownloadProgressDelegate(DownloadProgress), new object[] { sender, e }); return; } label2.Text = d.speedOutput.ToString(); } private delegate void DownloadSpeedDelegate(object sender, DownloaderProgressArgs e); void DownloadSpeed(object sender, DownloaderProgressArgs e) { if (this.InvokeRequired) { this.BeginInvoke(new DownloadSpeedDelegate(DownloadSpeed), new object[] { sender, e }); return; } string speed = ""; speed = (e.DownloadSpeed / 1024).ToString() + "kb/s"; label3.Text = speed; }

    Read the article

  • RAII: Initializing data member in const method

    - by Thomas Matthews
    In RAII, resources are not initialized until they are accessed. However, many access methods are declared constant. I need to call a mutable (non-const) function to initialize a data member. Example: Loading from a data base struct MyClass { int get_value(void) const; private: void load_from_database(void); // Loads the data member from database. int m_value; }; int MyClass :: get_value(void) const { static bool value_initialized(false); if (!value_initialized) { // The compiler complains about this call because // the method is non-const and called from a const // method. load_from_database(); } return m_value; } My primitive solution is to declare the data member as mutable. I would rather not do this, because it suggests that other methods can change the member. How would I cast the load_from_database() statement to get rid of the compiler errors?

    Read the article

  • Drill down rss reader iphone

    - by bing
    Hi everyone, I have made a simple rss reader. The app loads an xml atom file in an array. Now I have added categories to my atom feed, which are first loaded in the array What is the best way to add drill down functionality programmatically. Now only the categories are loaded into the array and displayed. This is the implementation code ..... loading xml file <snip> ..... - (void)parserDidStartDocument:(NSXMLParser *)parser { NSLog(@"found file and started parsing"); } - (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError { NSString * errorString = [NSString stringWithFormat:@"Unable to download story feed from web site (Error code %i )", [parseError code]]; NSLog(@"error parsing XML: %@", errorString); UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:@"Error loading content" message:errorString delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil]; [errorAlert show]; } - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{ //NSLog(@"found this element: %@", elementName); currentElement = [elementName copy]; if ([elementName isEqualToString:@"entry"]) { // clear out our story item caches... Categoryentry = [[NSMutableDictionary alloc] init]; currentID = [[NSMutableString alloc] init]; currentTitle = [[NSMutableString alloc] init]; currentSummary = [[NSMutableString alloc] init]; currentContent = [[NSMutableString alloc] init]; } } - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{ //NSLog(@"ended element: %@", elementName); if ([elementName isEqualToString:@"entry"]) { // save values to an entry, then store that item into the array... [Categoryentry setObject:currentTitle forKey:@"title"]; [Categoryentry setObject:currentID forKey:@"id"]; [Categoryentry setObject:currentSummary forKey:@"summary"]; [Categoryentry setObject:currentContent forKey:@"content"]; [categories addObject:[Categoryentry copy]]; NSLog(@"adding category: %@", currentTitle); } } - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{ //NSLog(@"found characters: %@", string); // save the characters for the current item... if ([currentElement isEqualToString:@"title"]) { [currentTitle appendString:string]; } else if ([currentElement isEqualToString:@"id"]) { [currentID appendString:string]; } else if ([currentElement isEqualToString:@"summary"]) { [currentSummary appendString:string]; } else if ([currentElement isEqualToString:@"content"]) { [currentContent appendString:string]; } } - (void)parserDidEndDocument:(NSXMLParser *)parser { [activityIndicator stopAnimating]; [activityIndicator removeFromSuperview]; NSLog(@"all done!"); NSLog(@"categories array has %d entries", [categories count]); [newsTable reloadData]; }

    Read the article

  • use callback function to report stack backtrace

    - by user353394
    Assume I have the following: typedef struct { char *name; char binding; int address; } Fn_Symbol //definition of function symbol static Fn_Symbol *fnSymbols; //array of function symbols in a file statc int total; //number of symbol functions in the array and file static void PrintBacktrace(int sigum, siginfo_t * siginfo, void *context) { printf("\nSignal received %d (%s)\n", signum, strsignal(signum)); const int eip_index = 14; void *eip = (void *)((struct ucontext *)context)->uc_mcontext.gregs[eip_index]; printf("Error at [%p] %s (+0x%x), eip, fnName, offset from start); //????? exit(0); } I have this so far, but what is the best way using the fnSymbols static global pointer to identify the function where the error occured and then back trace through the stack to identify each calling function by address, name, and offset?

    Read the article

  • Reference Value Parameter VS Return value which one is good?

