Search Results

Search found 4652 results on 187 pages for 'explicit constructor'.

Page 124/187 | < Previous Page | 120 121 122 123 124 125 126 127 128 129 130 131  | Next Page >

  • Creating a Dib by only specifying the size with GDI+ and DotNet...

    - by Kris Erickson
    I have just recently discovered the difference between different constructors in GDI+. Going: var bmp = new Bitmap(width, height, pixelFormat); creates a DDB (Device Dependent Bitmap) whereas: var bmp = new Bitmap(someFile); creates a DIB (Device Independent Bitmap). This is really not usually important, except when handling very large images (where a DDB will run out of memory, and run out of memory at different sizes depending on the machine and its video memory). I need to create a DIB rather than DDB, but specify the height, width and pixelformat. Does anyone know how to do this in DotNet. Also is there a guide to what type of Bitmap (DIB or DDB) is being created by which Bitmap constructor?

    Read the article

  • How often do you implement the big three?

    - by Neil Butterworth
    I was just musing about the number of questions here that either are about the "big three" (copy constructor, assignment operator and destructor) or about problems caused by them not being implemented correctly, when it occurred to me that I could not remember the last time I had implemented them myself. A swift grep on my two most active projects indicate that I implement all three in only one class out of about 150. That's not to say I don't implement/declare one or more of them - obviously base classes need a virtual destructor, and a large number of my classes forbid copying using the private copy ctor & assignment op idiom. But fully implemented, there is this single lonely class, which does some reference counting. So I was wondering am I unusual in this? How often do you implement all three of these functions? Is there any pattern to the classes where you do implement them?

    Read the article

  • Pass Session data to a Class Library without using a bunch of constructors?

    - by sah302
    Hi all, I've got my application here where literally every object has a lastUpdatedBy property. The information I put into here is the person's username, which is retrieved from the session("username") variable. How can I pass this data to my DAL in the class library? At first I was just passing in the value into each method, but this is ridiculous I thought, there should be no reason to do that every time a method is called. Then I thought well if I just put it in a constructor for each of the DAL related classes, that will make it even easier. However, even still on any given page, I've got a plethora of New() declarations, for which every single line I need to pass in the session username casted as a string. Is there an even still more efficient way of doing this so that I could only declare this in one place, and everything will know what it is and I can pass it to classes in a class library?

    Read the article

  • Injecting a dependancy into a base class

    - by Jamie Dixon
    Hey everyone, I'm on a roll today with questions. I'm starting out with Dependency Injection and am having some trouble injecting a dependency into a base class. I have a BaseController controller which my other controllers inherit from. Inside of this base controller I do a number of checks such as determining if the user has the right privileges to view the current page, checking for the existence of some session variables etc. I have a dependency inside of this base controller that I'd like to inject using Ninject however when I set this up as I would for my other dependencies I'm told by the compiler that: Error 1 'MyProject.Controllers.BaseController' does not contain a constructor that takes 0 argument This makes sense but I'm just not sure how to inject this dependency. Should I be using this pattern of using a base controller at all or should I be doing this in a more efficient/correct way?

    Read the article

  • Argument type deduction, references and rvalues

    - by uj2
    Consider the situation where a function template needs to forward an argument while keeping it's lvalue-ness in case it's a non-const lvalue, but is itself agnostic to what the argument actually is, as in: template <typename T> void target(T&) { cout << "non-const lvalue"; } template <typename T> void target(const T&) { cout << "const lvalue or rvalue"; } template <typename T> void forward(T& x) { target(x); } When x is an rvalue, instead of T being deduced to a constant type, it gives an error: int x = 0; const int y = 0; forward(x); // T = int forward(y); // T = const int forward(0); // Hopefully, T = const int, but actually an error forward<const int>(0); // Works, T = const int It seems that for forward to handle rvalues (without calling for explicit template arguments) there needs to be an forward(const T&) overload, even though it's body would be an exact duplicate. Is there any way to avoid this duplication?

