Search Results

Search found 51282 results on 2052 pages for 'empty class'.

Page 113/2052 | < Previous Page | 109 110 111 112 113 114 115 116 117 118 119 120  | Next Page >

  • How to update GUI thread/class from worker thread/class?

    - by user315182
    First question here so hello everyone. The requirement I'm working on is a small test application that communicates with an external device over a serial port. The communication can take a long time, and the device can return all sorts of errors. The device is nicely abstracted in its own class that the GUI thread starts to run in its own thread and has the usual open/close/read data/write data basic functions. The GUI is also pretty simple - choose COM port, open, close, show data read or errors from device, allow modification and write back etc. The question is simply how to update the GUI from the device class? There are several distinct types of data the device deals with so I need a relatively generic bridge between the GUI form/thread class and the working device class/thread. In the GUI to device direction everything works fine with [Begin]Invoke calls for open/close/read/write etc. on various GUI generated events. I've read the thread here (How to update GUI from another thread in C#?) where the assumption is made that the GUI and worker thread are in the same class. Google searches throw up how to create a delegate or how to create the classic background worker but that's not at all what I need, although they may be part of the solution. So, is there a simple but generic structure that can be used? My level of C# is moderate and I've been programming all my working life, given a clue I'll figure it out (and post back)... Thanks in advance for any help.

    Read the article

  • Encapsulating user input of data for a class (C++)

    - by Dr. Monkey
    For an assignment I've made a simple C++ program that uses a superclass (Student) and two subclasses (CourseStudent and ResearchStudent) to store a list of students and print out their details, with different details shown for the two different types of students (using overriding of the display() method from Student). My question is about how the program collects input from the user of things like the student name, ID number, unit and fee information (for a course student) and research information (for research students): My implementation has the prompting for user input and the collecting of that input handled within the classes themselves. The reasoning behind this was that each class knows what kind of input it needs, so it makes sense to me to have it know how to ask for it (given an ostream through which to ask and an istream to collect the input from). My lecturer says that the prompting and input should all be handled in the main program, which seems to me somewhat messier, and would make it trickier to extend the program to handle different types of students. I am considering, as a compromise, to make a helper class that handles the prompting and collection of user input for each type of Student, which could then be called on by the main program. The advantage of this would be that the student classes don't have as much in them (so they're cleaner), but also they can be bundled with the helper classes if the input functionality is required. This also means more classes of Student could be added without having to make major changes to the main program, as long as helper classes are provided for these new classes. Also the helper class could be swapped for an alternative language version without having to make any changes to the class itself. What are the major advantages and disadvantages of the three different options for user input (fully encapsulated, helper class or in the main program)?

    Read the article

  • PDO using singleton stored as class properity

    - by Misiur
    Hi again. OOP drives me crazy. I can't move PDO to work. Here's my DB class: class DB extends PDO { public function &instance($dsn, $username = null, $password = null, $driver_options = array()) { static $instance = null; if($instance === null) { try { $instance = new self($dsn, $username, $password, $driver_options); } catch(PDOException $e) { throw new DBException($e->getMessage()); } } return $instance; } } It's okay when i do something like this: try { $db = new DB(DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS); } catch(DBException $e) { echo $e->getMessage(); } But this: try { $db = DB::instance(DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS); } catch(DBException $e) { echo $e->getMessage(); } Does nothing. I mean, even when I use wrong password/username, I don't get any exception. Second thing - I have class which is "heart" of my site: class Core { static private $instance; public $db; public function __construct() { if(!self::$instance) { $this->db = DB::instance(DB_TYPE.':hpost='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS); } return self::$instance; } private function __clone() { } } I've tried to use "new DB" inside class, but this: $r = $core->db->query("SELECT * FROM me_config"); print_r($r->fetch()); Return nothing. $sql = "SELECT * FROM me_config"; print_r($core->db->query($sql)); I get: PDOStatement Object ( [queryString] => SELECT * FROM me_config ) I'm really confused, what am I doing wrong?

    Read the article

  • Overriding the admin Media class

    - by shacker
    Given an admin media class that sets up a rich text editor, like: class TutorialAdmin(admin.ModelAdmin): fields... class Media: js = ['/paths/to/tinymce.js',] I would like the ability to selectively override js depending on a field value in the model it references. I've added a "use_editor" boolean to the Tutorial model. The question is, how can I detect whether the current instance has that bool set? I'd like to end up with something like: class Media: if self.use_editor: js = ['/path/to/tinymce.js',] else: js = '' Ideas? Thanks.

    Read the article

  • Tomcat JSP(2.0) Document how to stop automaticly closing empty body tags with /> instead of </tagnam

    - by JOKe
    The question is. If I use JSP Documents (or JSP 2.0) and If I put a TAG without a BODY it is automaticly closed I dont want that. so If I have <div id=....> </div> it is automaticly converted to <div id=.../> How I can stop this ? I am using tomcat is there any configuration about that ? P.S. the reason to want to stop it is because it simple "fuckes" the JQuery stuffs that the designer company are using.

    Read the article

  • creative way for implementing Data object with its corresponding business logic class in java

    - by ekeren
    I have a class that need to be serialized (for both persistentcy and client-server communication) for simplicity's sake let's call the classes Business a BusinessData and I prefix for their Interfaces. All the getter and setter are delegated from Business class to BusinessData class. I thought about implementing IBusinessData interface that will contain all the getter and setters and IBusiness interface that will extend it. I can either make Business extend BuisnessData so I will not need to implement all getter and setter delegates, or make some abstract class ForwardingBusinessData that will only delegate getter and setters. Any of the above option I lose my hierarchy freedom, do any of you have any creative solutions for this problem... I also reviewed DAO pattern: http://java.sun.com/blueprints/patterns/DAO.html

    Read the article

  • Python: Is there a way to reflectivly list all attributes of a class

    - by hhafez
    Given a class such as def MyClass text = "hello" number = 123 Is there a way in python to inspect MyClass an determine that it has the two attributes text and number. I can not use something like inspect.getSource(object) because the class I am to get it's attributes for are generate using SWIG (so they are hidden in .so :) ). So I am really looking for something equivalant to Java's [Class.getDeclardFields][1] Any help would be appreciated, otherwise I'll have to solve this problem with SWIG + JAVA instead of SWIG + Python.

    Read the article

  • executing a class in remote jvm

    - by redzedi
    Hi All, I have a small test class that i want to run on a particular jvm that's already up and running (basically it's an web application running on Tomcat) . The reason i want to do this is i want to execute a small test class (with the main method and all) within that jvm so that i get the same environment (loaded and initialized classes) for my test class. Is it possible to indicate that ,say through a jvm parameter, that it should not initialize a new vm to execute my class but instead go and execute on the remote vm and show me the result here, on my console. So the local jvm acts as a kind of thin proxy ? I am not aware in case there are some tools that should make this possible ... also heard somewhere that java 6 jvm comes with an option like this , is that true ?? Please help me. Thanks,

    Read the article

  • get_post_meta return empty string

    - by Jean-philippe Emond
    I guest it is a little issues but I running a SQL to get some post id. $result = $wpdb->get_results("SELECT wppm.post_id FROM wp_postmeta wppm INNER JOIN wp_posts wpp ON wppm.post_id=wpp.ID WHERE wppm.meta_key LIKE 'activity'"); (count: 302) After that, I get all id and I run get_post_meta like that: foreach($result as $id){ $activity = get_post_meta($id); var_dump($activity); foreach($activity as $key=>$value){ if(is_array($value) && $key=="age"){ var_dump($value); } } } (var_dump result: string "") samething if I run with: $activity = get_post_meta($id,'activity',true); Where we need to get a result. What is wrong? Thank you for your help!!! [Bonus Question] If the "activity" meta_key as an array Value. and I get directly like: $result = $wpdb->get_results("SELECT wppm.meta_value FROM wp_postmeta wppm INNER JOIN wp_posts wpp ON wppm.post_id=wpp.ID WHERE wppm.meta_key LIKE 'activity'"); How I parse it? Thanks again!

    Read the article

  • MySQL: filling empty fields with zeroes when using GROUP BY

    - by SaltLake
    I've got MySQL table CREATE TABLE cms_webstat ( ID int NOT NULL auto_increment PRIMARY KEY, TIMESTAMP_X timestamp DEFAULT CURRENT_TIMESTAMP, # ... some other fields ... ) which contains statistics about site visitors. For getting visits per hour I use SELECT hour(TIMESTAMP_X) as HOUR , count(*) AS HOUR_STAT FROM cms_webstat GROUP BY HOUR ORDER BY HOUR DESC which gives me | HOUR | HOUR_STAT | | 24 | 15 | | 23 | 12 | | 22 | 9 | | 20 | 3 | | 18 | 2 | | 15 | 1 | | 12 | 3 | | 9 | 1 | | 3 | 5 | | 2 | 7 | | 1 | 9 | | 0 | 12 | And I'd like to get following: | HOUR | HOUR_STAT | | 24 | 15 | | 23 | 12 | | 22 | 9 | | 21 | 0 | | 20 | 3 | | 19 | 0 | | 18 | 2 | | 17 | 0 | | 16 | 0 | | 15 | 1 | | 14 | 0 | | 13 | 0 | | 12 | 3 | | 11 | 0 | | 10 | 0 | | 9 | 1 | | 8 | 0 | | 7 | 0 | | 6 | 0 | | 5 | 0 | | 4 | 0 | | 3 | 5 | | 2 | 7 | | 1 | 9 | | 0 | 12 | How should I modify the query to get such result? Thanks.

    Read the article

  • Storing object as a column in LINQ

    - by Alex
    Hello, i have some class which constructs itself from string, like this: CurrencyVector v = new CurrencyVector("10 WMR / 20 WMZ"); it's actually a class which holds multiple currency values, but it does not matter much. I need to change type of column in my LINQ table (in vs 2010 designer) from String to that class, CurrencyVector. If i do it - i get runtime error when LINQ runtime tries to cast String as CurrencyVector (when populating the table from database). Adding IConvertible did not help. I wrapped these columns in properties, but it's ugly and slow solution. Searching internet gave no results.

    Read the article

  • How can i use 'log' inside a src/groovy/ class

    - by firnnauriel
    I'm encountering this error: groovy.lang.MissingPropertyException: No such property: log for class: org.utils.MyClass Here's the content of the class: package org.utils class MyClass { int organizationCount = 0 public int getOrganizationCount(){ log.debug "There are ${organizationCount} organization(s) found." return organizationCount } } Do i need to add an import statement? What do i need to add? Note that the class is located in src/groovy/org/utils. I know that the 'log' variable is accessible in controllers, services, etc. Not sure in 'src' classes. Thanks.

    Read the article

  • Choosing a design pattern for a class that might change it's internal attributes

    - by the_drow
    I have a class that holds arbitrary state and it's defined like this: class AbstractFoo { }; template <class StatePolicy> class Foo : public StatePolicy, public AbstractFoo { }; The state policy contains only protected attributes that represent the state. The state might be the same for multiple behaviors and they can be replaced at runtime. All Foo objects have the same interface to abstract the state itself and to enable storing Foo objects in containers. I would like to find the least verbose and the most maintainable way to express this.

    Read the article

  • how to pass a variable value from one class to another

    - by Arunabha
    I have two packages one is com.firstBooks.series.db.parser which have a java file XMLParser.java, I have another package com.firstBooks.series79 which have a class called AppMain.NW I want to send the value of a variable called _xmlFileName frm AppMain class to the xmlFile variable in XMLParser class, I am posting the code for both the class, kindly help me. package com.firstBooks.series.db.parser; import java.io.IOException; import java.io.InputStream; import java.util.Vector; import net.rim.device.api.xml.parsers.DocumentBuilder; import net.rim.device.api.xml.parsers.DocumentBuilderFactory; import net.rim.device.api.xml.parsers.ParserConfigurationException; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; import com.firstBooks.series.db.Question; public class XMLParser { private Document document; public static Vector questionList; public static String xmlFile; public XMLParser() { questionList = new Vector(); } public void parseXMl() throws SAXException, IOException, ParserConfigurationException { // Build a document based on the XML file. DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); InputStream inputStream = getClass().getResourceAsStream(xmlFile); document = builder.parse(inputStream); } public void parseDocument() { Element element = document.getDocumentElement(); NodeList nl = element.getElementsByTagName("question"); if (nl != null && nl.getLength() > 0) { for (int i = 0; i < nl.getLength(); i++) { Element ele = (Element) nl.item(i); Question question = getQuestions(ele); questionList.addElement(question); } } } private Question getQuestions(Element element) { String title = getTextValue(element, "title"); String choice1 = getTextValue(element, "choice1"); String choice2 = getTextValue(element, "choice2"); String choice3 = getTextValue(element, "choice3"); String choice4 = getTextValue(element, "choice4"); String answer = getTextValue(element, "answer"); String rationale = getTextValue(element, "rationale"); Question Questions = new Question(title, choice1, choice2, choice3, choice4, answer, rationale); return Questions; } private String getTextValue(Element ele, String tagName) { String textVal = null; NodeList nl = ele.getElementsByTagName(tagName); if (nl != null && nl.getLength() > 0) { Element el = (Element) nl.item(0); textVal = el.getFirstChild().getNodeValue(); } return textVal; } } Nw the code for AppMain class //#preprocess package com.firstBooks.series79; import net.rim.device.api.ui.UiApplication; import com.firstBooks.series.ui.screens.HomeScreen; public class AppMain extends UiApplication { public static String _xmlFileName; public static boolean _Lite; public static int _totalNumofQuestions; public static void initialize(){ //#ifndef FULL /* //#endif _xmlFileName = "/res/Series79_FULL.xml"; _totalNumofQuestions = 50; _Lite = false; //#ifndef FULL */ //#endif //#ifndef LITE /* //#endif _xmlFileName = "/res/Series79_LITE.xml"; _totalNumofQuestions = 10; _Lite = true; //#ifndef LITE */ //#endif } private AppMain() { initialize(); pushScreen(new HomeScreen()); } public static void main(String args[]) { new AppMain().enterEventDispatcher(); } }

    Read the article

  • Dispose a Web Service Proxy class?

    - by Matt
    When you create and use a Web Service proxy class in the ASP.Net framework, the class ultimately inherits from Component, which implements IDisposable. I have never seen one example online where people dispose of a web proxy class, but was wondering if it really needs to be done. When I call only one method, I normally wrap it in a using statement, but if I have a need to call it several times throughout the page, I might end up using the same instance, and just wondered what the ramifications are of not disposing it.

    Read the article

  • Use of type 'id' in cocoa class

    - by gotye
    Hey guys, I want to implement a class which can be used by two classes of my project. One is manipulating 'NewsRecord' objects. One is manipulating 'GalleriesRecord' objects. In another class, I may use one of the two objects so i do something like that : // header class id myNewsRecordOrGalleriesRecord; // class.m // NewsRecord and GalleriesRecord have both the title property NSLog(myNewsRecordOrGalleriesRecord.title); and i get : error : request for member 'title' in something not a structure or union any ideas :D ? Thanks. Gotye How am I supposed to do it ?

    Read the article

  • Retrieve class name hierarchy as string

    - by Jeff Wain
    Our system complexity has risen to the point that we need to make permission names tied to the client from the database more specific. In the client, permissions are referenced from a static class since a lot of client functionality is dependent on the permissions each user has and the roles have a ton of variety. I've referenced this post as an example, but I'm looking for a more specific use case. Take for instance this reference, where PermissionAlpha would be a const string: return HasPermission(PermissionNames.PermissionAlpha); Which is great, except now that things are growing more complex the classes are being structured like this: public static class PermissionNames { public static class PermissionAlpha { public const string SubPermission; } } I'm trying to find an easy way to reference PermissionAlpha in this new setup that will act similar to the first declaration above. Would the only way to do this be to resort to pulling the value of the class name like in the example below? I'm trying to keep all the names in one place that can be reference anywhere in the application. public static class PermissionAlpha { public static string Name { get { return typeof(PermissionAlpha).Name; } } }

    Read the article

  • Question of using static_cast on "this" pointer in a derived object to base class

    - by Johnyy
    Hi, this is an example taken from Effective C++ 3ed, it says that if the static_cast is used this way, the base part of the object is copied, and the call is invoked from that part. I wanted to understand what is happening under the hood, will anyone help? class Window { // base class public: virtual void onResize() { } // base onResize impl }; class SpecialWindow: public Window { // derived class public: virtual void onResize() { // derived onResize impl; static_cast<Window>(*this).onResize(); // cast *this to Window, // then call its onResize; // this doesn't work! // do SpecialWindow- } // specific stuff };

    Read the article

  • Defining a recursive function in a Prototype class?

    - by btl
    I'm trying to create an image rotator class that cycles through an arbitrary number of images in an unordered list. Is it possible to define a recursive function within a class declaration? E.g: var Rotator = Class.create() { initialize: function() { do something... this.rotate(); } rotate: function() { do something... this.rotate() } }

    Read the article

  • Java: Make a method abstract for each extending class

    - by Martijn Courteaux
    Hi, Is there any keyword or design pattern for doing this? public abstract class Root { public abstract void foo(); } public abstract class SubClass extends Root { public void foo() { // Do something } } public class SubberClass extends SubClass { // Here is it not necessary to override foo() // So is there a way to make this necessary? // A way to obligate the developer make again the override } Thanks

    Read the article

  • friend declaration block an external function access to the private section of a class

    - by MiP
    I'm trying to force function caller from a specific class. For example this code bellow demonstrate my problem. I want to make 'use' function would be called only from class A. I'm using a global namespace all over the project. a.h #include "b.h" namespace GLOBAL{ class A{ public: void doSomething(B); } } a.cpp #include "a.h" using namespace GLOBAL; void A::doSomething(B b){ b.use(); } b.h namespace GLOBAL{ class B{ public: friend void GLOBAL::A::doSomething(B); private: void use(); } Compiler says: ‘GLOBAL::A’ has not been declared ‘void GLOBAL::B::use()’ is private Can anyone help here ? Thanks a lot, Mike.

    Read the article

< Previous Page | 109 110 111 112 113 114 115 116 117 118 119 120  | Next Page >