    - by CodeYun
    When we want to modify some value in one object we may use two different methods, just want to know which one is better or there is no big different between them. void SomeMethod() { UserInfo newUser = New UserInfo(); ModifyUserInfo(newUser); //Modify UserInfo after calling void method GetUserInfo } void ModifyUserInfo(UseerInfo userInfo) { userInfo.UserName = "User Name"; ..... } void SomeMethod() { UserInfo newUser = New UserInfo(); //Assign new userinfo explicitly newUser = GetUserInfo(newUser); } UserInfo ModifyUserInfo(UseerInfo userInfo) { userInfo.UserName = "User Name"; ..... return userInfo; }

    Read the article

  • Do I need multiple template specializations if I want to specialize for several kinds of strings?

    - by romkyns
    For example: template<typename T> void write(T value) { mystream << value; } template<> void write<const char*>(const char* value) { write_escaped(mystream, value); } template<> void write<char*>(char* value) { write_escaped(mystream, value); } template<> void write<std::string>(std::string value) { write_escaped(mystream.c_str(), value); } This looks like I'm doing it wrong, especially the two variants for const and non-const char*. However I checked that if I only specialize for const char * then passing a char * variable will invoke the non-specialized version, when called like this in VC++10: char something[25]; strcpy(something, "blah"); write(something); What would be the proper way of doing this?

    Read the article

  • java bubblesort with acm dialog

    - by qzar
    Hi, the program gives following exception: Exception in thread "main" java.lang.NullPointerException at myclasses.BubbleSort.run(BubbleSort.java:42) at acm.program.Program.runHook(Program.java:1519) at acm.program.Program.startRun(Program.java:1508) at acm.program.Program.start(Program.java:729) at myclasses.BubbleSort.main(BubbleSort.java:49) what is wrong? thank you very much! package myclasses; import acm.program.DialogProgram; public class BubbleSort extends DialogProgram { int[] array; public int[] getArray() { return array; } public void setArray(int[] array) { this.array = array; } void swap(int firstPos, int secondPos) { int temp = array[firstPos]; array[firstPos] = array[secondPos]; array[secondPos] = temp; } public void bubblesort() { int i, j, k; for (i = 1; i < array.length; i++) { j = i; k = array[i]; while (j > 0 && array[j - 1] > k) { array[j] = array[j - 1]; --j; } array[j] = k; } } public void run() { BubbleSort a = new BubbleSort(); a.setArray(new int[] {1, 3, 5, 7, 6, 2}); a.bubblesort(); StringBuffer sb = new StringBuffer(a.array.length * 2); for (int i = 0; i < getArray().length; i++) sb.append(getArray()[i]).append(" "); println(sb); } public static void main(String[] args) { new BubbleSort().start(args); } }

    Read the article

  • iphone web service access

    - by malleswar
    Hi, I have .net webservice methods login and summary. After getting the result from login, I need to show second view and need to call summary method. I am following this tutorial. http://icodeblog.com/2008/11/03/iphone-programming-tutorial-intro-to-soap-web-services/ I created two new classes loginaccess.h and loginaccess.m. @implementation LoginAccess @synthesize ResultString,webData, soapResults, xmlParser; -(NSString*)LoginCheck:(NSString*)userName:(NSString*)pwd { NSString *soapMessage = [NSString stringWithFormat: @"\n" "\n" "\n" "\n" "%@" "%@" "" "\n" "\n",userName,pwd ]; NSLog(soapMessage); NSURL *url = [NSURL URLWithString:@"http://www.XXXXXXXXX.com/service.asmx"]; NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url]; NSString *msgLength = [NSString stringWithFormat:@"%d", [soapMessage length]]; [theRequest addValue: @"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"]; [theRequest addValue: @"http://XXXXXXXXm/Login" forHTTPHeaderField:@"SOAPAction"]; [theRequest addValue: msgLength forHTTPHeaderField:@"Content-Length"]; [theRequest setHTTPMethod:@"POST"]; [theRequest setHTTPBody: [soapMessage dataUsingEncoding:NSUTF8StringEncoding]]; NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self]; if( theConnection ) { webData = [[NSMutableData data] retain]; } else { NSLog(@"theConnection is NULL"); } //[nameInput resignFirstResponder]; return ResultString; } -(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { [webData setLength: 0]; } -(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { [webData appendData:data]; } -(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { NSLog(@"ERROR with theConenction"); [connection release]; [webData release]; } -(void)connectionDidFinishLoading:(NSURLConnection *)connection { NSLog(@"DONE. Received Bytes: %d", [webData length]); NSString *theXML = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding]; NSLog(theXML); [theXML release]; if( xmlParser ) { [xmlParser release]; } xmlParser = [[NSXMLParser alloc] initWithData: webData]; [xmlParser setDelegate: self]; [xmlParser setShouldResolveExternalEntities: YES]; [xmlParser parse]; [connection release]; [webData release]; } -(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *) namespaceURI qualifiedName:(NSString *)qName attributes: (NSDictionary *)attributeDict { if( [elementName isEqualToString:@"LoginResult"]) { if(!soapResults) { soapResults = [[NSMutableString alloc] init]; } recordResults = TRUE; } } -(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { if( recordResults ) { [soapResults appendString: string]; } } -(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { if( [elementName isEqualToString:@"LoginResult"]) { recordResults = FALSE; ResultString = soapResults; NSLog(@"Login"); [VariableStore setStr:ResultString]; NSLog(soapResults); [soapResults release]; soapResults = nil; } } @end I am calling LoginCheck method and based on result I want to show the second view. Here after finishing of the button touch down event, it enter into did end element, so I am always getting nil value. If I use the same code controller it works fine as I push second view controller in didendelement. Please give me some samples to place the web service calls in differnt class and how to call them in viewcontrollers. Regards, Malleswar