    Read the article

  • default value for a static property

    - by Blitzz
    I like c#, but why can I do : public static bool Initialized { private set; get; } or this : public static bool Initialized = false; but not a mix of both in one line ? I just need to set access level to my variable (private set), and I need it set at false on startup. I wouldn't like to make that boring private _Initialized variable, which would be returned by the getter of the public Initialized var. I like my code to be beautiful. (NB: my variable is static, it can't be initialized in the constructor). Thanks

    Read the article

  • How do I pass an array to a method?

    - by ambidextorous
    Hey, I have not been able to find a proper answer on any forums about this. But how exactly do I pass an array to a class constructor? public class TestArray { String name; String[] array; public TestArray(String name, String[] anArray){ this.name = name; int len = anArray.length; this.array = new String[len]; for (int i = 0; i < len; i++) { this.array[i] = new String(anArray[i]); } } public static void main(String[] args){ String[] anArray = new String[2]; anArray[0] = new String("Test"); anArray[1] = new String("Test2"); TestArray work = new TestArray("Jordan", anArray); // How to pass the array? } }

    Read the article

  • Spring @Value annotation not using defaults when property is not present

    - by garyj
    Hi All I am trying to use @Value annotation in the parameters of a constructor as follows: @Autowired public StringEncryptor( @Value("${encryptor.password:\"\"}") String password, @Value("${encryptor.algorithm:\"PBEWithMD5AndTripleDES\"}") String algorithm, @Value("${encryptor.poolSize:10}") Integer poolSize, @Value("${encryptor.salt:\"\"}") String salt) { ... } When the properties file is present on the classpath, the properties are loaded perfectly and the test executes fine. However when I remove the properties file from the classpath, I would have expected that the default values would have been used, for example poolSize would be set to 10 or algorithm to PBEWithMD5AndTripleDES however this is not the case. Running the code through a debugger (which would only work after changing @Value("${encryptor.poolSize:10}") Integer poolSize to @Value("${encryptor.poolSize:10}") String poolSize as it was causing NumberFormatExceptions) I find that the defaults are not being set and the parameters are in the form of: poolSize = ${encryptor.poolSize:10} or algorithm = ${encryptor.algorithm:"PBEWithMD5AndTripleDES"} rather than the expected poolSize = 10 or algorithm = "PBEWithMD5AndTripleDES" Based on SPR-4785 the notation such as ${my.property:myDefaultValue} should work. Yet it's not happening for me! Thank you

    Read the article

  • TStringList and TThread that does not free all of its memory

    - by VanillaH
    Version used: Delphi 7. I'm working on a program that does a simple for loop on a Virtual ListView. The data is stored in the following record: type TList=record Item:Integer; SubItem1:String; SubItem2:String; end; Item is the index. SubItem1 the status of the operations (success or not). SubItem2 the path to the file. The for loop loads each file, does a few operations and then, save it. The operations take place in a TStringList. Files are about 2mb each. Now, if I do the operations on the main form, it works perfectly. Multi-threaded, there is a huge memory problem. Somehow, the TStringList doesn't seem to be freed completely. After 3-4k files, I get an EOutofMemory exception. Sometimes, the software is stuck to 500-600mb, sometimes not. In any case, the TStringList always return an EOutofMemory exception and no file can be loaded anymore. On computers with more memory, it takes longer to get the exception. The same thing happens with other components. For instance, if I use THTTPSend from Synapse, well, after a while, the software cannot create any new threads because the memory consumption is too high. It's around 500-600mb while it should be, max, 100mb. On the main form, everything works fine. I guess the mistake is on my side. Maybe I don't understand threads enough. I tried to free everything on the Destroy event. I tried FreeAndNil procedure. I tried with only one thread at a time. I tried freeing the thread manually (no FreeOnTerminate...) No luck. So here is the thread code. It's only the basic idea; not the full code with all the operations. If I remove the LoadFile prodecure, everything works good. A thread is created for each file, according to a thread pool. unit OperationsFiles; interface uses Classes, SysUtils, Windows; type TOperationFile = class(TThread) private Position : Integer; TPath, StatusMessage: String; FileStringList: TStringList; procedure UpdateStatus; procedure LoadFile; protected procedure Execute; override; public constructor Create(Path: String; LNumber: Integer); end; implementation uses Form1; procedure TOperationFile.LoadFile; begin try FileStringList.LoadFromFile(TPath); // Operations... StatusMessage := 'Success'; except on E : Exception do StatusMessage := E.ClassName; end; end; constructor TOperationFile.Create(Path : String; LNumber: Integer); begin inherited Create(False); TPath := Path; Position := LNumber; FreeOnTerminate := True; end; procedure TOperationFile.UpdateStatus; begin FileList[Position].SubItem1 := StatusMessage; Form1.ListView4.UpdateItems(Position,Position); end; procedure TOperationFile.Execute; begin FileStringList:= TStringList.Create; LoadFile; Synchronize(UpdateStatus); FileStringList.Free; end; end. What could be the problem? I thought at one point that, maybe, too many threads are created. If a user loads 1 million files, well, ultimately, 1 million threads is going to be created -- although, only 50 threads are created and running at the same time. Thanks for your input.

