System.MemberAccessException调用SktClassFactory.CreateScanObject ()；在SocketScan Xamarin iOS绑定项目中

Question

我正在创建一个使用SocketScan的SocketScan SDK的Xamarin应用程序。创建一个绑定项目，以将静态库转换为dll。但是无法使用ISktScanObject ()方法创建SktClassFactory.CreateScanObject实例。由于System.MemberAccessException，实例没有被完全创建。请看下面的代码

// A 1:1 of ApiHelper's Objective-C open: method
public void Open ()
{
    _deviceInfoList.Clear ();

    if (_noDeviceText != null) {
        _deviceInfoList.Add (_noDeviceText, _noDeviceText);
    }

    if (_scanObjectReceived != null) {
        SktClassFactory.ReleaseScanObject (_scanObjectReceived);
    }
    _scanObjectReceived = SktClassFactory.CreateScanObject (); //Two properties inside _scanObjectReceived are not getting created due to System.MemberAccessException. 

    Task.Run (() => InitializeScanAPIThread ());

    _scanApiOpen = true;
}

下面是我在调试_scanObjectReceived对象时在_scanObjectReceived = SktClassFactory.CreateScanObject ()行之后收到的异常消息；

1. Msg System.MemberAccessException:无法创建ScanAPI.ISktScanMsg的实例，因为它是一个抽象类
2. 属性System.MemberAccessException:无法创建ScanAPI.SktScanProperty的实例，因为它是一个抽象类

绑定项目中ISktScanObject接口的ISktScanObject如下：

[Protocol, Model]    
interface ISktScanObject {}

// @protocol ISktScanObject
[Protocol, Model]
[BaseType (typeof (NSObject))]
interface SktScanObject : ISktScanObject
{
    // @required -(id<ISktScanMsg>)Msg;
    [Abstract]
    [Export ("Msg")]
    ISktScanMsg Msg { get; }

    // @required -(id<ISktScanProperty>)Property;
    [Abstract]
    [Export ("Property")]
    SktScanProperty Property { get; }
} 

绑定项目中SktClassFactory接口的SktClassFactory如下：

[BaseType (typeof(NSObject))]
interface SktClassFactory
{
    // +(id<ISktScanObject>)createScanObject;
    [Static]
    [Export ("createScanObject")]
    ISktScanObject CreateScanObject ();

    // +(void)releaseScanObject:(id<ISktScanObject>)scanObj;
    [Static]
    [Export ("releaseScanObject:")]
    void ReleaseScanObject (ISktScanObject scanObj);

    // +(id<ISktScanApi>)createScanApiInstance;
    [Static]
    [Export ("createScanApiInstance")]
    ISktScanApi CreateScanApiInstance ();

    // +(void)releaseScanApiInstance:(id<ISktScanApi>)scanApi;
    [Static]
    [Export ("releaseScanApiInstance:")]
    void ReleaseScanApiInstance (ISktScanApi scanApi);

    // +(id<ISktScanDevice>)createDeviceInstance:(id<ISktScanApi>)scanApi;
    [Static]
    [Export ("createDeviceInstance:")]
    ISktScanDevice CreateDeviceInstance (ISktScanApi scanApi);

    // +(void)releaseDeviceInstance:(id<ISktScanDevice>)deviceInstance;
    [Static]
    [Export ("releaseDeviceInstance:")]
    void ReleaseDeviceInstance (ISktScanDevice deviceInstance);
} 

正确实例化_scanObjectReceived对象需要做些什么。提前谢谢。

Answer 1

这可能早就应该执行了，但是使用当前的API，我能够创建一个iOS绑定并使用以下方法调用ISktScanObject & ISktScanApi：

ScanObject = SktClassFactory.CreateScanObject;
ScanApi = SktClassFactory.CreateScanApiInstance;

这给了我关于抽象类的任何问题。

我用于SktClassFactory的SktClassFactory如下所示：

// @interface SktClassFactory : NSObject
[BaseType (typeof(NSObject))]
interface SktClassFactory
{
    // +(ISktScanObject *)createScanObject;
    [Static]
    [Export ("createScanObject")]
    ISktScanObject CreateScanObject { get; }

    // +(void)releaseScanObject:(ISktScanObject *)scanObj;
    [Static]
    [Export ("releaseScanObject:")]
    void ReleaseScanObject (ISktScanObject scanObj);

    // +(ISktScanApi *)createScanApiInstance;
    [Static]
    [Export ("createScanApiInstance")]
    ISktScanApi CreateScanApiInstance { get; }

    // +(void)releaseScanApiInstance:(ISktScanApi *)scanApi;
    [Static]
    [Export ("releaseScanApiInstance:")]
    void ReleaseScanApiInstance (ISktScanApi scanApi);

    // +(ISktScanDevice *)createDeviceInstance:(ISktScanApi *)scanApi;
    [Static]
    [Export ("createDeviceInstance:")]
    ISktScanDevice CreateDeviceInstance (ISktScanApi scanApi);

    // +(void)releaseDeviceInstance:(ISktScanDevice *)deviceInstance;
    [Static]
    [Export ("releaseDeviceInstance:")]
    void ReleaseDeviceInstance (ISktScanDevice deviceInstance);
}

编辑:我的ISktScanObject在ApiDefinition中如下所示：

// @interface ISktScanObject : NSObject
[BaseType (typeof(NSObject))]
interface ISktScanObject
{
    // -(ISktScanMsg *)Msg;
    [Export ("Msg")]
    ISktScanMsg Msg { get; }

    // -(ISktScanProperty *)Property;
    [Export ("Property")]
    ISktScanProperty Property { get; }
}

希望这有什么帮助。

Answer 2

我看到您正在绑定一个@protocol，在Philippes中，SDK更改为对这种类型使用@interface，所以他的答案并不清楚。

通过为库无法实例化的返回类型添加一个骨架接口(空接口)，并将所有返回类型和参数类型从类更改为接口名，我解决了问题(使用另一个库)。

注意添加的接口和更改的返回类型。

在此之前

// @protocol NXProximityZone <NSObject>
[Protocol, Model]
[BaseType(typeof(NSObject))]
interface NXProximityZone
{
    // Methods and properties removed for simplicity
}

// @interface NXProximityManager : NSObject
[BaseType(typeof(NSObject))]
interface NXProximityManager
{
    // +(NSObject<NXProximityZone> *)proximityZoneFromNotification:(NSNotification *)notification;
    [Static]
    [Export("proximityZoneFromNotification:")]
    NXProximityZone ProximityZoneFromNotification(NSNotification notification);

    // Methods and properties removed for simplicity
}

之后

// @protocol NXProximityZone <NSObject>
[Protocol, Model]
[BaseType(typeof(NSObject))]
interface NXProximityZone
{
    // Methods and properties removed for simplicity
}

// Skeleton interface
interface INXProximityZone { }

// @interface NXProximityManager : NSObject
[BaseType(typeof(NSObject))]
interface NXProximityManager
{
    // +(NSObject<NXProximityZone> *)proximityZoneFromNotification:(NSNotification *)notification;
    [Static]
    [Export("proximityZoneFromNotification:")]
    INXProximityZone ProximityZoneFromNotification(NSNotification notification);

    // Methods and properties removed for simplicity
}

有关框架接口的更多信息可以找到这里 (在页面中搜索骨架)