Search Results

Search found 46494 results on 1860 pages for 'public key encryption'.

Page 468/1860 | < Previous Page | 464 465 466 467 468 469 470 471 472 473 474 475  | Next Page >

  • non-static method setPrzechowaj(java.lang.String) cannot be referenced froma a static context

    - by bigbluedragon
    hey i have problem with JDialogForm. I have created it using netbeans 6.8. That JDialogForm have textfield and button below it. and here is some code... private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { String sciezka = jTextField1.getText(); if (sciezka.length() > 0) { Zmienne_pomocnicze.setPrzechowaj(sciezka); } } Now i want to copy that string "sciezka" to my main window but if I do it like this public class Zmienne_pomocnicze { public String n; public void setPrzechowaj (String neew) { n = neew; } public String getPrzechowaj () { return n; } } i get error in jButton1: non-static method setPrzechowaj(java.lang.String) cannot be referenced froma a static context any ideas?

    Read the article

  • .NET immutable object usage best practices? Should I be using them as much as possible?

    - by Daniel
    Say I have a simple object such as class Something { public int SomeInt { get; set; } } I have read that using immutable objects are faster and a better means of using business objects? If this is so, should i strive to make all my objects as such: class ImmutableSomething { public int SomeInt { get { return m_someInt; } } private int m_someInt = 0; public void ChangeSomeInt(int newValue) { m_someInt = newvalue; } } What do you reckon?

    Read the article

  • Passing ViewModel for backbone.js from MVC3 Server-Side

    - by Roman
    In ASP.NET MVC there is Model, View and Controller. MODEL represents entities which are stored in database and essentially is all the data used in a application (for example, generated by EntityFramework, "DB First" approach). Not all data from model you want to show in the view (for example, hashs of passwords). So you create VIEW MODEL, each for every strongly-typed-razor-view you have in application. Like this: using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace MyProject.ViewModels.SomeController.SomeAction { public class ViewModel { public ViewModel() { Entities1 = new List<ViewEntity1>(); Entities2 = new List<ViewEntity2>(); } public List<ViewEntity1> Entities1 { get; set; } public List<ViewEntity2> Entities2 { get; set; } } public class ViewEntity1 { //some properties from original DB-entity you want to show } public class ViewEntity2 { } } When you create complex client-side interfaces (I do), you use some pattern for javascript on client, MVC or MVVM (I know only these). So, with MVC on client you have another model (Backbone.Model for example), which is third model in application. It is a bit much. Why don`t we use the same ViewModel model on a client (in backbone.js or another framework)? Is there a way to transfer CS-coded model to JS-coded? Like in MVVM pattern, with knockout.js, when you can do like this: in SomeAction.cshtml: <div style="display: none;" id="view_model">@Json.Encode(Model)</div> after that in Javascript-code var ViewModel = ko.mapping.fromJSON($("#view_model").get(0).innerHTML); now you can extend your ViewModel with some actions, event handlers, etc: ko.utils.extend(ViewModel, { some_function: function () { //some code } }); So, we are not building the same view model on the client again, we are transferring existing view model from server. At least, data. But knockout.js is not suitable for me, you can`t build complex UI with it, it is just data-binding. I need something more structural, like backbone.js. The only way to build ViewModel for backbone.js I can see now is re-writing same ViewModel in JS from server with hands. Is there any ways to transfer it from server? To reuse the same viewmodel on server view and client view?