    Read the article

  • Design pattern to encapsulate common funtionality among UI controls

    - by Dan
    I'm brainstorming some ideas around a pattern to use for the following scenario. I have some 3rd party controls that I want to add common functionality to. Functionality is added by handling several of the the events and doing certain things when the events fire along with adding some private variables to hold some state info between events. I want to reuse the code and functionality so this is what I'd typically do. Create a class for this functionality and pass in the instance of the control that I want to add the functionality to in the constructor. Then I can add event handlers to the control in the instance of the class. Can anyone think of alternative patterns to use in order to create this kind of reusable functionality.

    Read the article

  • silverlight adding single prism command delegate to a list of items in xaml

    - by bobwah
    I'm building a menu using Prism (using a trtelerik tree view with hierarchy data templates but hopefully the details don't matter) and I'm trying to set up a Click.Command on each menu items bindings that will all call the same delegate command which is defined in the view model. The menu is built up out of items which I don't really want to put any references to the command in. How do I bind the command to each of these items in xaml? I've looked around and it looks like in WPF I could use a relative source binding and find ancestors but there doesn't seem to be a way of doing this in silverlight. Can I setup the delegate as a static resource somehow? I don't think I can create a static resource to the view model as this uses Unity to resolve paramters to it's constructor.

    Read the article

  • Is this a good way to identify the type of a javascript object?

    - by FK82
    Apparently neither instanceof nor typeof deliver in terms of correctly identifying the type of every javascript object. I have come up with this function and I'm looking for some feedback: function getType() { var input = arguments[0] ; var types = ["String","Array","Object","Function","HTML"] ; //!! of the top of my head for(var n=0; n < types.length; n++) { if( input.constructor.toString().indexOf( types[n] ) != -1) { document.write( types[n] ) ; } } } Thanks for reading!

    Read the article

  • Dynamically Loading a DLL

    - by TooFat
    I am trying to simply load a dll written in C# at run time and create an instance of a class in that dll. Assembly a = Assembly.LoadFrom(@"C:\Development\DaDll.dll"); Type type = a.GetType("FileReleaseHandler", true); TestInterface.INeeedHelp handler = Activator.CreateInstance(type) as TestInterface.INeeedHelp; No errors are thrown, and if I step through the code I can walk though the FileReleaseHandler Class as it executes the constructor but the value of handler is always null. What am I missing here? or even is there a better way I should be going about this?

    Read the article

  • Which isolation level should I use for the following insert-if-not-present transaction?

    - by Steve Guidi
    I've written a linq-to-sql program that essentially performs an ETL task, and I've noticed many places where parallelization will improve its performance. However, I'm concerned about preventing uniquness constraint violations when two threads perform the following task (psuedo code). Record CreateRecord(string recordText) { using (MyDataContext database = GetDatabase()) { Record existingRecord = database.MyTable.FirstOrDefault(record.KeyPredicate()); if(existingRecord == null) { existingRecord = CreateRecord(recordText); database.MyTable.InsertOnSubmit(existingRecord); } database.SubmitChanges(); return existingRecord; } } In general, this code executes a SELECT statement to test for record existance, followed by an INSERT statement if the record doesn't exist. It is encapsulated by an implicit transaction. When two threads run this code for the same instance of recordText, I want to prevent them from simultaneously determining that the record doesn't exist, thereby both attempting to create the same record. An isolation level and explicit transaction will work well, except I'm not certain which isolation level I should use -- Serializable should work, but seems too strict. Is there a better choice?

