接口实现C#与Java的差异

Question

我已经为一个java库创建了一个绑定,它作为扫描仪SDK的一部分提供,模型是Honeywell Dolphin CT50.但是,在我的理解中,我遇到了一些问题.

以下示例在Java中给出.Create方法需要一个接口实现.但是,我还没有意识到在仍然访问类范围变量时覆盖接口的'onCreated'方法的类似方法.这是我遇到麻烦,我怎么能在C#中做到以下几点.

Java的:

private static BarcodeReader barcodeReader;
private AidcManager manager;

public void onCreate(Bundle savedInstanceState) {
    // create the AidcManager providing a Context and a
    // CreatedCallback implementation.
    AidcManager.create(this, new CreatedCallback() {
        @Override
        public void onCreated(AidcManager aidcManager) {
            manager = aidcManager;
            barcodeReader = manager.createBarcodeReader();
        }
    });

}

在.NET中,编译器不会像上面那样执行并将接口实现为匿名类型,因此我必须实现接口.但是,我怎么能分配类宽变量？

我的C#:

NameSpace Scanner {
    private static BarcodeReader barcodeReader;
    private AidcManager manager;
    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);

       CreateCallback callback = new CreateCallback() {  };
       AidcManager.Create(this, callback.OnCreated(AidcManager aidcManager));
    }

public class CreateCallback : AidcManager.ICreatedCallback
{
    public IntPtr Handle
    {
        get
        {
            throw new NotImplementedException();
        }
    }
    public void Dispose()
    {
        throw new NotImplementedException();
    }
    public void OnCreated(AidcManager p0)
    {
        // How can I initialize the manager and barcode reader variables in the class above from here?
    }
  }
}

Answer 1

您可以创建一个CreateCallback具有其他回调作为构造函数参数的回调实现successAction.这通过回调OnManagerCreated将在被调用OnCreated的CreateCallback.

重要说明:如果实现Java接口,则必须继承Java.Lang.Object.不要不落实Handle和Dispose()你自己的.

活动

public class MyActivity : Activity 
{
    private static BarcodeReader _barcodeReader;
    private AidcManager _manager;
    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);

        CreateCallback callback = new CreateCallback(OnManagerCreated) {  };
        AidcManager.Create(this, callback);
    }

    private void OnManagerCreated(AidcManager manager)
    {
        _manager = manager;
        _barcodeReader = manager.CreateBarcodeReader();
    }
}

回调实现

public class CreateCallback : Java.Lang.Object, AidcManager.ICreatedCallback
{
    private Action<AidcManager> _successAction;
    public CreateCallback(Action<AidcManager> successAction)
    {
        _successAction = successAction;
    }

    public void OnCreated(AidcManager p0)
    {
        _successAction(p0);
    }
}

其他可能性

您也可以直接在您的活动类中实现界面

public class MyActivity : Activity, AidcManager.ICreatedCallback 
{
    // ...
}