Where is the main function?

Question

I'm trying to dust off my rusty C++ and learn DirectX

My first challenge is to modify a vanilla (just created off the template) Direct3D application and make it use XAML as in the sample:
http://code.msdn.microsoft.com/windowsapps/Metro-style-DirectX-18f98448

The problem is the vanilla D3D app has a main() function (fine!)

But the XAML app doesn't have a main(), somehow it directly "start" the app class!

How can that be?
Could I just add take all the 'app' file from another C++/WinRT project, hook them in, remove my main, and it will work?

Answer 1

I made a blank XAML app, copied the App[.xaml/.h/.cpp] and MainPage[.xaml/.h/.cpp], commented out the main() method (and a few other things) and tried to compile..

I get the following error:

---
error WMC1009: The type path of x:Class 'Tests.App' does not match the name of Windows metadata 'PaxGalactica.winmd' file
---

What can be the problem?

Me thing think it might be my App file should be called 'PaxGalactica.App' but there is already a class named 'PaxGalactica', I fear namespace and class name clashes.. going to try anyway!! :~

Answer 2

I removed the default PaxGalactica[.cpp/.h] and renamed my App and MainPage file to use the PaxGalactica namespace.

I did add 
#include "App.xaml.h"
in pch.h

when I compiled I get the error:
--
error WMC1002: x:Class type 'PaxGalatica.App' is not found in 'PaxGalactica' ???
--

I did check the XAML/.h/.cpp multiple time, they all have the namespace change...

what can be wrong??

Answer 3

looking at the .vcproj file I can see that I have an ItemGroup tag, with 
<ApplicationDefinition Include="App.xaml"/>
<Page Include="MainPage.xaml"/>

But I can't find anyway to set that in the UI (i.e. Solution Explorer and object properties window)

Is there a way other than editing the .vcxproj manually???

Anyway I edited the project manually (unload project, edit option appear) I made App.xaml an ApplicationDefinition (it was a Page)

And then.. .. I got plenty of new error.. did a "Rebuild"...

And it compiled and run!! :)

Answer 4

So where is the main function in XAML project?

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NEU_ShieldEdge

Answer 5

Luke, use the force!
There is main() but the App!!

Oops, sorry, tryed to answer Yoda style...

Anyway, there is no user defined main() but I suppose that tagging App.xaml as 'ApplicationDefinition' in the .vcxproj (instead of 'Page') will make the compiler generate a main() that will launch the application?!

Look in your XAML/C++ app folder for generated source code file (might be same in C#, haven't looked yet), I bet the App.g.cpp will contains a main()
(Can't check now, at work, without win8 machine!!)

Now that I think of it, on a normal WPF app there is no main either, the main() is in App.g.cs

Answer 6

There is a commented line before the App::App method in the App.xaml file which is generated when you use the Blank App (XAML) template:
// This is the first line of authored code executed, and as such is the logical equivalent of main() or WinMain().

So I guess this is what you try to find.

Answer 7

If you want a Direct3D+XAML app, I recommend starting with the "XAML Direct2D" app template and modify it as needed. The Direct2D XAML template has all the goop to get Direct3D and a SwapChainBackgroundPanel configured. Your "main" function will then be the DirectXPage constructor.

At least that's how I managed to get a D3D+XAML app up and running fairly quickly.

Answer 8

looking at the .vcproj file I can see that I have an ItemGroup tag, with 
<ApplicationDefinition Include="App.xaml"/>
<Page Include="MainPage.xaml"/>

But I can't find anyway to set that in the UI (i.e. Solution Explorer and object properties window)

Is there a way other than editing the .vcxproj manually???

Anyway I edited the project manually (unload project, edit option appear) I made App.xaml an ApplicationDefinition (it was a Page)

And then.. .. I got plenty of new error.. did a "Rebuild"...

And it compiled and run!! :)

you can set it in App.xaml's property panel.

just change the item type  to application difinition type

---

Yop

Answer 9

Ho.. it's a C++ project indeed, property are hidden in so many places! ^^
Indeed the property panel has it, thanks!
I was just not seeing it in the Property panel, where one can find that for a C# file!! ^^