    Read the article

  • Performance of C# method polymorphism with generics

    - by zildjohn01
    I noticed in C#, unlike C++, you can combine virtual and generic methods. For example: using System.Diagnostics; class Base { public virtual void Concrete() {Debug.WriteLine("base concrete");} public virtual void Generic<T>() {Debug.WriteLine("base generic");} } class Derived : Base { public override void Concrete() {Debug.WriteLine("derived concrete");} public override void Generic<T>() {Debug.WriteLine("derived generic");} } class App { static void Main() { Base x = new Derived(); x.Concrete(); x.Generic<PerformanceCounter>(); } } Given that any number of versions of Generic<T> could be instantiated, it doesn't look like the standard vtbl approach could be used to resolve method calls, and in fact it's not. Here's the generated code: x.Concrete(); mov ecx,dword ptr [ebp-8] mov eax,dword ptr [ecx] call dword ptr [eax+38h] x.Generic<PerformanceCounter>(); push 989A38h mov ecx,dword ptr [ebp-8] mov edx,989914h call 76A874F1 mov dword ptr [ebp-4],eax mov ecx,dword ptr [ebp-8] call dword ptr [ebp-4] The extra code appears to be looking up a dynamic vtbl according to the generic parameters, and then calling into it. Has anyone written about the specifics of this implementation? How well does it perform compared to the non-generic case?

    Read the article

  • Observer pattern and violation of Single Responsibility Principle

    - by Devil Jin
    I have an applet which repaints itself once the text has changed Design 1: //MyApplet.java public class MyApplet extends Applet implements Listener{ private DynamicText text = null; public void init(){ text = new DynamicText("Welcome"); } public void paint(Graphics g){ g.drawString(text.getText(), 50, 30); } //implement Listener update() method public void update(){ repaint(); } } //DynamicText.java public class DynamicText implements Publisher{ // implements Publisher interface methods //notify listeners whenever text changes } Isn't this a violation of Single Responsibility Principle where my Applet not only acts as Applet but also has to do Listener job. Same way DynamicText class not only generates the dynamic text but updates the registered listeners. Design 2: //MyApplet.java public class MyApplet extends Applet{ private AppletListener appLstnr = null; public void init(){ appLstnr = new AppletListener(this); // applet stuff } } // AppletListener.java public class AppletListener implements Listener{ private Applet applet = null; public AppletListener(Applet applet){ this.applet = applet; } public void update(){ this.applet.repaint(); } } // DynamicText public class DynamicText{ private TextPublisher textPblshr = null; public DynamicText(TextPublisher txtPblshr){ this.textPblshr = txtPblshr; } // call textPblshr.notifyListeners whenever text changes } public class TextPublisher implments Publisher{ // implements publisher interface methods } Q1. Is design 1 a SPR violation? Q2. Is composition a better choice here to remove SPR violation as in design 2.

    Read the article

  • c# Generic overloaded method dispatching ambiguous

    - by sebgod
    Hello, I just hit a situation where a method dispatch was ambiguous and wondered if anyone could explain on what basis the compiler (.NET 4.0.30319) chooses what overload to call interface IfaceA { } interface IfaceB<T> { void Add(IfaceA a); T Add(T t); } class ConcreteA : IfaceA { } class abstract BaseClassB<T> : IfaceB<T> { public virtual T Add(T t) { ... } public virtual void Add(IfaceA a) { ... } } class ConcreteB : BaseClassB<IfaceA> { // does not override one of the relevant methods } void code() { var concreteB = new ConcreteB(); // it will call void Add(IfaceA a) concreteB.Add(new ConcreteA()); } In any case, why does the compiler not warn me or even why does it compile? Thank you very much for any answers.

