Search Results

Search found 14034 results on 562 pages for 'interface inheritance'.

Page 193/562 | < Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >

  • Can't I just use all static methods?

    - by Reddy S R
    What's the difference between the two UpdateSubject methods below? I felt using static methods is better if you just want to operate on the entities. In which situations should I go with non-static methods? public class Subject { public int Id {get; set;} public string Name { get; set; } public static bool UpdateSubject(Subject subject) { //Do something and return result return true; } public bool UpdateSubject() { //Do something on 'this' and return result return true; } } I know I will be getting many kicks from the community for this really annoying question but I could not stop myself asking it. Does this become impractical when dealing with inheritance?

    Read the article

  • A Quantity class with units

    - by Ryan Ohs
    Goals Create a class that associates a numeric quantity with a unit of measurement. Provide support for simple arithmetic and comparison operations. Implementation An immutable class (Could have been struct but I may try inheritance later) Unit is stored in an enumeration Supported operations: Addition w/ like units Subtraction w/ like units Multiplication by scalar Division by scalar Modulus by scalar Equals() >, >=, <, <=, == IComparable ToString() Implicit cast to Decimal The Source The souce can be downloaded from Github. Notes This class does not support any arithmetic that would modify the unit. This class is not suitable for manipulating currencies. Future Ideas Have a CompositeQuantity class that would allow quantities with unlike units to be combined. Similar currency class with support for allocations/distributions. Provide conversion between units. (Actually I think this would be best placed in an external service. Many situations I deal with require some sort of dynamic conversion ratio.)

    Read the article

  • USB external drive is not recognized by any OS, how to troubleshoot in Ubuntu?

    - by Breno
    First of all I would like to inform you that I saw a question similar to mine but the error was different, so here's my problem... I have an external HD samsung s2 model of 500GB and a day to day just stopped working, tried in other systems (windows and mac) however are not recognized. In the windows device manager when I insert the usb it states that the device in question are not working properly. Well, in the logs of my ubuntu 4.12 I see the following message when I insert my usb device in: [ 2967.560216] usb 7-2: new full-speed USB device number 2 using uhci_hcd [ 2967.680182] usb 7-2: device descriptor read/64, error -71 [ 2967.904176] usb 7-2: device descriptor read/64, error -71 [ 2968.120227] usb 7-2: new full-speed USB device number 3 using uhci_hcd [ 2968.240207] usb 7-2: device descriptor read/64, error -71 [ 2968.464063] usb 7-2: device descriptor read/64, error -71 [ 2968.680087] usb 7-2: new full-speed USB device number 4 using uhci_hcd [ 2969.092085] usb 7-2: device not accepting address 4, error -71 [ 2969.208155] usb 7-2: new full-speed USB device number 5 using uhci_hcd [ 2969.624076] usb 7-2: device not accepting address 5, error -71 [ 2969.624118] hub 7-0:1.0: unable to enumerate USB device on port 2 [ 4520.240340] usb 7-1: new full-speed USB device number 6 using uhci_hcd [ 4520.364079] usb 7-1: device descriptor read/64, error -71 [ 4520.588109] usb 7-1: device descriptor read/64, error -71 [ 4520.804140] usb 7-1: new full-speed USB device number 7 using uhci_hcd [ 4520.924136] usb 7-1: device descriptor read/64, error -71 [ 4521.148083] usb 7-1: device descriptor read/64, error -71 [ 4521.364105] usb 7-1: new full-speed USB device number 8 using uhci_hcd [ 4521.776237] usb 7-1: device not accepting address 8, error -71 [ 4521.888206] usb 7-1: new full-speed USB device number 9 using uhci_hcd [ 4522.296102] usb 7-1: device not accepting address 9, error -71 [ 4522.296150] hub 7-0:1.0: unable to enumerate USB device on port 1 [ 4749.036104] usb 7-2: new full-speed USB device number 10 using uhci_hcd [ 4749.156209] usb 7-2: device descriptor read/64, error -71 [ 4749.380215] usb 7-2: device descriptor read/64, error -71 [ 4749.596206] usb 7-2: new full-speed USB device number 11 using uhci_hcd [ 4749.716409] usb 7-2: device descriptor read/64, error -71 [ 4749.940110] usb 7-2: device descriptor read/64, error -71 [ 4750.156257] usb 7-2: new full-speed USB device number 12 using uhci_hcd [ 4750.572150] usb 7-2: device not accepting address 12, error -71 [ 4750.684215] usb 7-2: new full-speed USB device number 13 using uhci_hcd [ 4751.100182] usb 7-2: device not accepting address 13, error -71 [ 4751.100224] hub 7-0:1.0: unable to enumerate USB device on port 2 Here is my system: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 002: ID 08ff:2810 AuthenTec, Inc. AES2810 00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07) 00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) 00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) 00:1a.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 02) 00:1a.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 02) 00:1a.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 02) 00:1a.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 02) 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02) 00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 02) 00:1c.1 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 (rev 02) 00:1c.4 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 5 (rev 02) 00:1d.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 02) 00:1d.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 02) 00:1d.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 02) 00:1d.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 02) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 92) 00:1f.0 ISA bridge: Intel Corporation ICH9M LPC Interface Controller (rev 02) 00:1f.2 IDE interface: Intel Corporation 82801IBM/IEM (ICH9M/ICH9M-E) 2 port SATA Controller [IDE mode] (rev 02) 00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 02) 00:1f.5 IDE interface: Intel Corporation 82801IBM/IEM (ICH9M/ICH9M-E) 2 port SATA Controller [IDE mode] (rev 02) 02:01.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev ba) 02:01.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 04) 02:01.2 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 21) 09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5756ME Gigabit Ethernet PCI Express 0c:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01) Does anyone have any clue what would be the problem?