    Read the article

  • Avoiding repeated subqueries when 'WITH' is unavailable

    - by EloquentGeek
    MySQL v5.0.58. Tables, with foreign key constraints etc and other non-relevant details omitted for brevity: CREATE TABLE `fixture` ( `id` int(11) NOT NULL auto_increment, `competition_id` int(11) NOT NULL, `name` varchar(50) NOT NULL, `scheduled` datetime default NULL, `played` datetime default NULL, PRIMARY KEY (`id`) ); CREATE TABLE `result` ( `id` int(11) NOT NULL auto_increment, `fixture_id` int(11) NOT NULL, `team_id` int(11) NOT NULL, `score` int(11) NOT NULL, `place` int(11) NOT NULL, PRIMARY KEY (`id`) ); CREATE TABLE `team` ( `id` int(11) NOT NULL auto_increment, `name` varchar(50) NOT NULL, PRIMARY KEY (`id`) ); Where: A draw will set result.place to 0 result.place will otherwise contain an integer representing first place, second place, and so on The task is to return a string describing the most recently played result in a given competition for a given team. The format should be "def Team X,Team Y" if the given team was victorious, "lost to Team X" if the given team lost, and "drew with Team X" if there was a draw. And yes, in theory there could be more than two teams per fixture (though 1 v 1 will be the most common case). This works, but feels really inefficient: SELECT CONCAT( (SELECT CASE `result`.`place` WHEN 0 THEN "drew with" WHEN 1 THEN "def" ELSE "lost to" END FROM `result` WHERE `result`.`fixture_id` = (SELECT `fixture`.`id` FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` WHERE `fixture`.`competition_id` = 2 AND `result`.`team_id` = 1 ORDER BY `fixture`.`played` DESC LIMIT 1) AND `result`.`team_id` = 1), ' ', (SELECT GROUP_CONCAT(`team`.`name`) FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` LEFT JOIN `team` ON `result`.`team_id` = `team`.`id` WHERE `fixture`.`id` = (SELECT `fixture`.`id` FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` WHERE `fixture`.`competition_id` = 2 AND `result`.`team_id` = 1 ORDER BY `fixture`.`played` DESC LIMIT 1) AND `team`.`id` != 1) ) Have I missed something really obvious, or should I simply not try to do this in one query? Or does the current difficulty reflect a poor table design?

    Read the article

  • Need help in creating test application in Java and passing parameters into a new designed Java API.

    - by Christophe
    Need help, Please!!! By following the protocol, the Request should be built in 5 byte length, including 1 byte for changing Braud rate (Speed), and send request to a RS-232 port. Protocol: Request for the command processing, with optional extra byte for changing Baud Rate: LGT : length message ( LGT = 5 ) TYPE : 0x06 TO(time out): 0x0000 CMD : (1 byte) 0x02 application update Baud Rate : (1 byte) 0xNN (optional parameter to change baud rate of the Mnt App) where NN can be: 0x00 = No Baud Rate Change (similar to 4-byte command above) 0x09 = Change to 9600 Baud for Application Update speed 0x0A = Change to 19200 Baud for Application Update speed 0x0E = Change to 115200 Baud for Application Update speed All other bytes are not accepted and will result in a status of 0x01. I'm trying to test if my code works or not by creating another class (TestApplication.java) and pass the "3 differenr Baut rate" to this CPXAppliaction. the 3 Baud Rate is supposed to input by reading a file.txt. Question: How do you think these code (first half)? please don't warry about the details about the "sending part". I mean, do I need setter/getter for the "speed" parameter pass? I created the demo test class DemoApp.java (input speed by reading a txt file, and pass into CPXAppliaction). how do you think about that code? Many thanks to you guys!! public class CPXApplication extends CPXCommand { private int speed; . public CPXApplication() { speed = 9600; } public CPXApplication(int speedinit) { speed = speedinit; // TODO: where to get the speed? } protected void buildRequest() throws ElitePortException { String trans = ""; // build the full-qualified message following the protocol trans = addToRequest(trans, (char) 0); trans = addToRequest(trans, (char) 5); trans = addToRequest(trans, (char) 6); trans = addToRequest(trans, (char) 0); trans = addToRequest(trans, (char) 0); trans = addToRequest(trans, (char) 2); switch (speed) { case 9600: trans = addToRequest(trans, (char) 0x09); break; case 19200: trans = addToRequest(trans, (char) 0x0A); break; case 115200: trans = addToRequest(trans, (char) 0x0E); break; default: // TODO: unexpected baud rate. throw(); break; } trans = EncryptBinary(trans); trans = "F0." + trans; wrapRequest(trans); } protected String addToRequest(String req, char c) { return req + c; } protected String addToRequest(String req, String s) { return req + s; } protected String addToRequest(String req) { return req; } public void analyzeResponse() { //.............. } } Here is the demo test code: class Run { public static void run() { CPXAppliaction input = new CpXApplication(); int lineno = 0; try { FileReader fr = new FileReader("baudRateSpeed.txt"); BufferedReader reader = new BufferedReader(fr); String line = reader.readLine(); Scanner scan = null; while (line != null) { scan = new Scanner(line); String speed; speed = scan.next(); if (lineno == 0) { input.speed = speed; lineno++; } else { input = cpxapplication(speed, input); } line = reader.readLine(); } reader.close(); } catch (FileNotFoundException e) { System.out.println("Could not find the file"); } catch (IOException e) { System.out.println("Had a problem reading from file"); } } } public class DemoApp{ public void main(String args[]) { run(); }