    Read the article

  • Saving data in custom class via AppDelegate

    - by redspike
    I can't seem to save data to a custom instance object in my AppDelegate. My custom class is very simple and is as follows: Person.h ... @interface Person : NSObject { int _age; } - (void) setAge: (int) age; - (int) age; @end Person.m #import "Person.h" @implementation Person - (void) setAge:(int) age { _age = age; } - (int) age { return _age; } @end I then create an instance of Person in the AppDelegate class: AppDelegate.h @class Person; @interface AccuTaxAppDelegate : NSObject <UIApplicationDelegate> { ... Person *person; } ... @property (nonatomic, retain) Person *person; @end AppDelegate.m ... #import "Person.h" @implementation AccuTaxAppDelegate ... @synthesize person; - (void)applicationDidFinishLaunching:(UIApplication *)application { // Override point for customization after app launch [window addSubview:[navigationController view]]; [window makeKeyAndVisible]; } - (void)applicationWillTerminate:(UIApplication *)application { // Save data if appropriate } #pragma mark - #pragma mark Memory management - (void)dealloc { [navigationController release]; [window release]; [person release]; [super dealloc]; } @end Finally, in my ViewController code I grab a handle on AppDelegate and then grab the person instance, but when I try to save the age it doesn't seem to work: MyViewController ... - (void)textFieldDidEndEditing:(UITextField *)textField { NSString *textAge = [textField text]; int age = [textAge intValue]; NSLog(@"Age from text field::%i", age); AppDelegate *appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate; Person *myPerson = (Person *)[appDelegate person]; NSLog(@"Age before setting: %i", [myPerson age]); [myPerson setAge:age]; NSLog(@"Age after setting: %i", [myPerson age]); [textAge release]; } ... The output of the above NSLogs are: [Session started at 2010-05-04 18:29:22 +0100.] 2010-05-04 18:29:28.260 AccuTax[16235:207] Age in text field:25 2010-05-04 18:29:28.262 AccuTax[16235:207] Age before setting: 0 2010-05-04 18:29:28.263 AccuTax[16235:207] Age after setting: 0 Any ideas why 'age' isn't being stored? I'm relatively new to Obj-C so please forgive me if I'm missing something very simple!

    Read the article

  • Help with method logic in Java, hw

    - by Crystal
    I have a Loan class that in its printPayment method, it prints the amortization table of a loan for a hw assignment. We are also to implement a print first payment method, and a print last payment method. Since my calculation is done in the printPayment method, I didn't know how I could get the value in the first or last iteration of the loop and print that amount out. One way I can think of is to write a new method that might return that value, but I wasn't sure if there was a better way. Here is my code: public abstract class Loan { public void setClient(Person client) { this.client = client; } public Person getClient() { return client; } public void setLoanId() { loanId = nextId; nextId++; } public int getLoanId() { return loanId; } public void setInterestRate(double interestRate) { this.interestRate = interestRate; } public double getInterestRate() { return interestRate; } public void setLoanLength(int loanLength) { this.loanLength = loanLength; } public int getLoanLength() { return loanLength; } public void setLoanAmount(double loanAmount) { this.loanAmount = loanAmount; } public double getLoanAmount() { return loanAmount; } public void printPayments() { double monthlyInterest; double monthlyPrincipalPaid; double newPrincipal; int paymentNumber = 1; double monthlyInterestRate = interestRate / 1200; double monthlyPayment = loanAmount * (monthlyInterestRate) / (1 - Math.pow((1 + monthlyInterestRate),( -1 * loanLength))); System.out.println("Payment Number | Interest | Principal | Loan Balance"); // amortization table while (loanAmount >= 0) { monthlyInterest = loanAmount * monthlyInterestRate; monthlyPrincipalPaid = monthlyPayment - monthlyInterest; newPrincipal = loanAmount - monthlyPrincipalPaid; loanAmount = newPrincipal; System.out.printf("%d, %.2f, %.2f, %.2f", paymentNumber++, monthlyInterest, monthlyPrincipalPaid, loanAmount); } } /* //method to print first payment public double getFirstPayment() { } method to print last payment public double getLastPayment() { }*/ private Person client; private int loanId; private double interestRate; private int loanLength; private double loanAmount; private static int nextId = 1; } Thanks!

    Read the article

  • No GPS Update retrieved? Problem in Code?

