C++/cx easy to get started

C++/CX Introduction

C++/CX is a native development language provided by Microsoft for Windows Store and the Windows Phone Store app developer, which is a extension of C + +, which means that it is compatible with C + +.

As you can see from the name, C++/CX contains C + + and the extension of C + +. The x representation of CX is similar to x in technologies such as DirectX and ActiveX, and represents a variety of technologies in C + + extension.

C++/CX is not only compatible with ISO C + +, but also STL compliant.

For native developers who like C + +, it's helpful to understand some of the c++/cx's understanding of the program in Windows Store app development or the Windows Phone Store app development process.

It is important to emphasize that C++/CX is just a wrapper, this wrapper can be very thin, that is to say, for developers, the majority of the application code can be standard C + +, only a very small part of the C++/CX syntax.

Reasons for using C++/CX and native development

C++/CX can interact with XAML, and can interact with other languages such as C # and VB, while standard C + + is not available. So when we use C + + development, and we need to interact with XAML or other languages, we need to use C++/CX. C++/CX compatible with C + +.

In a Windows development environment, some developers might prefer C #, or Html5+js. Also some like developers like native development, generally have the following reasons

1. Need for more efficient procedures

2. There is an existing C++/C code

3. More familiar with C + + development

4. You need to use DirectX or other APIs that only support C + +. Currently, DirectX development can only use C + + in the Windows Store and the Windows Phone store.

Common C + + 11 syntax

While there are many new features in C + + 11, the following are inevitably encountered when developing Windows Store apps:

1. Auto keyword, as follows: Auto has the function of type deduction here, Obja is automatically judged as the ClassA type.

Auto Obja = new ClassA ();

2. Lamda expression. Java and C # developers may be familiar with this syntax, but many C + + developers are not familiar with it.

3. Null pointer nullptr. In C + + 11, nullptr is a reserved keyword that already exists to represent a null pointer, without requiring a developer macro to define a null representation of a null pointer.

4. Various smart pointers such as Unique_ptr, shared_ptr and weak_ptr

Refer to the following link for the C + + 11 standard

Http://msdn.microsoft.com/en-us/library/hh279654.aspx

Http://www.codeproject.com/Articles/570638/Ten-Cplusplus11-Features-Every-Cplusplus-Developer

Syntax that must be used for C++/CX

1. Ref new. For Windows RT types, you must use ref new to generate the object, as follows. Ref indicates that there is a reference count, that is, C++/CX automatically manages the life cycle of objects by reference counting.

Auto Calendara = ref new Calendar;

Calendara, Settonow (); Invoke with pointer method

2. Ref class for a custom class, if you also want to automatically use reference counting to manage objects, add ref before the class definition as follows:

ref class Classexample {

...

};

3. ^. The representation of a pointer with a reference count. As follows:

Calendar^ Calendarb = ref new Calendar;

Calendarb->settonow ();

(*calendarb).  Settonow (); This is used in the same way as standard C + +, with *

As long as you understand ref and ^, you will be able to read and use the C++/CX code using ISO C + + 11. Check out the unfamiliar places.

Ref pointers Reviews

The two points of ref and ^ should be the biggest changes in c++/cx relative to standard C + +, which is not used by many standard C + + developers when they first see them. Although standard C + + also has smart pointers, the ref pointer in C++/CX has some highlights, such as the size of the ref pointer is the same as the size of a normal pointer (raw pointer), or it can be used with the same cast as standard C + +. As follows. From these two points, C++/cx's pointers seem to be closer to the C + + pointers we learned years ago.

refchild^ Refchild = ref new Refchild ();

refparent^ pparent = Refchild; //Initialize the parent class pointer with the subclass object

Try

{

refchild^ pchild = dynamic_cast<refchild^> (pparent);

Pchild->methodfromchild ();

}

catch (const std::bad_cast& e)

{

Cerr << e.what () << ' \ n ';

Cerr << "This type is not a subclass \ n";

}//Type-safe, natural pointers

C++/CX Reference Counting Principle Example:

{

Auto P1 = ref new Refparent (); the reference count of the//parent object is added to 1, which becomes 1. (Parent AddRef ())

Auto P2 = ref new Refchild (); //child object reference count plus 1, becomes 1 (Child AddRef ())

The parent object reference count is reduced by 1, and the parent object is released. (Parent Release)

Child object reference count plus 1, becomes 2 (Child AddRef ())

P1 = p2;

Reference count of child object minus 1, becomes 1 (Child Release ())

P1 = nullptr;

}//Child Release ()

Say so much first, welcome the exchange of guidance.

C++/cx easy to get started