    Read the article

  • Best practice for passing configuration to each GUI object

    - by Laimoncijus
    Hi, I am writing an application, where I do have few different windows implemented, where each window is a separate class. Now I need somehow to pass a single configuration object to all of them. My GUI is designed in way, where I have one main window, which may create some child windows of its own, and these child windows can have their own childs (so there is no possibility to create all windows in initialization part and feed the config object to all of them from the very beginning)... What would be best practice for sharing this configuration object between them? Always passing via constructor or maybe making it somewhere as final public static and let each window object to access it when needed? Thanks

    Read the article

  • How do i get file path of my file in java enterprise application?

    - by Nitesh Panchal
    Hello, I created java enterprise application and it consists of ejb module and web application. I have plain old xml file in source packages folder in package "common" in my ejb module. I want to pass this file path in File() constructor for one class in ejb module. How do i do it? If i pass any of the below it doesn't work :- new File("abc.xml"); //this take file from glassfish/domains/domain1 :( new File("./abc.xml"); I don't want to pass hardcode path like /home/administrator/appname/module/etc.. I want the path relative from my ejb module. Please help me. I've tried all things. Actually when i created a class in same folder and then try classname.getResource("abc.xml").getPath() it works fine. But what if i don't have any class in that folder. Waiting for your replies

    Read the article

  • Memory leak in C++ program.

    - by lampshade
    What I have is a very crude linked list..THe problem for me is that I am getting a memory leak in the constructor or main. I think it is the constructor. I have not yet deleted the eventName varaible that I have allocated memory for. Could someone help please? :/ (This is not a homework question) class Event { private: char * eventName ; string userEvent; struct node { node(); node * nextByName; const char * eventName; }; node * headByName; public: Event(const char * eventName, const Date &myDate); Event(); virtual ~Event(); void insert(const char * eventName, const Date &myDate, const Time &myTime); void setEvent(); const char * const getEvent() const { return userEvent.c_str(); }; void displayByName(ostream& out) const; }; Event::Event(const char * eventName, const Date &myDate) : eventName(new char[strlen(eventName)+1]), headByName(NULL), userEvent("") { if (eventName) { size_t length = strlen(eventName) +1; strcpy_s(this->eventName, length, eventName); } else eventName = NULL; } Event::Event() : eventName(NULL), userEvent(NULL), headByName(NULL) { } Event::~Event() { node * temp_node = NULL; node * current_node = headByName; while ( current_node ) { temp_node = current_node->nextByName; delete current_node; current_node = temp_node; } } void Event::insert(const char * eventName, const Date &myDate, const Time &myTime) // when we insert we dont care about the time, just the name and the date { node * current_node = new node(); if ( headByName == NULL ) { headByName = current_node; headByName->eventName = eventName; } else { node * search_node = headByName; node * prev_node = NULL; while ( search_node != NULL ) { prev_node = search_node; search_node = search_node->nextByName; } if ( NULL == prev_node ) { headByName = current_node; } else { prev_node->nextByName = current_node; } current_node->nextByName = search_node; current_node->eventName = eventName ; } } void Event::displayByName(ostream& out) const { cout << "Scheduled Events are: " << endl << endl; node * current_node = headByName; while ( current_node ) { (char*)eventName = (char*)current_node->eventName; out << eventName << endl; current_node = current_node->nextByName; } } Event::node::node() : nextByName(NULL), eventName(NULL) { } void Event::setEvent() { cout << "\n\nEnter a new event! "; cin.getline((char*)userEvent.c_str(), 256); size_t length = strlen(userEvent.c_str()) +1; strcpy_s((char*)this->userEvent.c_str(), length, userEvent.c_str()); } /********************************************************************************* **********************************************************************************/ int main() { Date * dPtr = new Date("March", 21, 2010); // instaintiate our Date class object by allocating default date paramateres. Event * ePtr = new Event("First Day of Spring", *dPtr); Time * tPtr = new Time(10,12,"PM"); cout << "default Time is: " << tPtr << endl; cout << "default Date is: " << dPtr << endl; ePtr->insert("First Day of Spring",*dPtr, *tPtr); ePtr->insert("Valentines Day", Date("February",14,2010), *tPtr); ePtr->insert("New Years Day", Date("Janurary",1,2011), *tPtr); ePtr->insert("St. Patricks Day", Date("March",17,2010), *tPtr); ePtr->displayByName(cout); ePtr->setEvent(); const char * const theEvent = ePtr->getEvent(); dPtr->setDate(); ePtr->insert(theEvent, *dPtr, *tPtr); tPtr->setTime(); cout << "Your event: " << theEvent << " is scheduled for: " << endl << dPtr << "at" << tPtr; ePtr->displayByName(cout); delete tPtr; delete dPtr; delete ePtr; cin.ignore(); return 0; }