    - by poeschlorn
    Hello mates, I've got a serious problem with my GPS on my Nexus One: I wrote a kind of hello world with GPS, but the Toast that should be displayed isn't :( I don't know what I'm doing wrong...maybe you could help me getting this work. Here's my code: package gps.test; import android.app.Activity; import android.content.Context; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.widget.Toast; public class GPS extends Activity { private LocationManager lm; private LocationListener locationListener; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // ---use the LocationManager class to obtain GPS locations--- lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE); locationListener = new MyLocationListener(); lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 100, 1, locationListener); } private class MyLocationListener implements LocationListener { @Override public void onLocationChanged(Location loc) { if (loc != null) { Toast.makeText( getBaseContext(), "Location changed : Lat: " + loc.getLatitude() + " Lng: " + loc.getLongitude(), Toast.LENGTH_SHORT).show(); } } @Override public void onProviderDisabled(String provider) { // TODO Auto-generated method stub } @Override public void onProviderEnabled(String provider) { // TODO Auto-generated method stub } @Override public void onStatusChanged(String provider, int status, Bundle extras) { // TODO Auto-generated method stub } } } Theoretically there should be a new toast every 100 milliseconds, shouldn't it? Or at least, when I change my position by one meter!? I've no idea why it doesn't. I must admit I'm new to the topic, maybe I've missed something? It would be great if you could give me a hint :) nice greetings, poeschlorn

    Read the article

  • Java abstract visitor - guarantueed to succeed? If so, why?

    - by disown
    I was dealing with hibernate, trying to figure out the run-time class behind proxied instances by using the visitor pattern. I then came up with an AbstractVisitable approach, but I wonder if it will always produce correct results. Consider the following code: interface Visitable { public void accept(Visitor v); } interface Visitor { public void visit(Visitable visitorHost); } abstract class AbstractVisitable implements Visitable { @Override public void accept(Visitor v) { v.visit(this); } } class ConcreteVisitable extends AbstractVisitable { public static void main(String[] args) { final Visitable visitable = new ConcreteVisitable(); final Visitable proxyVisitable = (Visitable) Proxy.newProxyInstance( Thread.currentThread().getContextClassLoader(), new Class<?>[] { Visitable.class }, new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { return method.invoke(visitable, args); } }); proxyVisitable.accept(new Visitor() { @Override public void visit(Visitable visitorHost) { System.out.println(visitorHost.getClass()); } }); } } This makes a ConcreteVisitable which inherits the accept method from AbstractVisitable. In c++, I would consider this risky, since this in AbstractVisitable could be referencing to AbstractVisitable::this, and not ConcreteVisitable::this. I was worried that the code under certain circumstances would print class AbstractVisible. Yet the code above outputs class ConcreteVisitable, even though I hid the real type behind a dynamic proxy (the most difficult case I could come up with). Is the abstract visitor approach above guaranteed to work, or are there some pitfalls with this approach? What guarantees are given in Java with respect to the this pointer?

    Read the article

  • Need help with android.os.Build.VERSION.SDK_INT and SharedPreferences

    - by Fenderf4i
    I have a main activity where I call VersionSettings vs = new VersionSettings(this); if (vs.firstRun2()) vs.versionCheckbox(); What I'm trying to do is set a checkbox (checkboxVideoType) to an unchecked state if the Android version is 1.6-2.1 I only want to do this the very first time the app is ever run, it never needs to run again. I think I'm running into the problem when the main activity calls versionCheckbox(), I get a force close if it attempts to run the code inside that is going to set the checkbox to false. I'm very new to programming and would really appreciate some help with this. I think I'm close, but need a push. Thanks in advance! Main Activity import android.app.Activity; import android.content.Intent; import android.content.SharedPreferences; import android.net.Uri; import android.os.Bundle; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.widget.Button; import android.widget.ImageView; public class Nasatv extends Activity implements OnClickListener { boolean checkboxIsChecked; SharedPreferences nasaTV_Prefs; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_CUSTOM_TITLE); setContentView(R.layout.main); getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.window_title); nasaTV_Prefs = getSharedPreferences("nasaTV_Prefs", 0); ChangeLog cl = new ChangeLog(this); if (cl.firstRun()) cl.getLogDialog().show(); VersionSettings vs = new VersionSettings(this); if (vs.firstRun2()) vs.versionCheckbox(); Button button = (Button) findViewById(R.id.button1); button.setOnClickListener(this); Button button2 = (Button) findViewById(R.id.button2); button2.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent i = new Intent(Nasatv.this, LaunchCalendar.class); startActivity(i); } }); Button button3 = (Button) findViewById(R.id.button3); button3.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent i = new Intent(Nasatv.this, PhotoInfo.class); startActivity(i); } }); CheckConnectivity check = new CheckConnectivity(); Boolean conn = check.checkNow(this.getApplicationContext()); if(conn == true){ ImageView updateImage = (ImageView) findViewById(R.id.updateImage); ImageDownloader downloader = new ImageDownloader(updateImage); downloader.execute("http://www.url.com/trl/ubox.jpg"); } else { ImageView updateImage = (ImageView) findViewById(R.id.updateImage); updateImage.setImageResource(R.drawable.uboxerror); } } public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.options_menu, menu); return true; } public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.setting_title: Intent settingsActivity =new Intent(getBaseContext(), Settings.class); startActivity(settingsActivity); return true; case R.id.photo_archive: Intent archive = new Intent(Nasatv.this, PhotoArchive.class); startActivity(archive); return true; case R.id.n_web: Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.nasa.gov/")); startActivity(intent); return true; case R.id.exit_title: finish(); return true; default: return super.onOptionsItemSelected(item); } } public void onResume() { super.onResume(); checkboxIsChecked = nasaTV_Prefs.getBoolean("checkboxVideoType", true); } @Override public void onClick(View v) { if (checkboxIsChecked) { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.nasa.gov/multimedia/nasatv/nasatv_android_flash.html")); startActivity(intent); } else { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("rtsp://nasadln.qt.llnwd.net/nasa101.sdp")); startActivity(intent); } } } One-time run class import android.content.Context; import android.content.SharedPreferences; import android.preference.PreferenceManager; import android.util.Log; import android.widget.CheckBox; public class VersionSettings { private final Context context; private String notRun, hasRun; private SharedPreferences run; private CheckBox checkboxVideoType; private SharedPreferences nasaTV_Prefs; private static final String HAS_RUN = "PREFS_HAS_RUN"; int currentapiVersion = android.os.Build.VERSION.SDK_INT; /** * Constructor * * Retrieves whether the app has been run or not and saves to * SharedPreferences */ public VersionSettings(Context context) { this.context = context; this.run = PreferenceManager.getDefaultSharedPreferences(context); // get run/not run string number, which is "1" this.notRun = run.getString(HAS_RUN, ""); Log.d(TAG, "notRun: " + notRun); this.hasRun = context.getResources().getString(R.string.has_run_string); Log.d(TAG, "hasRun: " + hasRun); // save new number to preferences, which will be the same number, // so this is run only the very first time the app is run SharedPreferences.Editor editor = run.edit(); editor.putString(HAS_RUN, hasRun); editor.commit(); } /** * @return true if this version of your app is started for the first * time */ public boolean firstRun2() { return ! notRun.equals(hasRun); } /** * @return Change the checkboxVideoType to "unchecked" (false) * */ public void versionCheckbox() { // this.context = context; if (currentapiVersion < android.os.Build.VERSION_CODES.FROYO){ this.nasaTV_Prefs = PreferenceManager.getDefaultSharedPreferences(context); SharedPreferences.Editor editor = nasaTV_Prefs.edit(); editor.putBoolean("checkboxVideoType", false); editor.commit(); } } private static final String TAG = "VersionSettings"; } Preferences Activity import android.app.Activity; import android.content.SharedPreferences; import android.os.Bundle; import android.view.View; import android.view.Window; import android.widget.Button; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.CompoundButton.OnCheckedChangeListener; public class Settings extends Activity implements OnCheckedChangeListener { private CheckBox checkboxVideoType; private SharedPreferences nasaTV_Prefs; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_CUSTOM_TITLE); setContentView(R.layout.preferences); getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.window_title); checkboxVideoType = (CheckBox) findViewById(R.id.checkboxVideoType); checkboxVideoType.setOnCheckedChangeListener(this); nasaTV_Prefs = getSharedPreferences("nasaTV_Prefs", 0); checkboxVideoType.setChecked(nasaTV_Prefs.getBoolean("checkboxVideoType", true)); Button clbutton = (Button) findViewById(R.id.clbutton); clbutton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { ChangeLog cl = new ChangeLog(Settings.this); cl.getFullLogDialog().show(); } }); } public void onCheckedChanged(CompoundButton cb, boolean isChecked) { if (cb == checkboxVideoType){ SharedPreferences.Editor editor = nasaTV_Prefs.edit(); editor.putBoolean("checkboxVideoType", isChecked); editor.commit(); // Commit the edit, i.e., save the state of the flag! } } }

    Read the article

  • C# parameter count mismatch when trying to add AsyncCallback into BeginInvoke()