    Read the article

  • Class Design and Structure Online Web Store

    - by Phorce
    I hope I have asked this in the right forum. Basically, we're designing an Online Store and I am designing the class structure for ordering a product and want some clarification on what I have so far: So a customer comes, selects their product, chooses the quantity and selects 'Purchase' (I am using the Facade Pattern - So subsystems execute when this action is performed). My class structure: < Order > < Product > <Customer > There is no inheritance, more Association < Order has < Product , < Customer has < Order . Does this structure look ok? I've noticed that I don't handle the "Quantity" separately, I was just going to add this into the "Product" class, but, do you think it should be a class of it's own? Hope someone can help.

    Read the article

  • Multiple Object Instantiation

    - by Ricky Baby
    I am trying to get my head around object oriented programming as it pertains to web development (more specifically PHP). I understand inheritance and abstraction etc, and know all the "buzz-words" like encapsulation and single purpose and why I should be doing all this. But my knowledge is falling short with actually creating objects that relate to the data I have in my database, creating a single object that a representative of a single entity makes sense, but what are the best practises when creating 100, 1,000 or 10,000 objects of the same type. for instance, when trying to display a list of the items, ideally I would like to be consistent with the objects I use, but where exactly should I run the query/get the data to populate the object(s) as running 10,000 queries seems wasteful. As an example, say I have a database of cats, and I want a list of all black cats, do I need to set up a FactoryObject which grabs the data needed for each cat from my database, then passes that data into each individual CatObject and returns the results in a array/object - or should I pass each CatObject it's identifier and let it populate itself in a separate query.

    Read the article

  • Object Oriented programming on 8-bit MCU Case Study

    - by Calvin Grier
    I see that there's a lot of questions related to OO Programming here. I'm actually trying to find a specific resource related to embedded OO approaches for an 8 bit MCU. Several years back (maybe 6) I was looking for material related to Object Oriented programming for resource constrained 8051 microprocessors. I found an article/website with a case history of a design group that used a very small RAM part, and implemented many Object based constructs during their C design and development. I believe it was an 8051. The project was a success, and managed to stay inside the very small ROM/RAM they had available. I'm attempting to find it again, but Google can't locate it. The article was well written, and recommended a "mixed" approach using C methods for inheritance and encapsulation - if I recall correctly. Can anyone help me locate this article?

