Search Results

Search found 50247 results on 2010 pages for 'base class'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 451/2010 | < Previous Page | 447 448 449 450 451 452 453 454 455 456 457 458  | Next Page >

  • callbacks via objective-c selectors

    - by codemonkey
    I have a "BSjax" class that I wrote that lets me make async calls to our server to get json result sets, etc using the ASIHTTPRequest class. I set it up so that the BSjax class parses my server's json response, then passes control back to the calling view controller via this call: [[self delegate] performSelectorOnMainThread:@selector(bsRequestFinished:) withObject:self waitUntilDone:YES]; ... where "bsRequestFinished" is the callback method in the calling view controller. This all worked fine and well until I realized that some pages are going to need to make different types of requests... i.e. I'll want to do different types of things in that callback function depending on which type of request was made. To me it seems like being able to pass different callback function names to my BSjax class would be the cleanest fix... but I'm having trouble (and am not even sure if it's possible) to pass in a variable that holds the callback function name and then replace the call above with something like this: [[self delegate] performSelectorOnMainThread:@selector(self.variableCallbackFunctionName) withObject:self waitUntilDone:YES]; ... where "self.variableCallbackFunctionName" is set by the calling view controller when it calls BSjax to make a new request. Is this even possible? If so, advisable? If not, alternatives? EDIT: Note that whatever fix I arrive at will need to take into account the reality that this class is making async requests... so I need to make sure that the callback function processing is correctly tied to the specific requests... as I can't rely on FIFO processing sequence.

    Read the article

  • django admin site - filtering available objects for user

    - by JPG
    I have models that belong to some 'group' (Company class). I want to add users, who will also belong to a one group and should be able to edit/manage/add objects with membership in associated group. something like: class Company() class Something() company = ForeignKey(Company) user Microsoft_admin company = ForeignKey(Company) and this user should only see and edit objects belonging to associated Company in the Admin Interface. How to acomplish that?

    Read the article

  • How to limit setAccessible to only "legitimate" uses?

    - by polygenelubricants
    The more I learned about the power of setAccessible, the more astonished I am at what it can do. This is adapted from my answer to the question (Using reflection to change static final File.separatorChar for unit testing). import java.lang.reflect.*; public class EverythingIsTrue { static void setFinalStatic(Field field, Object newValue) throws Exception { field.setAccessible(true); Field modifiersField = Field.class.getDeclaredField("modifiers"); modifiersField.setAccessible(true); modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL); field.set(null, newValue); } public static void main(String args[]) throws Exception { setFinalStatic(Boolean.class.getField("FALSE"), true); System.out.format("Everything is %s", false); // "Everything is true" } } You can do truly outrageous stuff: public class UltimateAnswerToEverything { static Integer[] ultimateAnswer() { Integer[] ret = new Integer[256]; java.util.Arrays.fill(ret, 42); return ret; } public static void main(String args[]) throws Exception { EverythingIsTrue.setFinalStatic( Class.forName("java.lang.Integer$IntegerCache") .getDeclaredField("cache"), ultimateAnswer() ); System.out.format("6 * 9 = %d", 6 * 9); // "6 * 9 = 42" } } Presumably the API designers realize how abusable setAccessible can be, but must have conceded that it has legitimate uses to provide it. So my questions are: What are the truly legitimate uses for setAccessible? Could Java has been designed as to NOT have this need in the first place? What would the negative consequences (if any) of such design be? Can you restrict setAccessible to legitimate uses only? Is it only through SecurityManager? How does it work? Whitelist/blacklist, granularity, etc? Is it common to have to configure it in your applications?

    Read the article

  • mysql eliminate responses under certain condition with join

    - by Dustin
    Forgive me if this is an easy question. I teach classes and want to be able to select those students who have taken one class, but not another class. I have two tables: lessons_slots which is the table for every class such as: -------------------- -ID name slots- -1 basics 10 - -2 advanced 10 - -3 basics 10 - --------------------- The other table is class_roll, which holds enrollment info, such as: -------------------- -sID classid firstname lastname- -1 1 Jo Schmo -2 1 Person Two ... -13 2 Jo Schmo --------------------- What I want to do, I select everyone who has not had the advanced class (for example). I've tried doing SELECT * FROM lessons_slots LEFT JOIN class_roll ON lessons_slots.ID = class_roll.classid WHERE lessons_slots.name != 'advanced' But that doesn't work. Any ideas?

