第三方库中的MonoTouch绑定通知

Question

I am working to create bindings for IDTech CC swipers. I have been banging my head against this for a while. I am stuck on how to subscribe to events that are raised by the 3rd party library. Specifically, I need to know when a card swipe has occured.

//Notification identifiers used with NSNotificationCenter
//physical attachment related
extern NSString * const uniMagAttachmentNotification;
extern NSString * const uniMagDetachmentNotification;
//connection related
extern NSString * const uniMagInsufficientPowerNotification;
extern NSString * const uniMagPoweringNotification;
extern NSString * const uniMagTimeoutNotification;
extern NSString * const uniMagDidConnectNotification;
extern NSString * const uniMagDidDisconnectNotification;
//swipe related
extern NSString * const uniMagSwipeNotification;
extern NSString * const uniMagTimeoutSwipeNotification;
extern NSString * const uniMagDataProcessingNotification;
extern NSString * const uniMagInvalidSwipeNotification;
extern NSString * const uniMagDidReceiveDataNotification;
//command related
extern NSString * const uniMagCmdSendingNotification;
extern NSString * const uniMagCommandTimeoutNotification;
extern NSString * const uniMagDidReceiveCmdNotification;
//misc
extern NSString * const uniMagSystemMessageNotification;

The documentation says this should work:

    [Notification]
    [Field ("uniMagAttachmentNotification")]
    NSString uniMagAttachmentNotification { get; }

It doesn't compile.

obj/Debug/ios/magTechBinding/uniMag.g.cs(637,95): error CS0117: `MonoTouch.Constants' does not contain a definition for `magTechBindingLibrary'
obj/Debug/ios/magTechBinding/uniMag.g.cs(637,77): error CS1502: The best overloaded method match for `MonoTouch.ObjCRuntime.Dlfcn.dlopen(string, int)' has some invalid arguments
obj/Debug/ios/magTechBinding/uniMag.g.cs(637,77): error CS1503: Argument `#1' cannot convert `object' expression to type `string'

Any thoughts or help would be greatly appreciated!

Answer 1

Try:

[Field ("uniMagAttachmentNotification", "__Internal")]

The second parameter tells inside which library to look for the field. Without one the generator presume you'll have a constant ready for it.

Now since you'll be linking the 3rd party static (.a) library it will become part of the final executable. That's why __Internal must be used as the library name (it means looks inside the main executable).