    Read the article

  • obj-c classes and sub classes (Cocos2d) conversion

    - by Lewis
    Hi I'm using this version of cocos2d: https://github.com/krzysztofzablocki/CCNode-SFGestureRecognizers Which supports the UIGestureRecognizer within a CCLayer in a cocos2d scene like so: @interface HelloWorldLayer : CCLayer <UIGestureRecognizerDelegate> { } Now I want to make this custom gesture work within the scene, attaching it to a sprite in cocos2d: #import <Foundation/Foundation.h> #import <UIKit/UIGestureRecognizerSubclass.h> @protocol OneFingerRotationGestureRecognizerDelegate <NSObject> @optional - (void) rotation: (CGFloat) angle; - (void) finalAngle: (CGFloat) angle; @end @interface OneFingerRotationGestureRecognizer : UIGestureRecognizer { CGPoint midPoint; CGFloat innerRadius; CGFloat outerRadius; CGFloat cumulatedAngle; id <OneFingerRotationGestureRecognizerDelegate> target; } - (id) initWithMidPoint: (CGPoint) midPoint innerRadius: (CGFloat) innerRadius outerRadius: (CGFloat) outerRadius target: (id) target; - (void)reset; - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event; - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event; - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event; - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event; @end #include <math.h> #import "OneFingerRotationGestureRecognizer.h" @implementation OneFingerRotationGestureRecognizer // private helper functions CGFloat distanceBetweenPoints(CGPoint point1, CGPoint point2); CGFloat angleBetweenLinesInDegrees(CGPoint beginLineA, CGPoint endLineA, CGPoint beginLineB, CGPoint endLineB); - (id) initWithMidPoint: (CGPoint) _midPoint innerRadius: (CGFloat) _innerRadius outerRadius: (CGFloat) _outerRadius target: (id <OneFingerRotationGestureRecognizerDelegate>) _target { if ((self = [super initWithTarget: _target action: nil])) { midPoint = _midPoint; innerRadius = _innerRadius; outerRadius = _outerRadius; target = _target; } return self; } /** Calculates the distance between point1 and point 2. */ CGFloat distanceBetweenPoints(CGPoint point1, CGPoint point2) { CGFloat dx = point1.x - point2.x; CGFloat dy = point1.y - point2.y; return sqrt(dx*dx + dy*dy); } CGFloat angleBetweenLinesInDegrees(CGPoint beginLineA, CGPoint endLineA, CGPoint beginLineB, CGPoint endLineB) { CGFloat a = endLineA.x - beginLineA.x; CGFloat b = endLineA.y - beginLineA.y; CGFloat c = endLineB.x - beginLineB.x; CGFloat d = endLineB.y - beginLineB.y; CGFloat atanA = atan2(a, b); CGFloat atanB = atan2(c, d); // convert radiants to degrees return (atanA - atanB) * 180 / M_PI; } #pragma mark - UIGestureRecognizer implementation - (void)reset { [super reset]; cumulatedAngle = 0; } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesBegan:touches withEvent:event]; if ([touches count] != 1) { self.state = UIGestureRecognizerStateFailed; return; } } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesMoved:touches withEvent:event]; if (self.state == UIGestureRecognizerStateFailed) return; CGPoint nowPoint = [[touches anyObject] locationInView: self.view]; CGPoint prevPoint = [[touches anyObject] previousLocationInView: self.view]; // make sure the new point is within the area CGFloat distance = distanceBetweenPoints(midPoint, nowPoint); if ( innerRadius <= distance && distance <= outerRadius) { // calculate rotation angle between two points CGFloat angle = angleBetweenLinesInDegrees(midPoint, prevPoint, midPoint, nowPoint); // fix value, if the 12 o'clock position is between prevPoint and nowPoint if (angle > 180) { angle -= 360; } else if (angle < -180) { angle += 360; } // sum up single steps cumulatedAngle += angle; // call delegate if ([target respondsToSelector: @selector(rotation:)]) { [target rotation:angle]; } } else { // finger moved outside the area self.state = UIGestureRecognizerStateFailed; } } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesEnded:touches withEvent:event]; if (self.state == UIGestureRecognizerStatePossible) { self.state = UIGestureRecognizerStateRecognized; if ([target respondsToSelector: @selector(finalAngle:)]) { [target finalAngle:cumulatedAngle]; } } else { self.state = UIGestureRecognizerStateFailed; } cumulatedAngle = 0; } - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesCancelled:touches withEvent:event]; self.state = UIGestureRecognizerStateFailed; cumulatedAngle = 0; } @end Header file for view controller: #import "OneFingerRotationGestureRecognizer.h" @interface OneFingerRotationGestureViewController : UIViewController <OneFingerRotationGestureRecognizerDelegate> @property (nonatomic, strong) IBOutlet UIImageView *image; @property (nonatomic, strong) IBOutlet UITextField *textDisplay; @end then this is in the .m file: gestureRecognizer = [[OneFingerRotationGestureRecognizer alloc] initWithMidPoint: midPoint innerRadius: outRadius / 3 outerRadius: outRadius target: self]; [self.view addGestureRecognizer: gestureRecognizer]; Now my question is, is it possible to add this custom gesture into the cocos2d project found on that github, and if so, what do I need to change in the OneFingerRotationGestureRecognizerDelegate to get it to work within cocos2d. Because at the minute it is setup in a standard iOS project and not a cocos2d project and I do not know enough about UIViews and classing/ sub classing in obj-c to get this to work. Also it seems to inherit from a UIView where cocos2d uses CCLayer. Kind regards, Lewis. I also realise I may have not included enough code from the custom gesture project for readers to interpret it fully, so the full project can be found here: https://github.com/melle/OneFingerRotationGestureDemo

    Read the article

  • Taking Object Oriented development to the next level

    - by Songo
    Can you mention some advanced OO topics or concepts that one should be aware of? I have been a developer for 2 years now and currently aiming for a certain company that requires a web developer with a minimum experience of 3 years. I imagine the interview will have the basic object oriented topics like (Abstraction, Polymorphism, Inheritance, Design patterns, UML, Databases and ORMs, SOLID principles, DRY principle, ...etc) I have these topics covered, but what I'm looking forward to is bringing up topics such as Efferent Coupling, Afferent Coupling, Instability, The law of Demeter, ...etc. Till few days ago I never knew such concepts existed (maybe because I'm a communication engineer basically not a CS graduate.) Can you please recommend some more advanced topics concerning object oriented programming?