    Read the article

  • open Fancybox in tabs

    - by Prashant
    Hello all. I am using PHP + jQuery + Fancybox in my project. I have multiple tabs that get created dynamically. I have got a star icon on every tab header and on clicking them I want to open a fancybox. My tabs are basically ul-li with following dynamic code. $("#tabs").append("<li class='current'><a class='tab' id='tab_" + tabCnt + "<a href='#loginBox_div' class='login_link'> <img src='star.png' style='cursor:pointer'/> </a>" + "<a href='javascript:void(0);' class='remove'>x</a></li>"); in my index file : $(document).ready(function() { $("a.login_link").fancybox({ 'titlePosition' : 'inside', 'transitionIn' : 'none', 'transitionOut' : 'none' }); }); The problem is that when I click on star icon of first tab, the loginBox_div (fancybox) opens properly. But when my second tab is created and when I click on its star icon, the fancybox is not opening although the class is applied in second and successive tabs. No javascript errors too. Please show me the way. Thank you.

    Read the article

  • how do i know how many clients are calling my WCF service function

    - by ZhengZhiren
    i am writing a program to test WCF service performance in high concurrency circumstance. On client side, i start many threads to call a WCF service function which returns a long list of data object. On server side, in that function called by my client, i need to know the number of clients calling the function. For doing that, i set a counter variable. In the beginning of the function, i add the counter by 1, but how can i decrease it after the funtion has returned the result? int clientCount=0; public DataObject[] GetData() { Interlocked.Increment(ref clientCount); List<DataObject> result = MockDb.GetData(); return result.ToArray(); Interlocked.Decrement(ref clientCount); //can't run to here... } i have seen a way in c++. Create a new class named counter. In the constructor of the counter class, increase the variable. And decrease it in the destructor. In the function, make a counter object so that its constructor will be called. And after the function returns, its destructor will be called. Like this: class counter { public: counter(){++clientCount; /* not simply like this, need to be atomic*/} ~counter(){--clientCount; /* not simply like this, need to be atomic*/} }; ... myfunction() { counter c; //do something return something; } In c# i think i can do so with the following codes, but not for sure. public class Service1 : IService1 { static int clientCount = 0; private class ClientCounter : IDisposable { public ClientCounter() { Interlocked.Increment(ref clientCount); } public void Dispose() { Interlocked.Decrement(ref clientCount); } } public DataObject[] GetData() { using (ClientCounter counter = new ClientCounter()) { List<DataObject> result = MockDb.GetData(); return result.ToArray(); } } } i write a counter class implement the IDisposable interface. And put my function codes into a using block. But it seems that it doesn't work so good. No matter how many threads i start, the clientCount variable is up to 3. Any advise would be appreciated.

    Read the article

  • How can I quickly set the iPhone deployment target in Xcode?

    - by nevan
    I was reading this great article about Base SDK and Deployment targets and decided to try it out myself. The Deployment target seems to be buried in the Build settings, and not that easy to access compared to the Base SDK target (which is right there in the General tab of the project settings). To get to the Deployment settings now I have to Get Info, go to the Build tab, then search for "Deployment". Is there a quick way to check and access the Deployment target in Xcode that I'm missing?

    Read the article

  • To Interface or Not?: Creating a polymorphic model relationship in Ruby on Rails dynamically..

    - by Globalkeith
    Please bear with me for a moment as I try to explain exactly what I would like to achieve. In my Ruby on Rails application I have a model called Page. It represents a web page. I would like to enable the user to arbitrarily attach components to the page. Some examples of "components" would be Picture, PictureCollection, Video, VideoCollection, Background, Audio, Form, Comments. Currently I have a direct relationship between Page and Picture like this: class Page < ActiveRecord::Base has_many :pictures, :as => :imageable, :dependent => :destroy end class Picture < ActiveRecord::Base belongs_to :imageable, :polymorphic => true end This relationship enables the user to associate an arbitrary number of Pictures to the page. Now if I want to provide multiple collections i would need an additional model: class PictureCollection < ActiveRecord::Base belongs_to :collectionable, :polymorphic => true has_many :pictures, :as => :imageable, :dependent => :destroy end And alter Page to reference the new model: class Page < ActiveRecord::Base has_many :picture_collections, :as => :collectionable, :dependent => :destroy end Now it would be possible for the user to add any number of image collections to the page. However this is still very static in term of the :picture_collections reference in the Page model. If I add another "component", for example :video_collections, I would need to declare another reference in page for that component type. So my question is this: Do I need to add a new reference for each component type, or is there some other way? In Actionscript/Java I would declare an interface Component and make all components implement that interface, then I could just have a single attribute :components which contains all of the dynamically associated model objects. This is Rails, and I'm sure there is a great way to achieve this, but its a tricky one to Google. Perhaps you good people have some wise suggestions. Thanks in advance for taking the time to read and answer this.

    Read the article

  • Linked lists in Java - help with assignment

    - by user368241
    Representation of a string in linked lists In every intersection in the list there will be 3 fields : The letter itself. The number of times it appears consecutively. A pointer to the next intersection in the list. The following class CharNode represents a intersection in the list : public class CharNode { private char _data; private int _value; private charNode _next; public CharNode (char c, int val, charNode n) { _data = c; _value = val; _next = n; } public charNode getNext() { return _next; } public void setNext (charNode node) { _next = node; } public int getValue() { return _value; } public void setValue (int v) { value = v; } public char getData() { return _data; } public void setData (char c) { _data = c; } } The class StringList represents the whole list : public class StringList { private charNode _head; public StringList() { _head = null; } public StringList (CharNode node) { _head = node; } } Add methods to the class StringList according to the details : (I will add methods gradually according to my specific questions) (Pay attention, these are methods from the class String and we want to fulfill them by the representation of a string by a list as explained above) public int indexOf (int ch) - returns the index in the string it is operated on of the first appeareance of the char "ch". If the char "ch" doesn't appear in the string, returns -1. If the value of fromIndex isn't in the range, returns -1. Pay attention to all the possible error cases. Write what is the time complexity and space complexity of every method that you wrote. Make sure the methods you wrote are effective. It is NOT allowed to use ready classes of Java. It is NOT allowed to move to string and use string operations. Here is my try to write the method indexOf (int ch). Kindly assist me with fixing the bugs so I can move on. public int indexOf (int ch) { int count = 0; charNode pose = _head; if (pose == null ) { return -1; } for (pose = _head; pose!=null && pose.getNext()!='ch'; pose = pose.getNext()) { count++; } if (pose!=null) return count; else return -1; }

    Read the article

  • c++ templates: problem with member specialization

    - by ChAoS
    I am attempting to create a template "AutoClass" that create an arbitrary class with an arbitrary set of members, such as: AutoClass<int,int,double,double> a; a.set(1,1); a.set(0,2); a.set(3,99.7); std::cout << "Hello world! " << a.get(0) << " " << a.get(1) << " " << a.get(3) << std::endl; By now I have an AutoClass with a working "set" member: class nothing {}; template < typename T1 = nothing, typename T2 = nothing, typename T3 = nothing, typename T4 = nothing, typename T5 = nothing, typename T6 = nothing> class AutoClass; template <> class AutoClass<nothing, nothing, nothing, nothing, nothing, nothing> { public: template <typename U> void set(int n,U v){} }; template < typename T1, typename T2, typename T3, typename T4, typename T5, typename T6> class AutoClass: AutoClass<T2,T3,T4,T5,T6> { public: T1 V; template <typename U> void set(int n,U v) { if (n <= 0) V = v; else AutoClass<T2,T3,T4,T5,T6>::set(n-1,v); } }; and I started to have problems implementing the corresponding "get". This approach doesn't compile: template < typename T1, typename T2, typename T3, typename T4, typename T5, typename T6> class AutoClass: AutoClass<T2,T3,T4,T5,T6> { public: T1 V; template <typename U> void set(int n,U v) { if (n <= 0) V = v; else AutoClass<T2,T3,T4,T5,T6>::set(n-1,v); } template <typename W> W get(int n) { if (n <= 0) return V; else return AutoClass<T2,T3,T4,T5,T6>::get(n-1); } template <> T1 get(int n) { if (n <= 0) return V; else return AutoClass<T2,T3,T4,T5,T6>::get(n-1); } }; Besides, it seems I need to implement get for the <nothing, nothing, nothing, nothing, nothing, nothing> specialization. Any Idea on how to solve this?

    Read the article

  • Different ways of accessing configuration parameters from a JAX-WS service

    - by ecerulm
    As far as I know I can access the web.xml <context-param>s by making my class implement ServletContextListener and use the ServletContext.getInitParam(String) to read them, but it´s cumbersome as only one instance of the class will receive the contextInitialized(ServletContextEvent sce) call, so I need to make the ServletContext an static member of the class. What other ways exist of setting conf params at deployment time and what are the recommended ones?

    Read the article

  • FluentNhibernate dynamic runtime mappings.

    - by Paul Knopf
    I am building a framework where people will be able to save items that the created by inheriting a class of mine. I will be iterating over every type in the appdomain to find classes that I want to map to nhibernate. Every class that I find will be a subclass of the inherited type. I know how to create sub types in FluentNhibernate, but every sub type requires its own ClassMap class. Since I won't know these untill runtime, there is no way I can do that. Is there a way that I can add mappings to fluent nhibernate? Note, I know this is possible without fluent nhibernate using the Cfg class, but I don't want to manage the same code two different ways.

    Read the article

  • What is the purpose of unit testing an interface repository

    - by ahsteele
    I am unit testing an ICustomerRepository interface used for retrieving objects of type Customer. As a unit test what value am I gaining by testing the ICustomerRepository in this manner? Under what conditions would the below test fail? For tests of this nature is it advisable to do tests that I know should fail? i.e. look for id 4 when I know I've only placed 5 in the repository I am probably missing something obvious but it seems the integration tests of the class that implements ICustomerRepository will be of more value. [TestClass] public class CustomerTests : TestClassBase { private Customer SetUpCustomerForRepository() { return new Customer() { CustId = 5, DifId = "55", CustLookupName = "The Dude", LoginList = new[] { new Login { LoginCustId = 5, LoginName = "tdude" }, new Login { LoginCustId = 5, LoginName = "tdude2" } } }; } [TestMethod] public void CanGetCustomerById() { // arrange var customer = SetUpCustomerForRepository(); var repository = Stub<ICustomerRepository>(); // act repository.Stub(rep => rep.GetById(5)).Return(customer); // assert Assert.AreEqual(customer, repository.GetById(5)); } } Test Base Class public class TestClassBase { protected T Stub<T>() where T : class { return MockRepository.GenerateStub<T>(); } } ICustomerRepository and IRepository public interface ICustomerRepository : IRepository<Customer> { IList<Customer> FindCustomers(string q); Customer GetCustomerByDifID(string difId); Customer GetCustomerByLogin(string loginName); } public interface IRepository<T> { void Save(T entity); void Save(List<T> entity); bool Save(T entity, out string message); void Delete(T entity); T GetById(int id); ICollection<T> FindAll(); }

    Read the article

  • Select CSS based on multiple classes

    - by Stacey
    I have a style rule I want to apply to a tag when it has TWO styles. Is there any way to perform this without javascript? In other words.. <li class='left ui-class-selector'> I want to select only if the li has both 'left' and 'ui-class-selector' classes applied.

    Read the article

  • MEF GetExports<T, TMetaDataView> returning nothing with AllowMultiple = True

    - by sohum
    I don't understand MEF very well, so hopefully this is a simple fix of how I think it works. I'm trying to use MEF to get some information about a class and how it should be used. I'm using the Metadata options to try to achieve this. My interfaces and attribute looks like this: public interface IMyInterface { } public interface IMyInterfaceInfo { Type SomeProperty1 { get; } double SomeProperty2 { get; } string SomeProperty3 { get; } } [MetadataAttribute] [AttributeUsage(AttributeTargets.Class, AllowMultiple = true)] public class ExportMyInterfaceAttribute : ExportAttribute, IMyInterfaceInfo { public ExportMyInterfaceAttribute(Type someProperty1, double someProperty2, string someProperty3) : base(typeof(IMyInterface)) { SomeProperty1 = someProperty1; SomeProperty2 = someProperty2; SomeProperty3 = someProperty3; } public Type SomeProperty1 { get; set; } public double SomeProperty2 { get; set; } public string SomeProperty3 { get; set; } } The class that is decorated with the attribute looks like this: [ExportMyInterface(typeof(string), 0.1, "whoo data!")] [ExportMyInterface(typeof(int), 0.4, "asdfasdf!!")] public class DecoratedClass : IMyInterface { } The method that is trying to use the import looks like this: private void SomeFunction() { // CompositionContainer is an instance of CompositionContainer var myExports = CompositionContainer.GetExports<IMyInterface, IMyInterfaceInfo>(); } In my case myExports is always empty. In my CompositionContainer, I have a Part in my catalog that has two ExportDefinitions, both with the following ContractName: "MyNamespace.IMyInterface". The Metadata is also loaded correctly per my exports. If I remove the AllowMultiple setter and only include one exported attribute, the myExports variable now has the single export with its loaded metadata. What am I doing wrong?

    Read the article

  • When I change templates in Netbeans, why doesn't anything happen?

    - by Matthew
    I want to modify the "Java class" template, so that the class javadoc comment includes more than just the author. In Netbeans 6.8., I go to Tools Templates Java Java Class, and modify the template. However, nothing seems to change. I tried restarting Netbeans, just in case, but the old template is still used. How do I get Netbeans to recognize changes to the template for Java Classes?

    Read the article

  • How do I get events to execute on the "main thread"

    - by William DiStefano
    I have 2 classes, one is frmMain a windows form and the other is a class in vb.NET 2003. frmMain contains a start button which executes the monitor function in the other class. My question is, I am manually adding the event handlers -- when the events are executed how do I get them to excute on the "main thread". Because when the tooltip balloon pops up at the tray icon it displays a second tray icon instead of popping up at the existing tray icon. I can confirm that this is because the events are firing on new threads because if I try to display a balloon tooltip from frmMain it will display on the existing tray icon. Here is a part of the second class (not the entire thing): Friend Class monitorFolders Private _watchFolder As System.IO.FileSystemWatcher = New System.IO.FileSystemWatcher Private _eType As evtType Private Enum evtType changed created deleted renamed End Enum Friend Sub monitor(ByVal path As String) _watchFolder.Path = path 'Add a list of Filter to specify _watchFolder.NotifyFilter = IO.NotifyFilters.DirectoryName _watchFolder.NotifyFilter = _watchFolder.NotifyFilter Or IO.NotifyFilters.FileName _watchFolder.NotifyFilter = _watchFolder.NotifyFilter Or IO.NotifyFilters.Attributes 'Add event handlers for each type of event that can occur AddHandler _watchFolder.Changed, AddressOf change AddHandler _watchFolder.Created, AddressOf change AddHandler _watchFolder.Deleted, AddressOf change AddHandler _watchFolder.Renamed, AddressOf Rename 'Start watching for events _watchFolder.EnableRaisingEvents = True End Sub Private Sub change(ByVal source As Object, ByVal e As System.IO.FileSystemEventArgs) If e.ChangeType = IO.WatcherChangeTypes.Changed Then _eType = evtType.changed notification() End If If e.ChangeType = IO.WatcherChangeTypes.Created Then _eType = evtType.created notification() End If If e.ChangeType = IO.WatcherChangeTypes.Deleted Then _eType = evtType.deleted notification() End If End Sub Private Sub notification() _mainForm.NotifyIcon1.ShowBalloonTip(500, "Folder Monitor", "A file has been " + [Enum].GetName(GetType(evtType), _eType), ToolTipIcon.Info) End Sub End Class

    Read the article

  • Effective Data Validation

    - by John Conde
    What's an effective way to handle data validation, say, from a form submission? Originally I had a bunch of if statements that checked each value and collected invalid values in an array for later retrieval (and listing). // Store errors here $errors = array(); // Hypothetical check if a string is alphanumeric if (!preg_match('/^[a-z\d]+$/i', $fieldvalue)) { $errors[$fieldname] = 'Please only use letters and numbers for your street address'; } // etc... What I did next was create a class that handles various data validation scenarios and store the results in an internal array. After data validation was complete I would check to see if any errors occurred and handle accordingly: class Validation { private $errorList = array(); public function isAlphaNumeric($string, $field, $msg = '') { if (!preg_match('/^[a-z\d]+$/i', $string)) { $this->errorList[$field] = $msg; } } // more methods here public function creditCard($cardNumber, $field, $msg = '') { // Validate credit card number } // more methods here public function hasErrors() { return count($this->errorList); } } /* Client code */ $validate = new Validation(); $validate->isAlphaNumeric($fieldvalue1, $fieldname1, 'Please only use letters and numbers for your street address'); $validate->creditCard($fieldvalue2, $fieldname2, 'Please enter a valid credit card number'); if ($validate->hasErrors()) { // Handle as appropriate } Naturally it didn't take long before this class became bloated with the virtually unlimited types of data to be validated. What I'm doing now is using decorators to separate the different types of data into their own classes and call them only when needed leaving generic validations (i.e. isAlphaNumeric()) in the base class: class Validation { private $errorList = array(); public function isAlphaNumeric($string, $field, $msg = '') { if (!preg_match('/^[a-z\d]+$/i', $string)) { $this->errorList[$field] = $msg; } } // more generic methods here public function setError($field, $msg = '') { $this->errorList[$field] = $msg; } public function hasErrors() { return count($this->errorList); } } class ValidationCreditCard { protected $validate; public function __construct(Validation $validate) { $this->validate = $validate; } public function creditCard($cardNumber, $field, $msg = '') { // Do validation // ... // if there is an error $this->validate->setError($field, $msg); } // more methods here } /* Client code */ $validate = new Validation(); $validate->isAlphaNumeric($fieldvalue, $fieldname, 'Please only use letters and numbers for your street address'); $validateCC = new ValidationCreditCard($validate); $validateCC->creditCard($fieldvalue2, $fieldname2, 'Please enter a valid credit card number'); if ($validate->hasErrors()) { // Handle as appropriate } Am I on the right track? Or did I just complicate data validation more then I needed to?

    Read the article

  • Sharing a database connection with included classes in a Sinatra application

    - by imightbeinatree
    I'm converting a part of a rails application to its own sinatra application. It has some beefy work to do and rather than have a million helps in app.rb, I've separated some of it out into classes. Without access to rails I'm rewriting finder several methods and needing access to the database inside of my class. What's the best way to share a database connection between your application and a class? Or would you recommend pushing all database work into its own class and only having the connection established there? Here is what I have in in app.rb require 'lib/myclass' configure :production do MysqlDB = Sequel.connect('mysql://user:password@host:port/db_name') end I want to access it in lib/myclass.rb class Myclass def self.find_by_domain_and_stub(domain, stub) # want to do a query here end end I've tried several things but nothing that seems to work well enough to even include as an example.

    Read the article

  • IOS restkit error

    - by user1302602
    I am sending a Post with object loader and getting this error in output window. FYI, My didFailWithError: delegate never got hit. Not sure why. `objectLoader:didFailWithError:]:` unrecognized selector `sent to class 0x123608` How did i find out what is 0x123608? I set the router in AppDelegate class and Mapping in AppDelegate too. here is a method in my class which inherit RKObjectLoaderDelegate. I am using shared singleton. [[RKObjectManager sharedManager] postObject:review usingBlock:^(RKObjectLoader *loader){ // loader.params=params, loader.objectMapping = [[RKObjectManager sharedManager].mappingProvider objectMappingForClass:[myclass class]]; loader.serializationMIMEType = RKMIMETypeJSON; // We want to send this request as JSON loader.method = RKRequestMethodPOST; loader.serializationMapping = [RKObjectMapping serializationMappingUsingBlock:^(RKObjectMapping* mapping) { [mapping mapAttributes:@"field1", @"field2",@"field3",nil]; }]; loader.targetObject = nil; loader.delegate = self; }]; }

    Read the article

  • C# Virtual method call in constructor - how to refactor?

    - by Cristi Diaconescu
    I have an abstract class for database-agnostic cursor actions. Derived from that, there are classes that implement the abstract methods for handling database-specific stuff. The problem is, the base class ctor needs to call an abstract method - when the ctor is called, it needs to initialize the database-specific cursor. I know why this shouldn't be done, I don't need that explanation! This is my first implementation, that obviously doesn't work - it's the textbook "wrong way" of doing it. The overridden method accesses a field from the derived class, which is not yet instantiated: public abstract class CursorReader { private readonly int m_rowCount; protected CursorReader() { m_rowCount = CreateCursor(sqlCmd); //virtual call ! } protected abstract int CreateCursor(string sqlCmd); } public class SqlCursorReader : CursorReader { private SqlConnection m_sqlConnection; public SqlCursorReader(string sqlCmd, SqlConnection sqlConnection) { m_sqlConnection = sqlConnection; //field initialized here } protected override int CreateCursor(string sqlCmd) { //uses not-yet-initialized member *m_sqlConnection* //so this throws a NullReferenceException var cursor = new CustomCursor(sqlCmd, m_sqlConnection); return cursor.Count(); } } I will follow up with an answer on my attempts to fix this...

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 447 448 449 450 451 452 453 454 455 456 457 458  | Next Page >