Search Results

Search found 50973 results on 2039 pages for 'class names'.

Page 106/2039 | < Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >

  • Can't Use Generic C# Class in Using Statement

    - by Eric J.
    I'm trying to use a generic class in a using statement but the compiler can't seem to treat it as implementing IDisposable. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Objects; namespace Sandbox { public sealed class UnitOfWorkScope<T> where T : ObjectContext, IDisposable, new() { public void Dispose() { } } public class MyObjectContext : ObjectContext, IDisposable { public MyObjectContext() : base("DummyConnectionString") { } #region IDisposable Members void IDisposable.Dispose() { throw new NotImplementedException(); } #endregion } public class Consumer { public void DoSomething() { using (new UnitOfWorkScope<MyObjectContext>()) { } } } } Compiler error is: Error 1 'Sandbox.UnitOfWorkScope<Sandbox.MyObjectContext>': type used in a using statement must be implicitly convertible to 'System.IDisposable' I implemented IDisposable on UnitOfWorkScope (and to see if that was the problem, also on MyObjectContext). What am I missing?

    Read the article

  • C#: Problem trying to resolve a class when two namespaces are similar

    - by rally25rs
    I'm running into an issue where I can't make a reference to a class in a different namespace. I have 2 classes: namespace Foo { public class Class1 { ... } } namespace My.App.Foo { public class Class2 { public void SomeMethod() { var x = new Foo.Class1; // compile error! } } } The compile error is: The type or namespace name 'Class1' does not exist in the namespace 'My.App.Foo' In this situation, I can't seem to get Visual Studio to recognize that "Foo.Class1" refers to the first class. If I mouse-over "Foo", it shows that its trying to resolve that to "My.App.Foo.Class1" If I put the line: using Foo; at the top of the .cs file that contains Class2, then it also resolves that to "My.App.Foo". Is there some trick to referencing the right "Foo" namespace without just renaming the namespaces so they don't conflict? Both of these namespaces are in the same assembly.

    Read the article

  • C++ adding friend to a template class in order to typecast

    - by user1835359
    I'm currently reading "Effective C++" and there is a chapter that contains code similiar to this: template <typename T> class Num { public: Num(int n) { ... } }; template <typename T> Num<T> operator*(const Num<T>& lhs, const Num<T>& rhs) { ... } Num<int> n = 5 * Num<int>(10); The book says that this won't work (and indeed it doesn't) because you can't expect the compiler to use implicit typecasting to specialize a template. As a soluting it is suggested to use the "friend" syntax to define the function inside the class. //It works template <typename T> class Num { public: Num(int n) { ... } friend Num operator*(const Num& lhs, const Num& rhs) { ... } }; Num<int> n = 5 * Num<int>(10); And the book suggests to use this friend-declaration thing whenever I need implicit conversion to a template class type. And it all seems to make sense. But why can't I get the same example working with a common function, not an operator? template <typename T> class Num { public: Num(int n) { ... } friend void doFoo(const Num& lhs) { ... } }; doFoo(5); This time the compiler complaints that he can't find any 'doFoo' at all. And if i declare the doFoo outside the class, i get the reasonable mismatched types error. Seems like the "friend ..." part is just being ignored. So is there a problem with my understanding? What is the difference between a function and an operator in this case?

    Read the article

  • How to add a reference to my Web Service Proxy from a Custom Class

    - by coffeeaddict
    I'm creating a custom class to abstract out some of the repeated SOAP header work. I want to reference a Web Service Reference I just created in my custom class so I can create an instance of it. How do I reference it? Notice I said I am trying to reference a Web Service "reference" (right click in VS and I added a "Web Service Reference" not a "Web Service"). So I'm trying to create an instance of that Proxy class that was created in MyCustomClass.cs

    Read the article

  • PHP 'instanceof' failing with class constant

    - by Nathan Loding
    I'm working on a framework that I'm trying to type as strongly as I possibly can. (I'm working within PHP and taking some of the ideas that I like from C# and trying to utilize them within this framework.) I'm creating a Collection class that is a collection of domain entities/objects. It's kinda modeled after the List<T> object in .Net. I've run into an obstacle that is preventing me from typing this class. If I have a UserCollection, it should only allow User objects into it. If I have a PostCollection, it should only allow Post objects. All Collections in this framework need to have certain basic functions, such as add, remove, iterate. I created an interface, but found that I couldn't do the following: interface ICollection { public function add($obj) } class PostCollection implements ICollection { public function add(Post $obj) {} } This broke it's compliance with the interface. But I can't have the interface strongly typed because then all Collections are of the same type. So I attempted the following: interface ICollection { public function add($obj) } abstract class Collection implements ICollection { const type = 'null'; } class PostCollection { const type = 'Post'; public function add($obj) { if(!($obj instanceof self::type)) { throw new UhOhException(); } } } When I attempt to run this code, I get syntax error, unexpected T_STRING, expecting T_VARIABLE or '$' on the instanceof statement. A little research into the issue and it looks like the root of the cause is that $obj instanceof self is valid to test against the class. It appears that PHP doesn't process the entire self::type constant statement in the expression. Adding parentheses around the self::type variable threw an error regarding an unexpected '('. An obvious workaround is to not make the type variable a constant. The expression $obj instanceof $this->type works just fine (if $type is declared as a variable, of course). I'm hoping that there's a way to avoid that, as I'd like to define the value as a constant to avoid any possible change in the variable later. Any thoughts on how I can achieve this, or have I take PHP to it's limit in this regard? Is there a way of "escaping" or encapsulating self::this so that PHP won't die when processing it?

    Read the article

  • C# How can I return my base class in a webservice

    - by HenriM
    I have a class Car and a derived SportsCar: Car Something like this: public class Car { public int TopSpeed{ get; set; } } public class SportsCar : Car { public string GirlFriend { get; set; } } I have a webservice with methods returning Cars i.e: [WebMethod] public Car GetCar() { return new Car() { TopSpeed = 100 }; } It returns: <Car> <TopSpeed>100</TopSpeed> </Car> I have another method that also returns cars like this: [WebMethod] public Car GetMyCar() { Car mycar = new SportsCar() { GirlFriend = "JLo", TopSpeed = 300 }; return mycar; } It compiles fine and everything, but when invoking it I get: System.InvalidOperationException: There was an error generating the XML document. --- System.InvalidOperationException: The type wsBaseDerived.SportsCar was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically. I find it strange that it can't serialize this as a straight car, as mycar is a car. Adding XmlInclude on the WebMethod of ourse removes the error: [WebMethod] [XmlInclude(typeof(SportsCar))] public Car GetMyCar() { Car mycar = new SportsCar() { GirlFriend = "JLo", TopSpeed = 300 }; return mycar; } and it now returns: <Car xsi:type="SportsCar"> <TopSpeed>300</TopSpeed> <GirlFriend>JLo</GirlFriend> </Car> But I really want the base class returned, without the extra properties etc from the derived class. Is that at all possible without creating mappers etc? Please say yes ;)

    Read the article

  • Accessing main class stage event listener.

    - by Hwang
    I wanted to remove an event listener from main class stage, but i get the error 1120: Access of undefined property stage. How do I actually access the stage? custom class: import main; main.disableVcam(); main class: public static function disableVcam():void { trace("disable"); stage.removeEventListener(MouseEvent.MOUSE_MOVE, movevC); }

    Read the article

  • Why should structure names have a typedef?

    - by Jay
    I have seen source codes always having a typedef for a structure and using the same everywhere instead of using the structure name as "struct sname" etc directly? What is the reason behind this? Are there any advantages in doing this?

    Read the article

  • grabbing layer contents in a class

    - by Mike
    I have a custom UIImageView class that creates thumbnails (UIImageView) and each thumbnail has a label. The label is created by another class. The label class creates a UIImageView and a UITextView on top of it. This is the init object class' init method: - (id)initWithFrame:(CGRect)frame { if ([super initWithFrame:frame] == nil) { return nil; } CGRect myFrame = CGRectMake(0, 0, 100, 100); myLabel = [[myLabelClass alloc] initWithFrame: myFrame]; //myLabelClass is a UIImageView based class [myLabel setCenter:CGPointMake(50, 50)]; [self addSubview: myLabel]; return self; } So, I have this MAIN VIEW CONTROLLER | |___ UIImageView WITH LABEL | |____ label background (UIView) |____ UITEXTVIEW (text) Now I want to write the contents of all these 3 components to a quartz context. I need to write using drawInRect, because I need to write the full object to a precise location. I expected object.layer.contents to be the image equivalent to these 3 "layers" flattened, in other words, the object's image, the label background and the label text, as it would if I created these 3 objects in Photoshop and flatten the composition. I also expect object.myLabel.layer.contents to contains the rendered contents of the UITextView over the label background. The problem is that when I use UIImage *myImage = [UIImage imageWithCGImage:objecto.myLabel.layer.contents]; [myImage drawInRect:CGRectMake(0, 0, 100, 100)]; I get nothing. How can I obtain a "flattened" image resultant to the full object (including its subviews)? thanks