    - by PunX
    I have main form (PrenosForm) and I am trying to run Form2 asynchronously. It works without callback delegate: this.BeginInvoke(cp, new object[] { datoteke, this.treeView1.SelectedNode.FullPath.ToString(), this, efekt }, null); //works 1. Doesn't work with callback delegate (parameter count mismatch): this.BeginInvoke(cp, new object[] { datoteke, this.treeView1.SelectedNode.FullPath.ToString(), this, efekt }, new AsyncCallback(callBackDelegate), null); //doesn't work parameter count mismatch 2. Works with callback delegate if I do it like this: cp.BeginInvoke(datoteke, this.treeView1.SelectedNode.FullPath.ToString(), this, efekt, new AsyncCallback(callBackDelegate), null); //works 3. My question is why does one way work and the other doesn't? I'm new at this. Would anyone be so kind as to answer my question and point out my mistakes? private delegate void copyDelegat(List<ListViewItem> datoteke, string path, PrenosForm forma, DragDropEffects efekt); private delegate void callBackDelegat(IAsyncResult a); public void doCopy(List<ListViewItem> datoteke, string path, PrenosForm forma, DragDropEffects efekt) { new Form2(datoteke, path, forma, efekt); } public void callBackFunc(IAsyncResult a) { AsyncResult res = a.AsyncState as AsyncResult; copyDelegat delegat = res.AsyncDelegate as copyDelegat; delegat.EndInvoke(a); } public void kopiraj(List<ListViewItem> datoteke, DragDropEffects efekt) { copyDelegat cp = new copyDelegat(doCopy); callBackDelegat callBackDelegate = new callBackDelegat(callBackFunc); this.BeginInvoke(cp, new object[] { datoteke, this.treeView1.SelectedNode.FullPath.ToString(), this, efekt }, new AsyncCallback(callBackDelegate), null); //doesn't work parameter count missmatch 2. this.BeginInvoke(cp, new object[] { datoteke, this.treeView1.SelectedNode.FullPath.ToString(), this, efekt }, null); //works 1. cp.BeginInvoke(datoteke, this.treeView1.SelectedNode.FullPath.ToString(), this, efekt, new AsyncCallback(callBackDelegate), null); //works 3. }

    Read the article

  • Programmatically changing code files

    - by Carra
    I'm changing our webservices to an async model. And for that I have to change over a hundred methods. Doing it manually is one (unappealing) option. Is there no way to programmatically parse & change multiple functions/code files? Example: [Webmethod] public void MyWebservice (string parameter1, string parameter2, string parameter3) { //Logic here } And change this to: public void InternalMyWebservice (string parameter1, string parameter2, string parameter3, AsyncCallback callback) { //Logic here } [Webmethod] public void BeginMyWebservice (string parameter1, string parameter2, string parameter3, AsyncCallback callback, object asyncState) { //Queue InternalMyWebservice in a threadpool } public void EndMyWebservice(IAsyncResult asyncResult) { //Set return values } It's basically the same thing I have to do for each webservice. Change the name to "InternalX", add a parameter and create the begin & end method.

    Read the article

  • virtual function call from base class

    - by Gal Goldman
    Say we have: Class Base { virtual void f(){g();}; virtual void g(){//Do some Base related code;} }; Class Derived : public Base { virtual void f(){Base::f();}; virtual void g(){//Do some Derived related code}; }; int main() { Base *pBase = new Derived; pBase-f(); return 0; } Which g() will be called from Base::f()? Base::g() or Derived::g()? Thanks...

    Read the article

  • Avoid warning 'Unreferenced Formal Parameter'

    - by bdhar
    I have a super class like this: class Parent { public: virtual void Function(int param); }; void Parent::Function(int param) { std::cout << param << std::endl; } ..and a sub-class like this: class Child : public Parent { public: void Function(int param); }; void Child::Function(int param) { ;//Do nothing } When I compile the sub-class .cpp file, I get this error warning C4100: 'param' : unreferenced formal parameter As a practise, we used to treat warnings as errors. How to avoid the above warning? Thanks.