    Read the article

  • Is functional programming a superset of object oriented?

    - by Jimmy Hoffa
    The more functional programming I do, the more I feel like it adds an extra layer of abstraction that seems like how an onion's layer is- all encompassing of the previous layers. I don't know if this is true so going off the OOP principles I've worked with for years, can anyone explain how functional does or doesn't accurately depict any of them: Encapsulation, Abstraction, Inheritance, Polymorphism I think we can all say, yes it has encapsulation via tuples, or do tuples count technically as fact of "functional programming" or are they just a utility of the language? I know Haskell can meet the "interfaces" requirement, but again not certain if it's method is a fact of functional? I'm guessing that the fact that functors have a mathematical basis you could say those are a definite built in expectation of functional, perhaps? Please, detail how you think functional does or does not fulfill the 4 principles of OOP.

    Read the article

  • Introdução ao NHibernate on TechDays 2010

    - by Ricardo Peres
    I’ve been working on the agenda for my presentation titled Introdução ao NHibernate that I’ll be giving on TechDays 2010, and I would like to request your assistance. If you have any subject that you’d like me to talk about, you can suggest it to me. For now, I’m thinking of the following issues: Domain Driven Design with NHibernate Inheritance Mapping Strategies (Table Per Class Hierarchy, Table Per Type, Table Per Concrete Type, Mixed) Mappings (hbm.xml, NHibernate Attributes, Fluent NHibernate, ConfORM) Supported querying types (ID, HQL, LINQ, Criteria API, QueryOver, SQL) Entity Relationships Custom Types Caching Interceptors and Listeners Advanced Usage (Duck Typing, EntityMode Map, …) Other projects (NHibernate Validator, NHibernate Search, NHibernate Shards, …) ASP.NET Integration ASP.NET Dynamic Data Integration WCF Data Services Integration Comments?

    Read the article

  • what is message passing in OO?

    - by Tom
    I've been studying OO programming, primarily in C++, C# and Java. I thought I had a good grasp on it with my understanding of encapsulation, inheritance and polymorphism (as well as reading a lot of questions on this site). One thing that seems to popup up here and there is the concept of "message passing". Apparently, this is something that is not used whilst OO programming in today's mainstream languages, but is supported by Smalltalk. My questions are: What is message passing? (Can someone give a practical example?) Is there any support for this "message passing" in C++, C# or Java?

    Read the article

  • Examples of Liskov Substitution

    - by james lewis
    I'm facilitating a session next week on the Liskov Substitution Principle and I was wondering if anyone had any examples of violations 'from the trenches'? I'm looking for something other than uncle Bob's rectangle - square problem and the persistent set problem he talks about in A-PPP (although that is a great example). So far I'm using the example of a (very simple) List and an IndexedList as the 'correct' use of inheritance. And the addition of a Set to this hierarchy as a violation (as a Set is distinct; strengthening the pre condition of the Add method). I've also taken this great example and it's solution from this question Both those examples are great but I'm looking for something more subtle and harder to spot. So far I've come up with nothing so if you've got a great, subtle example post it up. Also, any metaphors you've come across that helped you understand LSP would be really useful too.

    Read the article

  • Detailed C++ book for a programmer already familiar with C and object-oriented programming?

    - by Anto
    I know (to some extent) a few languages, including C, Java and Python. I'm also (somewhat) familiar with Scala and Scheme, plus I can read (but not write) x86 Assembly. Say I want to learn C++, what is a good book which doesn't try to teach me what a class is, teach me inheritance, polymorphism or loosely coupled classes again, nor does try to teach me other basics, just the C++ language (as well as how to write idiomatic C++ code, not e.g. Java with C++ syntax) and its standard library? Note: "Detailed" as used in the title means that it doesn't try to cover C++ in 100 pages, I want to know the details of the language. Of course, mastery comes from practice, but I don't want to learn just a little bit of C++ from the book, but learn it quite thoroughly.