    Read the article

  • Change storyboard UIImageView to own class with backgroundcolor

    - by Thomas
    I want to draw the background image on my own, so I decided to implement a UIImageView class and connect it in the Storyboard. As first task I just want to set the backgroundcolor of the image on my own, but it's never shown. Image just stays blank. That's the class: class FirstBackgroundImage : UIImageView { required init(coder aDecoder: NSCoder) { super.init(coder: aDecoder) self.backgroundColor = UIColor.redColor() } override init() { super.init() self.backgroundColor = UIColor.redColor() } override required init(image: UIImage!) { super.init(image: image) self.backgroundColor = UIColor.redColor() } } That's how i connected it:

    Read the article

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

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

    Read the article

  • Why are my ActiveRecord class instance variables disappearing after the first request in development

    - by Paul C
    I have a class instance variable on one of my AR classes. I set its value at boot with an initializer and, after that, never touch it again except to read from it. In development mode, this value disappears after the first request to the web server. However, when running tests, using the console or running the production server this does not happen. # The AR class class Group < ActiveRecord::Base class << self attr_accessor :path end end # The initializer Group.path = File.join(RAILS_ROOT, "public", "etc") # First request in a view %p= Group.path #=> "/home/rails/app/public/etc" # Second request in a view %p= Group.path #=> nil Is there something about development mode that nukes instance variables from classes with each request? If so, is there a way to disable this for specific variables or classes?

    Read the article

  • Where to learn about VS debugger 'magic names'

    - by Gael Fraiteur
    If you've ever used Reflector, you probably noticed that the C# compiler generates types, methods, fields, and local variables, that deserve 'special' display by the debugger. For instance, local variables beginning with 'CS$' are not displayed to the user. There are other special naming conventions for closure types of anonymous methods, backing fields of automatic properties, and so on. My question: where to learn about these naming conventions? Does anyone know about some documentation? My objective is to make PostSharp 2.0 use the same conventions. Thank you!

    Read the article

  • How to dynamically set validation messages on properties with a class validation attribute

    - by Dan
    I'm writing Validation attribute that sits on the class but inspects the properties of the class. I want it to set a validation message on each of the properties it finds to be invalid. How do I do this? This is what I have got so far: [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = true)] public class LinkedFieldValidationAttribute : ValidationAttribute { private readonly string[] _properiesToValidate; public LinkedFieldValidationAttribute(params string[] properiesToValidate) { _properiesToValidate = properiesToValidate; } public override bool IsValid(object value) { PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(value); foreach (var propertyName in _properiesToValidate) { var propertyValue = properties.Find(propertyName, false).GetValue(value); //if value is invalid add message from base } //return validity } }

    Read the article

  • Any solution or programming tips for Inner class?

    - by huahsin68
    Hi, I'm having some toubt here. Hope you guys can share out some programming tips. Just curious to know whether is it a good programming practice if I do something like the code below. class Outer { public: class Inner { public: Inner() {} } Outer() {} }; I have been doing this for structure where I only want my structure to be expose to my class instead of global. But the case is different here, I am using a class now? Have you guys facing such a situation before? Very much appreciated on any advice from you ;)

    Read the article

  • Java: is Exception class thread-safe?

    - by Vilius Normantas
    As I understand, Java's Exception class is certainly not immutable (methods like initCause and setStackTrace give some clues about that). So is it at least thread-safe? Suppose one of my classes has a field like this: private final Exception myException; Can I safely expose this field to multiple threads? I'm not willing to discuss concrete cases where and why this situation could occur. My question is more about the principle: can I tell that a class which exposes field of Exception type is thread-safe? Another example: class CustomException extends Exception { ... } Is this class thread-safe?

    Read the article

  • Unique task queue task names only for active duration

    - by antony.trupe
    I want to guarantee that a task is not in a task queue more then once, so I generate a unique name based on it's payload. But, that task name is reserved for up to 7 days, which is not what I want; I only want it reserved for the duration the task is queued; it could be immediately re-queued. Once a Task with name N is written, any subsequent attempts to insert a Task named N will fail. Eventually (at least seven days after the task successfully executes), the task will be deleted and the name N can be reused. Is there a way to check if the named task is already in the queue then add it if it's not? Or a totally different approach?

    Read the article

  • Objective-C subclass and base class casting

    - by ryanjm.mp
    I'm going to create a base class that implements very similar functions for all of the subclasses. This was answered in a different question. But what I need to know now is if/how I can cast various functions (in the base class) to return the subclass object. This is both for a given function but also a function call in it. (I'm working with CoreData by the way) As a function within the base class (this is from a class that is going to become my subclass) +(Structure *)fetchStructureByID:(NSNumber *)structureID inContext:(NSManagedObjectContext *)managedObjectContext {...} And as a function call within a given function: Structure *newStructure = [Structure fetchStructureByID:[currentDictionary objectForKey:@"myId"]]; inContext:managedObjectContext]; Structure is one of my subclasses, so I need to rewrite both of these so that they are "generic" and can be applied to other subclasses (whoever is calling the function). How do I do that? Update: I just realized that in the second part there are actually two issues. You can't change [Structure fetch...] to [self fetch...] because it is a class method, not an instance method. How do I get around that too?

    Read the article

  • Sharing common class in wcf project

    - by Saint
    class MyCommonClass { //properties } This class should be accessible in service project wcf-client project the other for which they are references. In this common project I can't generate servicereferences. I think, I could don't generate MyCommonClass in ServiceReferences but how to mark class to be nonserializable? In properties there's IgnoreDataMemberAttribute. I tried also reuse MyCommonClass type located in common project, but it is still generated

    Read the article

  • Native SQL - How to set the schema and database names

    - by icelobber
    Im using Native SQL from ABAP language. The query to get data is something like this SELECT COUNT(ROWID) FROM <SCHEMANAME>.<TABLENAME>;@<DATABASENAME> INTO :localvariable I want to somehow set the schemaname and database name as default so that i do not need to use them in the SELECTs later. Then i can only use the table name in the SELECT. thanks !!

    Read the article

  • XDocument change all attribute names

    - by Dested
    I have an XDocument that looks similar to <root> <a> <b foo="1" bar="2" /> <b foo="3" bar="4" /> <b foo="5" bar="6" /> <b foo="7" bar="8" /> <b foo="9" bar="10" /> </a> </root> I wish to change the attribute foo to something else, and the attribute bar to something else. How can I easily do this? My current version (below) stack overflows with large documents, and has an awful smell to it. string dd=LoadedXDocument.ToString(); foreach (var s in AttributeReplacements) dd = dd.Replace(s.Old+"=", s.New+"=");

    Read the article

  • Graph call "/me/friends" doesn't contain names if called from a testuser

    - by Marc
    When I log into Facebook with my account and call the Graph API with /me/friends it returns an array like this: [ {id: "6868...", name: "John Smith"}, {id: "7531...", name: "Diane Smith"}, ... ] But if I'm logged in with a Facebook testuser and do the same call I get an array like this: [ {id: "100002927..."}, {id: "100003151..."}, ... ] So I'm missing the name property. Bug? Or did I some mistake? I'm using the JS SDK, but I think that doesn't matter.

    Read the article

  • SSRS Report Manager Report names

    - by Adam
    Is it possible to have SSRS's Report Manager display a report name that is not the .RDL file name? I.E. I have a Report .RDL named "MyReportAboutSomeImportantStuff.RDL" but I want the Report Manager to display this user friendly as "My Report About Some Important Stuff."

    Read the article

  • are these css classes names good?

    - by metal-gear-solid
    See section /* Common Classes */ of this page. http://webdesign.about.com/od/css/a/master_stylesht_2.htm are these css classes good, to use in any project? in terms of semantic? /* Common Classes */ .clear { clear: both; } .floatLeft { float: left; } .floatRight { float: right; } .textLeft { text-align: left; } .textRight { text-align: right; } .textCenter { text-align: center; } .textJustify { text-align: justify; } .blockCenter { display: block; margin-left: auto; margin-right: auto; } /* remember to set width */ .bold { font-weight: bold; } .italic { font-style: italic; } .underline { text-decoration: underline; } .noindent { margin-left: 0; padding-left: 0; } .nomargin { margin: 0; } .nopadding { padding: 0; } .nobullet { list-style: none; list-style-image: none; }

    Read the article

< Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >