The largest change in the Windows Phone 8 SDK was the addition of support for native code. As a .NET developer you may be turned off by the idea of returning to an unmanaged language, but with the Windows Runtime (WinRT) API, Component Extensions (C++/CX) and C++ 11 support, native development for Windows Phone 8 may be less intimidating then you would think. In this talk I’ll go over some of the features of C++/CX and show examples of using the native WinRT API in a Windows Phone 8 app.

1. WAY AHEAD™
Native Development for Windows Phone
The Windows Runtime API and Modern C++

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»Senior Software Engineer at ALK Technologies
»Led development effort to bring CoPilot GPS
navigation app to Windows Phone 8
» #4 Free Navigation App in Window Phone store
»Windows Phone Dev by day and night
» Released 6 of my own apps to Windows Phone store
»Blog: www.robwirving.com
»Twitter: @robwirving
Rob Irving

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»History of Native on Windows Phone
»Why use Native?
»C++ 11
»Windows Runtime (WinRT)
»Component Extensions (C++/CX)
»Options in Visual Studio
»Sample Code
»Q & A
Agenda

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»Lack of Native Development on WP7 hurt the
platform
» Lack of high-end games available on other platforms
» More difficult/impossible to port existing apps from
other platforms
»Support for Native Development is the single
largest change in the WP8 SDK
»Native Gaming and Middleware products
» Unity 3D, Havok, Cocos 2D, etc.
History of Native on Windows Phone

5. WAY AHEAD™
Why use Native?

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»Reusability
» Existing code that you don’t want to rewrite
» Use of existing 3rd party libraries (SQLite)
»Portability
» Share code between Windows, iOS and Android
» Write once, use it everywhere
Why use Native?

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»Game development with high-end graphics
» Direct3D on Windows and Windows Phone
» OpenGL on iOS and Android
»Performance
» Should not be viewed as the main reason to use C++
» Performance can be better using Native, but is often
exaggerated
Why use Native?

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»Portability & Reusability in action
» ~1,000 Lines of C# for WP8
» ~7,000 Lines of new C++ and C++/CX
» ~800,000 Lines of existing C++ code
»~99% shared code between
Windows Phone, iOS and Android!
CoPilot GPS – Native Case Study

9. WAY AHEAD™
A brief introduction to Modern C++
C++ 11

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1979
1983
1998 2011
History of C++
C++ began as an
enhancement
to C at Bell Labs
Originally named
‘C with Classes’
Renamed to C++
C++ ISO committee
defined C++ 98
No significant changes
to C++ for 13 years
C++ ISO committee
defined C++ 11
New features heavily
influenced by managed
languages like .NET

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»Type inference (auto)
» Avoid explicitly declaring the type of a variable
» Similar to .NET ‘var’ keyword
»Lambdas
» Anonymous inline functions
C++ 11 Features
int num1 = 10;
double num2 = 2.5
auto num3 = num1 / num2;
std::vector<CityLocation> cities;
std::sort(begin(cities), end(cities), [](CityLocation a, CityLocation b)
{
return a.distance < b.distance;
});

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»Strongly type enums
»Foreach-ish loop
C++ 11 Features
int numbers[] = {0, 1, 2, 3, 4, 5};
int sum = 0;
for(int& number : numbers)
{
sum += number;
}
enum class Fruit
{
Apple,
Banana,
Orange
};
if(meal.Fruit == Fruit::Banana)
// do Banana stuff
int fruitAbomination = Apple + Orange; // ERROR - Can’t do this anymore

13. WAY AHEAD™
Windows Runtime API

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»Shared API between Windows Phone 8 and
Windows Store Apps
» Overlaps much of the existing Windows Phone .NET
API
» Not all APIs are available for both
» ~11,000 Windows Runtime
» ~2,800 for both
» ~600 Windows Phone Runtime
Windows Runtime API (WinRT)

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»API is a COM-based Native API
»Accessible from C#, VB.NET and Component
Extensions (C++/CX)
» Also Javascript on Windows 8
»API definitions in Windows Metadata (.winmd)
files
» Similar format to .NET API definitions
Windows Runtime API (WinRT)

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»Native / Managed Interop
» WinRT is the only supported method of interop
»The most painful parts of Native /Managed
interop are gone with Windows Runtime
» No P/Invoke
» No Marshalling
Native Interop is easy with WinRT

17. WAY AHEAD™
Component Extensions (C++/CX)

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»Syntax and Library abstractions to interact with
COM based WinRT API
»Much easier to develop for compared to old
COM programming
Component Extensions (C++/CX)

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»Syntactically similar to C++/CLI
» ‘ref’ and ‘sealed’ classes
» Reference pointers or ‘hats’ ^
Component Extensions (C++/CX)
public ref class Foo sealed
{
};
Foo^ foo = ref new Foo();

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»Differences from C++/CLI
» No managed CLR
» No Garbage Collection, ref counted objects instead
» ref new instead of gcnew
» Pure C++ classes allowed in C++/CX classes
» Global ref ptr’s allowed
Component Extensions (C++/CX)

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»Properties
» No value keyword
» Can’t have public get, private set
Component Extensions (C++/CX)
public ref class Foobar sealed
{
public:
property int Foo; // automatic/trivial property
property int Bar
{
int get() { return _bar; }
void set(int newBar)
{
if(newBar > 0)
_bar = newBar;
}
}
private:
int _bar;
};

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»Events
» Very similar to .NET events
» Unsubscribe using token
Component Extensions (C++/CX)
MyClass::MyClass()
{
geoLocator = ref new Geolocator();
// subscribe
eventToken = geoLocator->PositionChanged +=
ref new TypedEventHandler<Geolocator^, PositionChangedEventArgs^>(this, &MyClass::OnPosChanged);
}
MyClass::~MyClass()
{
// unsubscribe
geoLocator->PositionChanged -= eventToken;
}
void MyClass::OnPosChanged(Geolocator^ geoLocator, PositionChangedEventArgs^ args)
{
auto geoPos = args->Position->Coordinate;
}

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»XAML with Direct 3D
Options in Visual Studio

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»Several Native Projects available
Options in Visual Studio

25. WAY AHEAD™
Visual Studio Demo

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Additional Resources
Windows Phone 8 Development Internals
(Whitchapel, McKenna)
http://amzn.to/1a2989c
Modern C++ and Windows Store Apps
(Poduri)
http://amzn.to/GEW6Y4

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»Channel 9 – channel9.msdn.com
» Build 2012 Sessions
channel9.msdn.com/Events/Build/2012/
» Build 2013 Sessions
channel9.msdn.com/Events/Build/2013/
» Going Native
channel9.msdn.com/Shows/C9-GoingNative
»C++ 11 Features in Visual C++ 11
blogs.msdn.com/b/vcblog/archive/2011/09/12/10209291.aspx
Additional Resources

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»Questions & Answers
»Slides will be posted to blog: robwirving.com
Thank You!