    Read the article

  • .NET Security Part 4

    - by Simon Cooper
    Finally, in this series, I am going to cover some of the security issues that can trip you up when using sandboxed appdomains. DISCLAIMER: I am not a security expert, and this is by no means an exhaustive list. If you actually are writing security-critical code, then get a proper security audit of your code by a professional. The examples below are just illustrations of the sort of things that can go wrong. 1. AppDomainSetup.ApplicationBase The most obvious one is the issue covered in the MSDN documentation on creating a sandbox, in step 3 – the sandboxed appdomain has the same ApplicationBase as the controlling appdomain. So let’s explore what happens when they are the same, and an exception is thrown. In the sandboxed assembly, Sandboxed.dll (IPlugin is an interface in a partially-trusted assembly, with a single MethodToDoThings on it): public class UntrustedPlugin : MarshalByRefObject, IPlugin { // implements IPlugin.MethodToDoThings() public void MethodToDoThings() { throw new EvilException(); } } [Serializable] internal class EvilException : Exception { public override string ToString() { // show we have read access to C:\Windows // read the first 5 directories Console.WriteLine("Pwned! Mwuahahah!"); foreach (var d in Directory.EnumerateDirectories(@"C:\Windows").Take(5)) { Console.WriteLine(d.FullName); } return base.ToString(); } } And in the controlling assembly: // what can possibly go wrong? AppDomainSetup appDomainSetup = new AppDomainSetup { ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase } // only grant permissions to execute // and to read the application base, nothing else PermissionSet restrictedPerms = new PermissionSet(PermissionState.None); restrictedPerms.AddPermission( new SecurityPermission(SecurityPermissionFlag.Execution)); restrictedPerms.AddPermission( new FileIOPermission(FileIOPermissionAccess.Read, appDomainSetup.ApplicationBase); restrictedPerms.AddPermission( new FileIOPermission(FileIOPermissionAccess.pathDiscovery, appDomainSetup.ApplicationBase); // create the sandbox AppDomain sandbox = AppDomain.CreateDomain("Sandbox", null, appDomainSetup, restrictedPerms); // execute UntrustedPlugin in the sandbox // don't crash the application if the sandbox throws an exception IPlugin o = (IPlugin)sandbox.CreateInstanceFromAndUnwrap("Sandboxed.dll", "UntrustedPlugin"); try { o.MethodToDoThings() } catch (Exception e) { Console.WriteLine(e.ToString()); } And the result? Oops. We’ve allowed a class that should be sandboxed to execute code with fully-trusted permissions! How did this happen? Well, the key is the exact meaning of the ApplicationBase property: The application base directory is where the assembly manager begins probing for assemblies. When EvilException is thrown, it propagates from the sandboxed appdomain into the controlling assembly’s appdomain (as it’s marked as Serializable). When the exception is deserialized, the CLR finds and loads the sandboxed dll into the fully-trusted appdomain. Since the controlling appdomain’s ApplicationBase directory contains the sandboxed assembly, the CLR finds and loads the assembly into a full-trust appdomain, and the evil code is executed. So the problem isn’t exactly that the sandboxed appdomain’s ApplicationBase is the same as the controlling appdomain’s, it’s that the sandboxed dll was in such a place that the controlling appdomain could find it as part of the standard assembly resolution mechanism. The sandbox then forced the assembly to load in the controlling appdomain by throwing a serializable exception that propagated outside the sandbox. The easiest fix for this is to keep the sandbox ApplicationBase well away from the ApplicationBase of the controlling appdomain, and don’t allow the sandbox permissions to access the controlling appdomain’s ApplicationBase directory. If you do this, then the sandboxed assembly can’t be accidentally loaded into the fully-trusted appdomain, and the code can’t be executed. If the plugin does try to induce the controlling appdomain to load an assembly it shouldn’t, a SerializationException will be thrown when it tries to load the assembly to deserialize the exception, and no damage will be done. 2. Loading the sandboxed dll into the application appdomain As an extension of the previous point, you shouldn’t directly reference types or methods in the sandboxed dll from your application code. That loads the assembly into the fully-trusted appdomain, and from there code in the assembly could be executed. Instead, pull out methods you want the sandboxed dll to have into an interface or class in a partially-trusted assembly you control, and execute methods via that instead (similar to the example above with the IPlugin interface). If you need to have a look at the assembly before executing it in the sandbox, either examine the assembly using reflection from within the sandbox, or load the assembly into the Reflection-only context in the application’s appdomain. The code in assemblies in the reflection-only context can’t be executed, it can only be reflected upon, thus protecting your appdomain from malicious code. 3. Incorrectly asserting permissions You should only assert permissions when you are absolutely sure they’re safe. For example, this method allows a caller read-access to any file they call this method with, including your documents, any network shares, the C:\Windows directory, etc: [SecuritySafeCritical] public static string GetFileText(string filePath) { new FileIOPermission(FileIOPermissionAccess.Read, filePath).Assert(); return File.ReadAllText(filePath); } Be careful when asserting permissions, and ensure you’re not providing a loophole sandboxed dlls can use to gain access to things they shouldn’t be able to. Conclusion Hopefully, that’s given you an idea of some of the ways it’s possible to get past the .NET security system. As I said before, this post is not exhaustive, and you certainly shouldn’t base any security-critical applications on the contents of this blog post. What this series should help with is understanding the possibilities of the security system, and what all the security attributes and classes mean and what they are used for, if you were to use the security system in the future.