    Read the article

  • Qthread - trouble shutting down threads

    - by Bryan Greenway
    For the last few days, I've been trying out the new preferred approach for using QThreads without subclassing QThread. The trouble I'm having is when I try to shutdown a set of threads that I created. I regularly get a "Destroyed while thread is still running" message (if I'm running in Debug mode, I also get a Segmentation Fault dialog). My code is very simple, and I've tried to follow the examples that I've been able to find on the internet. My basic setup is as follows: I've a simple class that I want to run in a separate thread; in fact, I want to run 5 instances of this class, each in a separate thread. I have a simple dialog with a button to start each thread, and a button to stop each thread (10 buttons). When I click one of the "start" buttons, a new instance of the test class is created, a new QThread is created, a movetothread is called to get the test class object to the thread...also, since I have a couple of other members in the test class that need to move to the thread, I call movetothread a few additional times with these other items. Note that one of these items is a QUdpSocket, and although this may not make sense, I wanted to make sure that sockets could be moved to a separate thread in this fashion...I haven't tested the use of the socket in the thread at this point. Starting of the threads all seem to work fine. When I use the linux top command to see if the threads are created and running, they show up as expected. The problem occurs when I begin stopping the threads. I randomly (or it appears to be random) get the error described above. Class that is to run in separate thread: // Declaration class TestClass : public QObject { Q_OBJECT public: explicit TestClass(QObject *parent = 0); QTimer m_workTimer; QUdpSocket m_socket; Q_SIGNALS: void finished(); public Q_SLOTS: void start(); void stop(); void doWork(); }; // Implementation TestClass::TestClass(QObject *parent) : QObject(parent) { } void TestClass::start() { connect(&m_workTimer, SIGNAL(timeout()),this,SLOT(doWork())); m_workTimer.start(50); } void TestClass::stop() { m_workTimer.stop(); emit finished(); } void TestClass::doWork() { int j; for(int i = 0; i<10000; i++) { j = i; } } Inside my main app, code called to start the first thread (similar code exists for each of the other threads): mp_thread1 = new QThread(); mp_testClass1 = new TestClass(); mp_testClass1->moveToThread(mp_thread1); mp_testClass1->m_socket.moveToThread(mp_thread1); mp_testClass1->m_workTimer.moveToThread(mp_thread1); connect(mp_thread1, SIGNAL(started()), mp_testClass1, SLOT(start())); connect(mp_testClass1, SIGNAL(finished()), mp_thread1, SLOT(quit())); connect(mp_testClass1, SIGNAL(finished()), mp_testClass1, SLOT(deleteLater())); connect(mp_testClass1, SIGNAL(finished()), mp_thread1, SLOT(deleteLater())); connect(this,SIGNAL(stop1()),mp_testClass1,SLOT(stop())); mp_thread1->start(); Also inside my main app, this code is called when a stop button is clicked for a specific thread (in this case thread 1): emit stop1(); Sometimes it appears that threads are stopped and destroyed without issue. Other times, I get the error described above. Any guidance would be greatly appreciated. Thanks, Bryan

    Read the article

  • Why is this simple Mobile Form not closed when using the player

    - by ajhvdb
    Hi, I created this simple sample Form with the close button. Everything is working as expected when NOT using the Interop.WMPLib.dll I've seen other applications using this without problems but why isn't the Form process closed when I just add the line: SoundPlayer myPlayer = new SoundPlayer(); and of course dispose it: if (myPlayer != null) { myPlayer.Dispose(); myPlayer = null; } The Form closes but the debugger VS2008 is still active. The Form project and the dll are still active. If you send me an email to [email protected], I can send you the zipped project. Below is the class for the dll: using System; using System.Collections.Generic; using System.Text; using System.Threading; using System.Runtime.InteropServices; using WMPLib; namespace WindowsMobile.Utilities { public delegate void SoundPlayerStateChanged(SoundPlayer sender, SoundPlayerState newState); public enum SoundPlayerState { Stopped, Playing, Paused, } public class SoundPlayer : IDisposable { [DllImport("coredll")] public extern static int waveOutSetVolume(int hwo, uint dwVolume); [DllImport("coredll")] public extern static int waveOutGetVolume(int hwo, out uint dwVolume); WindowsMediaPlayer myPlayer = new WindowsMediaPlayer(); public SoundPlayer() { myPlayer.uiMode = "invisible"; myPlayer.settings.volume = 100; } string mySoundLocation = string.Empty; public string SoundLocation { get { return mySoundLocation; } set { mySoundLocation = value; } } public void Pause() { myPlayer.controls.pause(); } public void PlayLooping() { Stop(); myPlayer.URL = mySoundLocation; myPlayer.settings.setMode("loop", true); } public int Volume { get { return myPlayer.settings.volume; } set { myPlayer.settings.volume = value; } } public void Play() { Stop(); myPlayer.URL = mySoundLocation; myPlayer.controls.play(); } public void Stop() { myPlayer.controls.stop(); myPlayer.close(); } #region IDisposable Members public void Dispose() { try { Stop(); } catch (Exception) { } // need this otherwise the process won't exit?! try { int ret = Marshal.FinalReleaseComObject(myPlayer); } catch (Exception) { } myPlayer = null; GC.Collect(); } #endregion } }

    Read the article

< Previous Page | 61 62 63 64 65 66 67 68 69 70 71 72  | Next Page >