how to create binding for an extern declaration

问题:

I'm trying to create a binding for an iOS library.

When creating a native app with this library, it requires to include a .h header file which declares a global ApplicationKey variable like this:

extern const unsigned char ApplicationKey[];

and you are supposed to implement it

const unsigned char ApplicationKey[] = {0x11, ... };

Now, when creating the Xamarin binding for this library, the header file is mapped by Objective Sharpie to

partial interface Constants
{
    // extern const unsigned char [] ApplicationKey;
    [Field ("ApplicationKey")]
    byte[] ApplicationKey { get; }
}

How to change it to be able to set ApplicationKey from C# code?

回答1:

Your ApiDefination.cs file should be like this

[BaseType (typeof(NSObject))]
    public partial interface Constants
    {
        [Export ("ApplicationKey")]
        TypeOfProperyInNativeCode ApplicationKey { get; set; }
    }

in order to access this property create instance of Constant Class of binding project and access like this

Binding.Constant cons= new Binding.Constant();
cons.ApplicationKey  =value;

For better understanding you can follow this link http://developer.xamarin.com/guides/ios/advanced_topics/binding_objective-c/Walkthrough_Binding_objective-c_library/