    Read the article

  • Is there a programming language with not a tree but tags idea behind OOP?

    - by kolupaev
    I'm thinking about tree structures, and I feel that I don't like them. It's like when you have a shop, then you try to put all products to tree-like catalog, and then you need to place one product to multiple categories, now you have multiple routing, bla-bla. I don't feel like everything in the world could be put to a tree. Instead, I like idea of tags. I would like to store everything with tags. With tags I could do much more. I can even simulate trees if I want. I want to have tag-based filesystem! But hey - modern OOP paradigm with inheritance is based on tree. I want to see how it is when you don't have such basement. Closest thing I found is mixins in some languages. Do you know what else is also about this ideas?

    Read the article

  • What are the basic skills a beginner JavaScript programmer should have?

    - by Sanford
    In NYC, we are working on creating a collaborative community programming environment and trying to segment out software engineers into differing buckets. At present, we are trying to define: Beginners Intermediates Advanced Experts (and/or Masters) Similar to an apprenticeship, you would need to demonstrate specific skills to achieve different levels. Right now, we have identified beginner programming skills as: Object - method, attributes, inheritance Variable - math, string, array, boolean - all are objects Basic arithmetic functions - precedence of functions String manipulation Looping - flow control Conditionals - boolean algebra This is a first attempt, and it is a challenge since we know the natural tension between programming and software engineering. How would you create such a skills-based ranking for JavaScript in this manner? For example, what would be the beginner JavaScript skills that you would need to have to advance to the intermediate training? And so on.

    Read the article

  • Any enlightenment for understanding Object Oriented Programming? [closed]

    - by ????
    I studied computer science near the end of 1980s, and wasn't taught OOP that formally. With Pascal or C, when I understand the top-down design of functions, and the idea of black box, then everything just seem to make sense, as if there is a "oh I get it!" -- some kind of totally getting it and enlightenment feeling. But with OOP, all I know was the mechanics: the class, instance, method, inheritance, polymorphism, encapsulation. It was like, I knew all the "this is how it is", but never had the feeling of "I totally get it", the enlightened feeling. Would somebody be able to describe it, or point to a chapter in some book or paper which talks about OOP so that the reader can feel: "I totally get it!" on OOP?

    Read the article

  • Mapping Help in the EDM Designer

    The mapping details window that displays the mappings between an entity and database table(s) is pretty straightforward. When you join two related tables in a Table Per Hierarchy inheritance things can get a little confusing when it comes to the mappings for inherited properties. But did you know that the Mapping Details window uses the Properties window to help? Here are two entities in a TPH hierarchy. Customer inherits Contact. Customer maps to a Customers table which uses ContactID as...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • Liskov substitution principle with abstract parent class

    - by Songo
    Does Liskov substitution principle apply to inheritance hierarchies where the parent is an abstract class the same way if the parent is a concrete class? The Wikipedia page list several conditions that have to be met before a hierarchy is deemed to be correct. However, I have read in a blog post that one way to make things easier to conform to LSP is to use abstract parent instead of a concrete class. How does the choice of the parent type (abstract vs concrete) impacts the LSP? Is it better to have an abstract base class whenever possible?

    Read the article

  • What are the basic skills a BEGINNING JavaScript programmer should have?

    - by Sanford
    In NYC, we are working on creating a collaborative community programming environment and trying to segment out software engineers into differing buckets. At present, we are trying to define: Beginners Intermediates Advanced Experts (and/or Masters) Similar to an apprenticeship, you would need to demonstrate specific skills to achieve different levels. Right now, we have identified Beginner programming skills as: Object - method, attributes, inheritance Variable - math, string, array, boolean - all are objects Basic arithmetic functions - precedence of functions String manipulation Looping - flow control Conditionals - boolean algebra This is a first attempt, and it is a challenge since we know the natural tension between programming and software engineering. How would you create such a skills-based ranking for JavaScript in this manner? For example, what would be the Beginner Javascript skills that you would need to have to advance to the Intermediate Training? And so on.

    Read the article

  • When to use mixins in Ruby

    - by Gilles
    I am wondering when to use mixins? I have read about them. Many authors compare them to interfaces, abstract classes, etc. Mixins are modules that are mixed-in and modules are a way to group similar methods, constants and classes together. I have seen examples where a module for math functions is created. It makes sense to group and reuse such functions but should I only mix these in a class if I am faced with an inheritance situation? Should I mix these in anytime I want to use them in a class? Should they be used exactly like interfaces in other languages or are there other subtleties?

    Read the article

  • UIView with IrrlichtScene - iOS

    - by user1459024
    i have a UIViewController in a Storyboard and want to draw a IrrlichtScene in this View Controller. My Code: WWSViewController.h #import <UIKit/UIKit.h> @interface WWSViewController : UIViewController { IBOutlet UILabel *errorLabel; } @end WWSViewController.mm #import "WWSViewController.h" #include "../../ressources/irrlicht/include/irrlicht.h" using namespace irr; using namespace core; using namespace scene; using namespace video; using namespace io; using namespace gui; @interface WWSViewController () @end @implementation WWSViewController -(void)awakeFromNib { errorLabel = [[UILabel alloc] init]; errorLabel.text = @""; IrrlichtDevice *device = createDevice( video::EDT_OGLES1, dimension2d<u32>(640, 480), 16, false, false, false, 0); /* Set the caption of the window to some nice text. Note that there is an 'L' in front of the string. The Irrlicht Engine uses wide character strings when displaying text. */ device->setWindowCaption(L"Hello World! - Irrlicht Engine Demo"); /* Get a pointer to the VideoDriver, the SceneManager and the graphical user interface environment, so that we do not always have to write device->getVideoDriver(), device->getSceneManager(), or device->getGUIEnvironment(). */ IVideoDriver* driver = device->getVideoDriver(); ISceneManager* smgr = device->getSceneManager(); IGUIEnvironment* guienv = device->getGUIEnvironment(); /* We add a hello world label to the window, using the GUI environment. The text is placed at the position (10,10) as top left corner and (260,22) as lower right corner. */ guienv->addStaticText(L"Hello World! This is the Irrlicht Software renderer!", rect<s32>(10,10,260,22), true); /* To show something interesting, we load a Quake 2 model and display it. We only have to get the Mesh from the Scene Manager with getMesh() and add a SceneNode to display the mesh with addAnimatedMeshSceneNode(). We check the return value of getMesh() to become aware of loading problems and other errors. Instead of writing the filename sydney.md2, it would also be possible to load a Maya object file (.obj), a complete Quake3 map (.bsp) or any other supported file format. By the way, that cool Quake 2 model called sydney was modelled by Brian Collins. */ IAnimatedMesh* mesh = smgr->getMesh("/Users/dbocksteger/Desktop/test/media/sydney.md2"); if (!mesh) { device->drop(); if (!errorLabel) { errorLabel = [[UILabel alloc] init]; } errorLabel.text = @"Konnte Mesh nicht laden."; return; } IAnimatedMeshSceneNode* node = smgr->addAnimatedMeshSceneNode( mesh ); /* To let the mesh look a little bit nicer, we change its material. We disable lighting because we do not have a dynamic light in here, and the mesh would be totally black otherwise. Then we set the frame loop, such that the predefined STAND animation is used. And last, we apply a texture to the mesh. Without it the mesh would be drawn using only a color. */ if (node) { node->setMaterialFlag(EMF_LIGHTING, false); node->setMD2Animation(scene::EMAT_STAND); node->setMaterialTexture( 0, driver->getTexture("/Users/dbocksteger/Desktop/test/media/sydney.bmp") ); } /* To look at the mesh, we place a camera into 3d space at the position (0, 30, -40). The camera looks from there to (0,5,0), which is approximately the place where our md2 model is. */ smgr->addCameraSceneNode(0, vector3df(0,30,-40), vector3df(0,5,0)); /* Ok, now we have set up the scene, lets draw everything: We run the device in a while() loop, until the device does not want to run any more. This would be when the user closes the window or presses ALT+F4 (or whatever keycode closes a window). */ while(device->run()) { /* Anything can be drawn between a beginScene() and an endScene() call. The beginScene() call clears the screen with a color and the depth buffer, if desired. Then we let the Scene Manager and the GUI Environment draw their content. With the endScene() call everything is presented on the screen. */ driver->beginScene(true, true, SColor(255,100,101,140)); smgr->drawAll(); guienv->drawAll(); driver->endScene(); } /* After we are done with the render loop, we have to delete the Irrlicht Device created before with createDevice(). In the Irrlicht Engine, you have to delete all objects you created with a method or function which starts with 'create'. The object is simply deleted by calling ->drop(). See the documentation at irr::IReferenceCounted::drop() for more information. */ device->drop(); } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. } - (void)viewDidUnload { [super viewDidUnload]; // Release any retained subviews of the main view. } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } @end Sadly the result is just a black View in the Simulator. :( Hope here is anyone who can explain me how i draw the scene in a UIView. Furthermore I'm getting this Error: Could not load sprite bank because the file does not exist: #DefaultFont How can i fix it ?

    Read the article

  • Why are interfaces useful?

    - by Pankaj Upadhyay
    I have been studying and coding in C# for some time now. But still, I can't figure the usefulness of Interfaces. They bring too little to the table. Other than providing the signatures of function, they do nothing. If I can remember the names and signature of the functions which are needed to be implemented, there is no need for them. They are there just to make sure that the said functions(in the interface) are implemented in the inheriting class. C# is a great language, but sometimes it gives you the feeling that first Microsoft creates the problem (not allowing multiple inheritance) and then provides the solution, which is rather a tedious one. That's my understanding which is based on limited coding experience. What's your take on interfaces? How often you make uses of them and what makes you do so?

    Read the article

  • Business Case for investing time developing Stubs and BizUnit Tests

    - by charlie.mott
    I was recently in a position where I had to justify why effort should be spent developing Stubbed Integration Tests for BizTalk solutions. These tests are usually developed using the BizUnit framework. I assumed that most seasoned BizTalk developers would consider this best practice. Even though Microsoft suggest use of BizUnit on MSDN, I've not found a single site listing the justifications for investing time writing stubs and BizUnit tests. Stubs Stubs should be developed to isolate your development team from external dependencies. This is described by Michael Stephenson here. Failing to do this can result in the following problems: In contract-first scenarios, the external system interface will have been defined.  But the interface may not have been setup or even developed yet for the BizTalk developers to work with. By the time you open the target location to see the data BizTalk has sent, it may have been swept away. If you are relying on the UI of the target system to see the data BizTalk has sent, what do you do if it fails to arrive? It may take time for the data to be processed or it may be scheduled to be processed later. Learning how to use the source\target systems and investigations into where things go wrong in these systems will slow down the BizTalk development effort. By the time the data is visible in a UI it may have undergone further transformations. In larger development teams working together, do you all use the same source and target instances. How do you know which data was created by whose tests? How do you know which event log error message are whose?  Another developer may have “cleaned up” your data. It is harder to write BizUnit tests that clean up the data\logs after each test run. What if your B2B partners' source or target system cannot support the sort of testing you want to do. They may not even have a development or test instance that you can work with. Their single test instance may be used by the SIT\UAT teams. There may be licencing costs of setting up an instances of the external system. The stubs I like to use are generic stubs that can accept\return any message type.  Usually I need to create one per protocol. They should be driven by BizUnit steps to: validates the data received; and select a response messages (or error response). Once built, they can be re-used for many integration tests and from project to project. I’m not saying that developers should never test against a real instance.  Every so often, you still need to connect to real developer or test instances of the source and target endpoints\services. The interface developers may ask you to send them some data to see if everything still works.  Or you might want some messages sent to BizTalk to get confidence that everything still works beyond BizTalk. Tests Automated “Stubbed Integration Tests” are usually built using the BizUnit framework. These facilitate testing of the entire integration process from source stub to target stub. It will ensure that all of the BizTalk components are configured together correctly to meet all the requirements. More fine grained unit testing of individual BizTalk components is still encouraged.  But BizUnit provides much the easiest way to test some components types (e.g. Orchestrations). Using BizUnit with the Behaviour Driven Development approach described by Mike Stephenson delivers the following benefits: source: http://biztalkbddsample.codeplex.com – Video 1. Requirements can be easily defined using Given/When/Then Requirements are close to the code so easier to manage as features and scenarios Requirements are defined in domain language The feature files can be used as part of the documentation The documentation is accurate to the build of code and can be published with a release The scenarios are effective to document the scenarios and are not over excessive The scenarios are maintained with the code There’s an abstraction between the intention and implementation of tests making them easier to understand The requirements drive the testing These same tests can also be used to drive load testing as described here. If you don't do this ... If you don't follow the above “Stubbed Integration Tests” approach, the developer will need to manually trigger the tests. This has the following risks: Developers are unlikely to check all the scenarios each time and all the expected conditions each time. After the developer leaves, these manual test steps may be lost. What test scenarios are there?  What test messages did they use for each scenario? There is no mechanism to prove adequate test coverage. A test team may attempt to automate integration test scenarios in a test environment through the triggering of tests from a source system UI. If this is a replacement for BizUnit tests, then this carries the following risks: It moves the tests downstream, so problems will be found later in the process. Testers may not check all the expected conditions within the BizTalk infrastructure such as: event logs, suspended messages, etc. These automated tests may also get in the way of manual tests run on these environments.

    Read the article

  • Plan variable and call dependencies

    - by Gerenuk
    I'd like to write down the design of my program to understand the dependencies and calls better. I know there are class diagrams which show inheritance and attribute variables. However I'd also like to document the input parameters to method functions and in particular which calls the methods function executes inside (e.g. on the input parameters). Also sometimes it might be useful to show how actual objects are connected (if there is a standard structure). This way I can have a better understanding of the modules and design before starting to program. Can you suggest a method to do this software design? It should be one-to-one to programming code structure so that I really notice all quirks beforehand (instead of high-level design where thing are hard to implement without further work). Maybe some special diagram or tool or a combination? It is static dependency and call design rather than time dependent execution monitoring. (I use Python if you have any specialized recommendations).

    Read the article

< Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >