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C# Cannot Cast Class To Interface


num long can // hold any value an int can hold, and more! Maintenance nightmare. 3. Why do I never get a mention at work? adding a Child to an Adult List.    people.Add(new Child()); } A Generic Covariant List Implementation As dire as this seems, not all is lost.

public static List Get(Guid companyID) { List prodList = new List(); ... Implicit casts do not require additional syntax, whereas explicit casts require cast operators. Cool! But why would someone want do the casting stated above? http://stackoverflow.com/questions/2640738/c-sharp-cannot-implicitly-convert-type-listproduct-to-listiproduct

C# Cannot Implicitly Convert Type To Interface

You can't just cast any type to any other arbitrary type successfully. Igor Ostrovsky says: September 9, 2009 at 2:01 pm Chad: Yes, you could have a list of non-generic nodes. c# generics share|improve this question edited Nov 27 '14 at 23:07 asked Nov 27 '14 at 22:39 AndySavage 1,118820 add a comment| 5 Answers 5 active oldest votes up vote 2

Make a common base class like StorableObject and inherit every storable thing from it. com... | Its looks like you are reading that C# book from O'Reilly as I have | that same example in my book. RegisterBlock block1Again = _blocks[0]; Nothing. _blocks is a list of RegisterBlock, so of course _blocks[0] is of type RegisterBlock. Cannot Implicitly Convert Type To T First Skills to Learn for Mountaineering Prepared for Yet Another Simple Rebus?

For example, you might have an integer variable that you need to pass to a method whose parameter is typed as double. Cannot Implicitly Convert Type Generic List To Generic List return new List(prodList.ToArray()); } share|improve this answer edited Apr 14 '10 at 20:48 answered Apr 14 '10 at 20:41 Nayan 2,0721226 add a comment| up vote -3 down vote Try this This documentation is archived and is not being maintained. In the scenario I encountered, I actually had a tree of them.

Summary .NET uses casting to jump from one interface to another in the same class. C# Cannot Implicitly Convert Type Generic Thus when you do this: IPrintable printableTicket = new Ticket(); printableTicket.Render(thePrinter); You have a guarantee that you are accessing the 'printable' behaviour of Ticket. However, Its seems like the author is just casting to IStorable as a test to see if doc implements the IStorable interface. What is the definition of "rare language"?

Cannot Implicitly Convert Type Generic List To Generic List

Follow-up: when operating on your tree of nodes, did you ever need to get to the Data? The most important thing is that it will help others that might google this up. –vidstige May 8 '12 at 7:01 add a comment| Your Answer draft saved draft discarded C# Cannot Implicitly Convert Type To Interface Join them; it only takes a minute: Sign up C# - Cannot implicitly convert type List to List up vote 51 down vote favorite 14 I have a project with all Cannot Implicitly Convert Type C# Related Sites Visual Studio Visual Studio Integrate VSIP Program Microsoft .NET Microsoft Azure Connect Forums Blog Facebook LinkedIn Stack Overflow Twitter Visual Studio Events YouTube Developer Resources Code samples Documentation Downloads

What is the definition of "rare language"? In the given example, yes you could do just that, but interfaces are designed, amongst other things, to allow commoin behaviour across hierarchies. Instead try using polymorphism, add the Log method to IApiDataWithProperties or some other interface and implement it in your types. ManipulateList(List list). Cannot Implicitly Convert Type List To List

Sami CHNITER says: November 10, 2012 at 5:07 pm Thank you for this great article Resources for Problem Solving,Discrete Maths,Data Structures,Algorithms and Cracking Interviews of comps like Microsoft,Facebook,Google,Amazon etc | Insight's An explicit conversion exists (are you missing a cast?) I think I'm missing some important condition that is required for this implicit cast to work, but I have not found what For transport one might pass a reference (variable) of type object. It's quick & easy.

For example, a variable of type long (8 byte integer) can store any value that an int (4 bytes on a 32-bit computer) can store. Cannot Implicitly Convert Type System Collections Generic Ienumerable Chad says: September 9, 2009 at 1:50 pm Very nice. However, there's no common ancestor between all of your "stored" classes: a StockItem and a Customer have nothing to do with each other, other than the fact that they can be

I changed one method signature and broke 25,000 other classes.

asked 4 years ago viewed 3153 times active 4 years ago Linked 13 Implementing nested generic Interfaces 0 Constraints on Type parameter(Type set to IComparable but unable to send Type as What now? Teach your central data-managing classes about each "storable" class. Cannot Implicitly Convert Type Void To System Eventhandler C# The code you write should work in all cases except that one –JaredPar Apr 13 '12 at 20:37 Post the class and interface definitions for your failing case (IComplexInterface

block1Again is of type RegisterBlock, which has a method AddRegister(IRegister), and DoubleWordRegister implements IRegister. ByteRegisterBlock : RegisterBlock This should get your code working, however, you do lose some flexibility. But in case you want it done this way.... Implicit implementation versus Explicit implementation0Is it possible to not implement a method inherited from an interface in C#?28C# internal interface with internal implementation2Cast from something Generic of implementing to something Generic

public static List Get(Guid companyID) { List myList = new List(); ... Animal a = g; // Explicit conversion is required to cast back // to derived type. Visual Basic (VB) .NET and C# cast differently. Player claims their wizard character knows everything (from books).

In a nutshell, generics cannot be covariant as it would allow illegal constructs.