asp.net display barcode font INHERITAN CE in Visual C#.NET

Paint ECC200 in Visual C#.NET INHERITAN CE

CHAPTER 8 INHERITAN CE
DataMatrix Creation In C#
Using Barcode maker for .NET Control to generate, create Data Matrix ECC200 image in VS .NET applications.
www.OnBarcode.com
Decoding ECC200 In Visual C#
Using Barcode decoder for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
your C++/CLI programs (as long you re not using safe mode) if your design requires it. You just can t have it be a managed type. Another difference between inheritance in C++/CLI and classic C++ is the absence of private or protected inheritance. Inheritance is always public, but the public keyword is optional. Private inheritance was sometimes used in classic C++ to inherit an implementation: it is intended to model the has-a relationship, which can also be modeled by containing the type as a field. It is sometimes said that value types cannot participate in inheritance. This is not strictly true; value types can implement interfaces, but not inherit from other value classes or reference types. Value types do inherit from System::ValueType, although they have to be boxed in order to realize this inheritance relationship. Unboxed value types have no virtual function table with which to participate in polymorphism.
Barcode Encoder In Visual C#.NET
Using Barcode creation for .NET Control to generate, create Barcode image in .NET framework applications.
www.OnBarcode.com
QR Code JIS X 0510 Maker In Visual C#
Using Barcode drawer for .NET Control to generate, create QR Code image in VS .NET applications.
www.OnBarcode.com
Name Collisions in Inheritance Hierarchies
EAN13 Generator In Visual C#.NET
Using Barcode maker for .NET framework Control to generate, create EAN 13 image in Visual Studio .NET applications.
www.OnBarcode.com
Data Matrix Drawer In C#
Using Barcode printer for Visual Studio .NET Control to generate, create DataMatrix image in VS .NET applications.
www.OnBarcode.com
C++/CLI provides some additional ways to control whether functions in a derived class override a base class function, or whether they simply provide a new function that hides the base class function. The question is, Why The answer has to do with real-world problems associated with updating the base class to a new version. Library vendors often add new functions, including virtual functions, to their base classes to support new features. Consumers of these libraries generally have their own classes that use the library s base classes. It s possible that method name conflicts arise between the library consumer s derived classes and the library vendor s base classes. To make this a little more concrete, let s say we re creating an adventure game in which we have a player up against numerous monsters. Our game is extensible, so we ship our game library, and developers create their own monster types by inheriting from the Monster type in our library. We also have other objects in the game other than monsters, such as weapons, armor, and the like (all represented by an Item class) and tiles on the game map. So, our hierarchy looks like Listing 8-1. Listing 8-1. The Monster Hierarchy // game_library.cpp public ref class GameObject { }; public ref class Monster : GameObject { }; public ref class MapTile : GameObject { };
PDF 417 Generator In Visual C#
Using Barcode printer for .NET framework Control to generate, create PDF 417 image in Visual Studio .NET applications.
www.OnBarcode.com
Uniform Symbology Specification ITF Encoder In C#.NET
Using Barcode printer for .NET framework Control to generate, create Uniform Symbology Specification ITF image in VS .NET applications.
www.OnBarcode.com
C HA PTER 8 INHERITA NCE
Scanning DataMatrix In .NET
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Data Matrix ECC200 Encoder In Visual Studio .NET
Using Barcode creator for Reporting Service Control to generate, create ECC200 image in Reporting Service applications.
www.OnBarcode.com
public ref class Item : GameObject { }; To explore versioning issues, suppose a client of this game library has a Scroll class (see Listing 8-2) representing magic spells written out on a scroll. This class supports a Read method that invokes a spell. Listing 8-2. A Class for Magic Spells // client_game.cpp #using "game_library.dll" ref class Scroll : Item { public: void Read() { /* read the scroll and invoke the spell */ } }; Let s say that we are shipping a new version of our library, and we add functionality to read and write GameObject instances from a file. So we add Read and Write methods, as in Listing 8-3. Listing 8-3. New Functionality for Game Objects public ref class GameObject { public: void Initialize(); virtual void Read() { /* read data from file */ } virtual void Write() { /* write data to file */ } }; They re virtual so that derived classes can read and write their own information, if needed. The question is, What happens when the user upgrades to the new version In C++, what might happen is that the virtual Read method for reading the scroll would silently override the Read method to read from a file. Then, at runtime, when we try to read data (as in Listing 8-4), the Read function in the Scroll class gets called and the game character casts a spell not what was intended at all. Listing 8-4. Reading with an Unintended Method void GameObject::Initialize() { if (reading_from_file) { Read(); // Oops! Scroll method called. } // ... }
Make Code 39 In None
Using Barcode printer for Microsoft Excel Control to generate, create Code39 image in Microsoft Excel applications.
www.OnBarcode.com
Recognizing Barcode In VB.NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Scanning QR Code 2d Barcode In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
PDF417 Creation In None
Using Barcode maker for Font Control to generate, create PDF-417 2d barcode image in Font applications.
www.OnBarcode.com
QR Code 2d Barcode Reader In VB.NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Encode EAN-13 In None
Using Barcode generator for Font Control to generate, create EAN 13 image in Font applications.
www.OnBarcode.com
Read PDF-417 2d Barcode In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Making QR Code In VS .NET
Using Barcode drawer for Reporting Service Control to generate, create QR Code JIS X 0510 image in Reporting Service applications.
www.OnBarcode.com
Decode UPC Code In VB.NET
Using Barcode reader for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
GTIN - 128 Maker In None
Using Barcode generator for Microsoft Word Control to generate, create USS-128 image in Office Word applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.