    Read the article

  • Generics and reflection in Java

    - by Ragesh
    This is probably a very basic question, but I'm really new to generics in Java and I'm having a hard time altering my thought process from the way things are done in C#, so bear with me. I'm trying to build a generic repository in Java. I've created an IRepository interface that looks like this: public interface IRepository<T extends IEntity> And a Repository class that looks like this: public class Repository<T extends IEntity> implements IRepository<T> Now, from within the constructor of my Repository class, I'd like to be able to "divine" the exact type of T. For example, if I instantiated a repository like this: IRepository<MyClass> repo = new Repository<MyClass>(); I'd like to know that T is actually MyClass. This is trivial in C#, but obviously generics are a totally different beast in Java and I can't seem to find anything that would help me do this.

    Read the article

  • Opinions about Dabo

    - by driverate
    Has anyone used Dabo lately? How does it rate vs Boa Constructor, etc? I'm writing a new Python database app and Dabo looks promising, but what's the real-world scoop on it? Is it used by many developers? It's not talked about very much here on SO, or anywhere, as far as I can tell. I'm just a little concerned that the support community might be too small, or the possibility that writers might decide to throw in the towel. What is your assessment of Dabo?

    Read the article

  • Java - Thread safety of ArrayList constructors

    - by andy boot
    I am looking at this piece of code. This constructor delegates to the native method "System.arraycopy" Is it Thread safe? And by that I mean can it ever throw a ConcurrentModificationException? public Collection<Object> getConnections(Collection<Object> someCollection) { return new ArrayList<Object>(someCollection); } Does it make any difference if the collection being copied is ThreadSafe eg a CopyOnWriteArrayList? public Collection<Object> getConnections(CopyOnWriteArrayList<Object> someCollection) { return new ArrayList<Object>(someCollection); }

    Read the article

  • Code Analysis Warning CA1004 with generic method

    - by Vaccano
    I have the following generic method: // Load an object from the disk public static T DeserializeObject<T>(String filename) where T : class { XmlSerializer xmlSerializer = new XmlSerializer(typeof(T)); try { TextReader textReader = new StreamReader(filename); var result = (T)xmlSerializer.Deserialize(textReader); textReader.Close(); return result; } catch (FileNotFoundException) { } return null; } When I compile I get the following warning: CA1004 : Microsoft.Design : Consider a design where 'MiscHelpers.DeserializeObject(string)' doesn't require explicit type parameter 'T' in any call to it. I have considered this and I don't know a way to do what it requests with out limiting the types that can be deserialized. I freely admit that I might be missing an easy way to fix this. But if I am not, then is my only recourse to suppress this warning? I have a clean project with no warnings or messages. I would like to keep it that way. I guess I am asking "why this is a warning?" At best this seems like it should be a message. And even that seems a bit much. Either it can or it can't be fixed. If it can't then you are just stuck with the warning with no recourse but suppressing it. Am I wrong?

    Read the article

  • How to synchronize static method in java.

