Call C# method from C++ in cocos2d-x (Windows phone)

If you code on windows phone with cocos2d-x maybe sometime you need to call method from C# like share link facebook, email, in-app purchase, ads,.... So that I write this tutorial to help someone who want to call C# method from C++. Now let do it!

- First you create a new project and open wp8 project (I’m using cocos2d-x 3.4).

If you have error like this:

You need do add cocos2d namespace by : using cocos2d; anh then go BUILD -> Clean Solution

Note: On cocos2d-x 3.3 and lower namespace PhoneDirect3DxamlAppComponent was changed to cocos2d.I’m using cocos 3.4 so I work on name space cocos2d, if you work on lower version name space is PhoneDirect3DxamlAppComponent.

- Open HelloWorldScene.h we will do something in here:

You know, in cocos2d-x 3.4 C# and C++ use namespace cocos2d together and we will do in this namespace.

Well, I will create an Interface class and a ref class like this above class HelloWorld

namespace cocos2d
{
       [Windows::Foundation::Metadata::WebHostHidden]
       public interface class ICallback
       {
       public:
               virtual void CallFunc(Platform::String ^mess);
       };

       public ref class PlatformCenter sealed
       {
       public:
              PlatformCenter(void);
              static void setCallback(ICallback ^callback);
              static void callFunc(Platform::String^ s);
       };    
};

Interface class ICallback will be used on C# and class PlatformCenter will be used on C++ to call callFunc() from C#.

We need 2 static method:

static void setCallback(ICallback ^callback);

this use to selCallback in C# like delegate.

static void callFunc(Platform::String^ s);

this use to call callFunc() from C++ with String input.

- Open HelloWorldScene.cpp and we will code CallFunc method:

Add this code above HelloWorld class

namespace cocos2d
{
       ICallback ^callBack = nullptr;

       PlatformCenter::PlatformCenter()
       {

       }

       void PlatformCenter::callFunc(Platform::String ^s)
       {
              callBack->CallFunc(s);
       }

       void PlatformCenter::setCallback(ICallback ^callback)
       {
              callBack = callback;
       }
};

- Next we leave to MainPage.xaml.cs on C#

On name space cocos2d (cocos2d-x 3.3 and lower namespace PhoneDirect3DxamlAppComponent)

Create new class inherit PhoneApplicationPage class and ICallback interface. If it doesn’t work, go to BUILD menu and Rebuild Solution

public class CSCallBack : PhoneApplicationPage, ICallback
    {
        public CSCallBack()
        {
            PlatformCenter.setCallback(this);
        }

        public void CallFunc(String s)
        {
            this.Dispatcher.BeginInvoke(() =>
            {
                MessageBox.Show(s);
                //MessageBox will show string input from C++.
            });
        }
    }

Then, go to MainPage class create new instance of CSCallBack in MainPage Constructor

public MainPage()
        {
            InitializeComponent();
            CSCallBack cs = new CSCallBack();
            …... //some codes under
        }

- Go back HelloWorldScene.cpp we will send string from C++

define new void method in class HelloWorld (in HelloWorldScene.h)

void CallCSharp();

next we code in this method:

void HelloWorld::CallCSharp()
{
       std::string s ="Text from C++ -> Welcome REDzz - Crazyland";
       std::wstring wstr;
       wstr.assign(s.begin(), s.end());
       PlatformCenter::callFunc(ref new Platform::String(wstr.c_str()));
}

In this method:

First we will create a string then convert it to wstring and then to Platform::String

Now run and enjoy winning ^^!.

Download Project on Github:

https://github.com/loctho1995/Crazyland-Tutorial

Well, maybe you need to read more infomation about:

[Windows::Foundation::Metadata::WebHostHidden]

http://stackoverflow.com/questions/12713143/why-is-windowsfoundationmetadatawebhosthidden-added-by-default-in-custom

https://msdn.microsoft.com/en-us/library/windows/apps/windows.foundation.metadata.webhosthiddenattribute

ref class and structs

https://msdn.microsoft.com/en-us/library/hh699870.aspx

https://msdn.microsoft.com/en-us/library/0w2w91tf.aspx

Platform::String

https://msdn.microsoft.com/en-us/library/hh755812.aspx

https://msdn.microsoft.com/en-us/library/hh699879.aspx

If you have problem when do this tutorial please leave a comment I will try my best to help you ^^. Finally, this post can have some mistake from me (like wrong typing, wrong grammar, ...) please tell me if you see it ^^ Thanks.

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