    Read the article

  • php while selecting a node should be highlighted.

    - by shaibi
    I need to highlight the node value when I select it.how can I wrirte code for that in php my code is function generate_menu($parent) { $has_childs = false; global $menu_array; foreach($menu_array as $key = $value) { //print_r($value); if ($value['parentid'] == $parent) { if ($has_childs === false) { $has_childs = true; $menu .= '<ul>'; } $clor = 'black'; if(($_GET['id']>0) &&($key == $_GET['id'])) { $clor = '#990000'; } $chld = generate_menu($key); $cls = ($chld != '')? 'folder' : 'file'; $menu .= '<li><span class="'.$cls.'" color='.$clor.'>&nbsp;' . $value['humanid'].'-'.$value['title'] . ' <a href="index.php?id='.$key.'"><img src="images/edit.png" alt=" Edit" title="Edit"/></a></span>'; $menu .= $chld; $menu .= '</li>'; } } if ($has_childs === true) $menu .= '</ul>'; return $menu ; } ?

    Read the article

  • Beginner Ques::How to delete records permanently in case of linked tables?

    - by Serenity
    Let's say I have these 2 tables QuesType and Ques:- QuesType QuestypeID|QuesType |Active ------------------------------------ 101 |QuesType1 |True 102 |QuesType2 |True 103 |XXInActiveXX |False Ques QuesID|Ques|Answer|QUesTypeID|Active ------------------------------------ 1 |Ques1|Ans1 |101 |True 2 |Ques2|Ans2 |102 |True 3 |Ques3|Ans3 |101 |True In the QuesType Table:- QuesTypeID is a Primary key In the Ques Table:- QuesID is a Primary key and QuesType ID is the Foreign Key that refernces QuesTypeID from QuesType Table Now I am unable to delete records from QuesType Table, I can only make QuesType inactive by setting Active=False. I am unable to delete QuesTypes permanently because of the Foreign key relation it has with Ques Table. So , I just set the column Active=false and those Questypes then don't show on my grid wen its binded. What I want to do is be able to delete any QuesType permamnently. Now it can only be deleted if its not being used anywhere in the Ques table, right? So to delete any QuesType permanently I thot this is what I could do:- In the grid that displays QuesTypes, I have this check box for Active and a button for delete.What I thot was, when a user makes some QuesType inactive then OnCheckChanged() event will run and that will have the code to delete all the Questions in Ques table that are using that QuesTypeID. Then on the QuesType grid, that QuesType would show as Deactivated and only then can a user delete it permanently. Am I thinking correctly? Currently in my DeleteQuesType Stored Procedure what I am doing is:- Setting the Active=false and Setting QuesTye= some string like XXInactiveXX Is there any other way?

    Read the article

  • What's the best way to implement a dynamic proxy in C#?

    - by gap
    Hi, I've got a need to create a dynamic proxy in C#. I want this class to wrap another class, and take on it's public interface, forwarding calls for those functions: class MyRootClass { public virtual void Foo() { Console.Out.WriteLine("Foo!"); } } interface ISecondaryInterface { void Bar(); } class Wrapper<T> : ISecondaryInterface where T: MyRootClass { public Wrapper(T otherObj) { } public void Bar() { Console.Out.WriteLine("Bar!"); } } Here's how I want to use it: Wrapper<MyRootClass> wrappedObj = new Wrapper<MyRootClass>(new MyRootClass()); wrappedObj.Bar(); wrappedObj.Foo(); to produce: Bar! Foo! Any ideas? What's the easiest way to do this? What's the best way to do this? Thanks so much.

    Read the article

  • How to increment the string value during run time without using dr.read() and store it in the oledb

    - by sameer
    Here is my code, everything is working fine the only problem is with the ReadData() method in which i want the string value to be increment i.e AM0001,AM0002,AM0003 etc. This is happening but only one time the value is getting increment to AM0001, the second time the same value i.e AM0001 is getting return. Due to this i am getting a error from oledb because of AM0001 is a primary key field. enter code here: class Jewellery : Connectionstr { string lmcode = null; public string LM_code { get { return lmcode;} set { lmcode = ReadData();} } string mname; public string M_Name { get { return mname; } set { mname = value;} } string desc; public string Desc { get { return desc; } set { desc = value; } } public string ReadData() { string jid = string.Empty; string displayString = string.Empty; String query = "select max(LM_code)from Master_Accounts"; Datamanager.RunExecuteReader(Constr,query); if (string.IsNullOrEmpty(jid)) { jid = "AM0000";//This string value has to increment at every time, but it is getting increment only one time. } int len = jid.Length; string split = jid.Substring(2, len - 2); int num = Convert.ToInt32(split); num++; displayString = jid.Substring(0, 2) + num.ToString("0000"); return displayString; } public void add() { String query ="insert into Master_Accounts values ('" + LM_code + "','" + M_Name + "','" + Desc + "')"; Datamanager.RunExecuteNonQuery(Constr , query); } Any help will be appreciated.

    Read the article

  • When mocking a class with Moq, how can I CallBase for just specific methods?

    - by Daryn
    I really appreciate Moq's Loose mocking behaviour that returns default values when no expectations are set. It's convenient and saves me code, and it also acts as a safety measure: dependencies won't get unintentionally called during the unit test (as long as they are virtual). However, I'm confused about how to keep these benefits when the method under test happens to be virtual. In this case I do want to call the real code for that one method, while still having the rest of the class loosely mocked. All I have found in my searching is that I could set mock.CallBase = true to ensure that the method gets called. However, that affects the whole class. I don't want to do that because it puts me in a dilemma about all the other properties and methods in the class that hide call dependencies: if CallBase is true then I have to either Setup stubs for all of the properties and methods that hide dependencies -- Even though my test doesn't think it needs to care about those dependencies, or Hope that I don't forget to Setup any stubs (and that no new dependencies get added to the code in the future) -- Risk unit tests hitting a real dependency. Q: With Moq, is there any way to test a virtual method, when I mocked the class to stub just a few dependencies? I.e. Without resorting to CallBase=true and having to stub all of the dependencies? Example code to illustrate (uses MSTest, InternalsVisibleTo DynamicProxyGenAssembly2) In the following example, TestNonVirtualMethod passes, but TestVirtualMethod fails - returns null. public class Foo { public string NonVirtualMethod() { return GetDependencyA(); } public virtual string VirtualMethod() { return GetDependencyA();} internal virtual string GetDependencyA() { return "! Hit REAL Dependency A !"; } // [... Possibly many other dependencies ...] internal virtual string GetDependencyN() { return "! Hit REAL Dependency N !"; } } [TestClass] public class UnitTest1 { [TestMethod] public void TestNonVirtualMethod() { var mockFoo = new Mock<Foo>(); mockFoo.Setup(m => m.GetDependencyA()).Returns(expectedResultString); string result = mockFoo.Object.NonVirtualMethod(); Assert.AreEqual(expectedResultString, result); } [TestMethod] public void TestVirtualMethod() // Fails { var mockFoo = new Mock<Foo>(); mockFoo.Setup(m => m.GetDependencyA()).Returns(expectedResultString); // (I don't want to setup GetDependencyB ... GetDependencyN here) string result = mockFoo.Object.VirtualMethod(); Assert.AreEqual(expectedResultString, result); } string expectedResultString = "Hit mock dependency A - OK"; }

    Read the article

  • What is the explanation of this results in Java ?

    - by M.H
    I have the following code : public class Main { private int i = j; //1 private int j = 10; public static void main(String[] args) { System.out.println((new Main()).i); } } and there is a compiler error in line 1 because an illegal forward reference. But when I am trying the following code : public class Main { int i = getJ(); //1 int getJ(){ return j; } int j=10; public static void main(String[] args) { System.out.println(new Main().i); } } it works fine and the result is 0.Why there is no illegal forward reference in line 1 here?.The two codes look similar to me.

    Read the article

  • Find the class of the generic object

    - by Mgccl
    Suppose I have the following class. public class gen<T> { public gen(){ } Class<T> class(){ //something that figures out what T is. } } How can I implement the class() function without pass any additional information? What I did is here, but I have to pass a object of T into the object gen. public class gen<T> { public gen(){ } Class<T> class(T var){ return (Class<T>) var.getClass(); } }

    Read the article

  • Using enums in Java across multiple classes

    - by Richard Mar.
    I have the following class: public class Card { public enum Suit { SPACES, HEARTS, DIAMONDS, CLUBS }; public Card(Suit nsuit, int nrank) { suit = nsuit; rank = nrank; } private Suit suit; private int rank; } I want to instantiate it in another class, but that class doesn't understand the Suit enum. Where should I put the enum to make it publicly visible?

    Read the article

  • Accessing a function of an instance which is in an arraylist

    - by fadeir
    I'm tring to access a function of an instance which is in an arraylist. Is there any way to do that without using the class name of the instance? import java.util.ArrayList; import java.util.List; class apple{ int price; public void myFunction(int iPrice) { price=iPrice; } } class orange{ int price; public void myFunction(int iPrice) { price=iPrice; } } public class main { public static void main(String[] args) { List list= new ArrayList(); //create 3 apple object to list list.add( new apple() ); list.add( new apple() ); list.add( new orange() ); list.get(0).myFunction(1); /* Error: The method myFunction(int) is undefined for the type Object*/ } } I know that;((apple) list.get(0)).myFunction(1); is a way but I'dont want to use any class name while calling the function.

    Read the article

  • Unlock device, display a text, then lock again

    - by Waza_Be
    For the need of my application, I need to display a message on the screen even if the lockscreen is enabled, then wait 3 seconds, than I have to lock again the phone as I don't want it to make unwanted phone calls in your pockets. First part is easy: if (PreferenceManager.getDefaultSharedPreferences( getBaseContext()).getBoolean("wake", false)) { KeyguardManager kgm = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE); boolean isKeyguardUp = kgm.inKeyguardRestrictedInputMode(); WakeLocker.acquire(ProtoBenService.this); Intent myIntent = new Intent(ProtoBenService.this,LockActivity.class); myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); if (isKeyguardUp) { ProtoBenService.this.startActivity(myIntent); } else Toast.makeText(ProtoBenService.this.getBaseContext(), intention, Toast.LENGTH_LONG).show(); WakeLocker.release(); } With this class: public abstract class WakeLocker { private static PowerManager.WakeLock wakeLock; public static void acquire(Context ctx) { if (wakeLock != null) wakeLock.release(); PowerManager pm = (PowerManager) ctx.getSystemService(Context.POWER_SERVICE); wakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP | PowerManager.ON_AFTER_RELEASE, "CobeIm"); wakeLock.acquire(); } public static void release() { if (wakeLock != null) wakeLock.release(); wakeLock = null; } } And the Activity: public class LockActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Window window = getWindow(); window.addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD); window.addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON); window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); TextView tv = new TextView(this); tv.setText("This is working!"); tv.setTextSize(45); setContentView(tv); Runnable mRunnable; Handler mHandler = new Handler(); mRunnable = new Runnable() { @Override public void run() { LockActivity.this.finish(); } }; mHandler.postDelayed(mRunnable, 3 * 1000); } } So, this is nice, the phone can display my text! The only problem comes when I want to lock again the phone, it seems that locking the phone is protected by the system... Programmatically turning off the screen and locking the phone how to lock the android programatically I think that my users won't understand the Device Admin and won't be able to activate it. Is there any workaround to lock the screen without the Device Admin stuff?

    Read the article

  • A Surface view and a canvas to move Bitmap

    - by John Apple Sim
    I have a SurfaceView and I want the Bitmap Logo inside it in the canvas to be movable What I'm doing wrong ? static float x, y; Bitmap logo; SurfaceView ss = (SurfaceView) findViewById(R.id.svSS); logo = BitmapFactory.decodeResource(getResources(), R.drawable.logo); x = 40; y = 415; ss.setOnTouchListener(new View.OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent me) { try { Thread.sleep(50); } catch (InterruptedException e) { e.printStackTrace(); } switch(me.getAction()) { case MotionEvent.ACTION_DOWN: x = me.getX(); y = me.getY(); break; case MotionEvent.ACTION_UP: x = me.getX(); y = me.getY(); break; case MotionEvent.ACTION_MOVE: x = me.getX(); y = me.getY(); break; } return true; } }); public class OurView extends SurfaceView implements Runnable{ Thread t = null; SurfaceHolder holder; boolean isItOK = false; public OurView(Context context) { super(context); holder = getHolder(); } public void run (){ while (isItOK == true){ //canvas DRAWING if (!holder.getSurface().isValid()){ continue; } Canvas c = holder.lockCanvas(); c.drawARGB(255, 200, 100, 100); c.drawBitmap(logo, x,y,null); holder.unlockCanvasAndPost(c); } } public void pause(){ isItOK = false; while(true){ try { t.join(); } catch (InterruptedException e) { e.printStackTrace(); } break; } t = null; } public void resume(){ isItOK = true; t = new Thread(this); t.start(); } } Now the surface view is just black .. nothing happens also its not colored 200, 100, 100

    Read the article

  • Can I set a PHP class property from an existing variable?

    - by jasondavis
    I am trying to figure out how I want to handle settings in my PHP app. I have pretty much decide that I would like to use a Confg class file so it will be autoloaded and flexible in the future. Below is some stuff I was playing with. I know you cannot set a variable to popluate a Constant so I then try to use a public static property. Why can I not set public static $ip = $_SERVER['REMOTE_ADDR']; ?? <?php // config.class.php class Config { const URL = 'http://www.foo.com'; const DB_User = 'dbname'; public static $test = 'test string'; public static $ip = $_SERVER['REMOTE_ADDR']; } /////////////////////////////////////////////////////// //index.php // works echo Config::URL; // works echo Config::$test; // DOES NOT WORK echo Config::$ip; ?>

    Read the article

  • Qt, can't display child widget

    - by Blin
    I have two widgets defined as follows class mainWindow : public QWidget { Q_OBJECT public: mainWindow(); void readConfig(); private: SWindow *config; QVector <QString> filePath; QVector <QLabel*> alias,procStatus; QVector <int> delay; QGridLayout *mainLayout; QVector<QPushButton*> stopButton,restartButton; QVector<QProcess*> proc; QSignalMapper *stateSignalMapper, *stopSignalMapper, *restartSignalMapper; public slots: void openSettings(); void startRunning(); void statusChange(int); void stopProc(int); void restartProc(int); void renew(); }; class SWindow : public QWidget { Q_OBJECT public: SWindow(QWidget *parent=0); void readConfig(); void addLine(int); private: QVector<QPushButton*> selectButton; QVector<QLabel*> filePath; QVector<QLineEdit*> alias; QSignalMapper *selectSignalMapper; QVector<QSpinBox*> delay; QGridLayout *mainLayout; public slots: void selectFile(int); void saveFile(); void addLineSlot(); }; when i create and display SWindow object from mainWindow like this void mainWindow::openSettings() { config = new SWindow(); config->show(); } everything is ok, but now i need to access the mainWindow from SWindow, and void mainWindow::openSettings() { config = new SWindow(this); config->show(); } doesn't display SWindow. How can i display SWindow? How do i call a function on widget close?

    Read the article

  • How does object of sub-class record information about its super-class the in a Virtual Inheritance

    - by Summer_More_More_Tea
    Hi there: I encounter this problem when tackling with virtual inheritance. I remember that in a non-virtual inheritance hierarchy, object of sub-class hold an object of its direct super-class. What about virtual inheritance? In this situation, does object of sub-class hold an object of its super-class directly or just hold a pointer pointing to an object of its super-class? By the way, why the output of the following code is: sizeof(A): 8 sizeof(B): 20 sizeof(C): 32 Code: #include <iostream> using namespace std; class A{ char k[ 3 ]; public: virtual void a(){}; }; class B : public virtual A{ char j[ 3 ]; public: virtual void b(){}; }; class C : public virtual B{ char i[ 3 ]; public: virtual void c(){}; }; int main( int argc, char *argv[] ){ cout << "sizeof(A): " << sizeof( A ) << endl; cout << "sizeof(B): " << sizeof( B ) << endl; cout << "sizeof(C): " << sizeof( C ) << endl; return 0; } Thanks in advance. Kind regards.

    Read the article

  • About calling an subclass' overriding method when casted to its superclass

    - by Omega
    #include <iostream> class Vehicle { public: void greet() { std::cout << "Hello, I'm a vehicle"; } }; class Car : public Vehicle { public: void greet() { std::cout << "Hello, I'm a car"; } }; class Bike : public Vehicle { public: void greet() { std::cout << "Hello, I'm a bike"; } }; void receiveVehicle(Vehicle vehicle) { vehicle.greet(); } int main() { receiveVehicle(Car()); return 0; } As you can see, I'm trying to send a parameter of type Vehicle to a function, which calls greet(). Car and Bike are subclasses of Vehicle. They overwrite greet(). However, I'm getting "Hello, I'm a vehicle". I suppose that this is because receiveVehicle receives a parameter of type Vehicle instead of a specific subclass like Car or Bike. But that's what I want: I want this function to work with any subclass of Vehicle. Why am I not getting the expected output?

    Read the article

  • Timer in java ,time difference problem

    - by javatechi
    I want to create a timer for my app. The sample code is shown below. When the method datetwo() is called the same time in milliseconds is shown as there in the main method. Please help me out with this import java.util.Date; import java.util.Timer; public class TimerChe { Timer timer; static Date date = new Date(); static Date date2 = new Date(); public static void timerMethod(){ new Thread() { public void run() { try { while (true) { sleep(10000); datetwo(); } } catch (InterruptedException ex) { } } }.start(); } public static void datetwo() { System.out.println ("OK, It's time to do something!") ; System.out.println("The Time is " + date2.getTime() + " milliseconds since 1970/01/01"); } public static void main(String args[]) throws Exception { System.out.println("The Time is " + date.getTime() + " milliseconds since 1970/01/01" ); System.out.println ("Schedule something to do in the mean time.") ; timerMethod(); } }

    Read the article

  • how to query list in powershell

    - by Varyanica
    add-type -Language CSharpVersion3 -TypeDefinition @" public class pack_code { public pack_code() {} public string code { get; set; } public string type { get; set; } } "@ $a = New-Object pack_code $a.code = "3" $a.type = "5" $b = New-Object pack_code $b.code = "2" $b.type = "5" $c = New-Object pack_code $c.code = "2" $c.type = "5" $d = New-Object pack_code $d.code = "1" $d.type = "1" $codes = New-Object 'System.Collections.Generic.List[object]' $codes.add($a) $codes.add($b) $codes.add($c) $codes.add($d) is there a way to select distinct from $codes and select the objects where type equals 1? How can i use linq with PowerShell?

    Read the article

  • Is this linear search implementation actually useful?

    - by Helper Method
    In Matters Computational I found this interesting linear search implementation (it's actually my Java implementation ;-)): public static int linearSearch(int[] a, int key) { int high = a.length - 1; int tmp = a[high]; // put a sentinel at the end of the array a[high] = key; int i = 0; while (a[i] != key) { i++; } // restore original value a[high] = tmp; if (i == high && key != tmp) { return NOT_CONTAINED; } return i; } It basically uses a sentinel, which is the searched for value, so that you always find the value and don't have to check for array boundaries. The last element is stored in a temp variable, and then the sentinel is placed at the last position. When the value is found (remember, it is always found due to the sentinel), the original element is restored and the index is checked if it represents the last index and is unequal to the searched for value. If that's the case, -1 (NOT_CONTAINED) is returned, otherwise the index. While I found this implementation really clever, I wonder if it is actually useful. For small arrays, it seems to be always slower, and for large arrays it only seems to be faster when the value is not found. Any ideas?

    Read the article

  • runtime/compile time polymorphism

    - by dmadhavaraj
    Hi , In the below code , why b1.subtract() fails . Please explain me the reason ie., what happens in JVM while invoking that method . class Base { public void add() { System.out.println("Base ADD"); } } class Child extends Base { public void add(){ System.out.println("Child ADD"); } public void subtract() { System.out.println("Child Subtract"); } } class MainClass { public static void main(String args[]) { Base b1 = new Base(); Base b2 = new Child(); Child b3 = new Child(); b1.add(); b1.subtract(); // ?????????** b2.add(); b3.subtract(); } }

    Read the article

  • unresolved token/symbol in MC++ wrapper class calling native code

    - by rediVider
    I'm new to MC++ and have basically no idea what's going on yet. In trying to get this working i've determined many things that don't work, i'm just looking for one of the ways that will work. I have a mc++ class as follows that seems to have to be a "ref" class to allow me to see any methods/properties. public ref class EmCeePlusPlus { static void Open(void) { Testor* t = new Testor(); Testor::Open(); }; }; extern public class Testor { public: Testor() { }; static void Open(void) { int x = 3; int xx = cli_lock(x); }; }; Now, the only reason i created the class Testor, and moved the call to cli_open to it, is because i was getting a unresolved external symbol if i put the same call in the ref class. In this current code, however, I get an uresolved token error and unresolved symbol error ONLY if i have the call to Testor::Open(). If that line is commented then it compiles fine. As it is I get the errors below. cli_lock() is native code that is able to be called externally by other native DLLs with not problems. Any ideas where i should be looking? error LNK2028: unresolved token (0A000056) "extern "C" int __cdecl cli_lock(int)" (?cli_lock@@$$J0YAHH@Z) referenced in function "public: static void __cdecl Giga::Testor::Open(void)" (?Open@Testor@Giga@@$$FSAXXZ) error LNK2019: unresolved external symbol "extern "C" int __cdecl cli_lock(int)" (?cli_lock@@$$J0YAHH@Z) referenced in function "public: static void __cdecl Giga::Testor::Open(void)" (?Open@Testor@Giga@@$$FSAXXZ)

    Read the article

< Previous Page | 464 465 466 467 468 469 470 471 472 473 474 475  | Next Page >