    - by Summer_More_More_Tea
    Hi there: I come up with this question when implementing singleton pattern in Java. Even though the example listed blow is not my real code, yet very similar to the original one. public class ConnectionFactory{ private static ConnectionFactory instance; public static synchronized ConnectionFactory getInstance(){ if( instance == null ){ instance = new ConnectionFactory(); } return instance; } private ConnectionFactory(){ // private constructor implementation } } Because I'm not quite sure about the behavior of a static synchronized method, I get some suggestion from google -- do not have (or as less as possible) multiple static synchronized methods in the same class. I guess when implementing static synchronized method, a lock belongs to Class object is used so that multiple static synchronized methods may degrade performance of the system. Am I right? or JVM use other mechanism to implement static synchronized method? What's the best practice if I have to implement multiple static synchronized methods in a class? Thank you all! Kind regards!

    Read the article

  • Explanation of output

    - by Anon
    My program class Building { Building() { System.out.print("b "); } Building(String name) { this(); System.out.print("bn " + name); } }; public class House extends Building { House() { System.out.print("h "); // this is line# 1 } House(String name) { this(); // This is line#2 System.out.print("hn " + name); } public static void main(String[] args) { new House("x "); } } We know that compiler will write a call to super() as the first line in the child class's constructor. Therefore should not the output be: b (call from compiler written call to super(), before line#2 b (again from compiler written call to super(),before line#1 ) h hn x But the output is b h hn x Why is that?

    Read the article

  • File mkdirs() method not working in android/java

    - by Leif Andersen
    I've been pulling out my hair on this for a while now. The following method is supposed to download a file, and save it to the location specified on the hard drive. private static void saveImage(Context context, boolean backgroundUpdate, URL url, File file) { if (!Tools.checkNetworkState(context, backgroundUpdate)) return; // Get the image try { // Make the file file.getParentFile().mkdirs(); // Set up the connection URLConnection uCon = url.openConnection(); InputStream is = uCon.getInputStream(); BufferedInputStream bis = new BufferedInputStream(is); // Download the data ByteArrayBuffer baf = new ByteArrayBuffer(50); int current = 0; while ((current = bis.read()) != -1) { baf.append((byte) current); } // Write the bits to the file OutputStream os = new FileOutputStream(file); os.write(baf.toByteArray()); os.close(); } catch (Exception e) { // Any exception is probably a newtork faiilure, bail return; } } Also, if the file doesn't exist, it is supposed to make the directory for the file. (And if there is another file already in that spot, it should just not do anything). However, for some reason, the mkdirs() method never makes the directory. I've tried everything from explicit parentheses, to explicitly making the parent file class, and nothing seems to work. I'm fairly certain that the drive is writable, as it's only called after that has already been determined, also that is true after running through it while debugging. So the method fails because the parent directories aren't made. Can anyone tell me if there is anything wrong with the way I'm calling it? Also, if it helps, here is the source for the file I'm calling it in: https://github.com/LeifAndersen/NetCatch/blob/master/src/net/leifandersen/mobile/android/netcatch/services/RSSService.java Thank you

    Read the article

  • undefined reference to static member variable

    - by Max
    Hi. I have this class that has a static member. it is also a base class for several other classes in my program. Here's its header file: #ifndef YARL_OBJECT_HPP #define YARL_OBJECT_HPP namespace yarlObject { class YarlObject { // Member Variables private: static int nextID; // keeps track of the next ID number to be used int ID; // the identifier for a specific object // Member Functions public: YarlObject(): ID(++nextID) {} virtual ~YarlObject() {} int getID() const {return ID;} }; } #endif and here's its implementation file. #include "YarlObject.hpp" namespace yarlObject { int YarlObject::nextID = 0; } I'm using g++, and it returns three undefined reference to 'yarlObject::YarlObject::nextID linker errors. If I change the ++nextID phrase in the constructor to just nextID, then I only get one error, and if I change it to 1, then it links correctly. I imagine it's something simple, but what's going on?

    Read the article

< Previous Page | 120 121 122 123 124 125 126 127 128 129 130 131  | Next Page >