在 C++ 中实现 Java 接口（通过 Delphi 桥接）

Question

我想实现一个 Java 接口（通过 Delphi 与 Java2OP 桥接）并在 C++ 中覆盖它的方法。

这之前在我的项目中使用另一个 Java SDK 成功完成，方法如下所示，我复制了（2 个持续的代码块）。

这编译正确，但我在运行时得到EJNI error："onScanComplete method not found"。

另一个问题是，如果我尝试实例化 TJBarcode2DWithSoft_ScanCallback 类并将其提供给 TJBarcode2DWithSoft->setScanCallback(_di_JBarcode2DWithSoft_ScanCallback)，我总是会收到错误消息：

ScanManager.cpp(147): no matching conversion for functional-style cast from 'Mca::Dev::Api::TJBarcode2DWithSoft_ScanCallback' to '_di_JBarcode2DWithSoft_ScanCallback' (aka 'DelphiInterface<Mca::Dev::Api::JBarcode2DWithSoft_ScanCallback>')
  systobj.h(261): candidate constructor not viable: no known conversion from 'Mca::Dev::Api::TJBarcode2DWithSoft_ScanCallback' to 'const DelphiInterface<Mca::Dev::Api::JBarcode2DWithSoft_ScanCallback>' for 1st argument
  systobj.h(268): candidate constructor not viable: no known conversion from 'Mca::Dev::Api::TJBarcode2DWithSoft_ScanCallback' to 'Mca::Dev::Api::JBarcode2DWithSoft_ScanCallback *' for 1st argument
  systobj.h(254): candidate template ignored: could not match 'DelphiInterface<type-parameter-0-0>' against 'Mca::Dev::Api::TJBarcode2DWithSoft_ScanCallback'
  systobj.h(278): candidate template ignored: disabled by 'enable_if' [with TArg = Mca::Dev::Api::TJBarcode2DWithSoft_ScanCallback &]
  systobj.h(248): candidate constructor not viable: requires 0 arguments, but 1 was provided

我想知道我是否可以像在 Java 中一样在 C++ 中使用本地类来完成所有这些操作，而无需通过 Delphi。

SDK 中的 ScanCallBack 定义：

public class Barcode2DWithSoft {
    ...
    public interface ScanCallback {
            void onScanComplete(int var1, int var2, byte[] var3);
    }
}

Java项目方式覆盖ScanCallback接口方法（无错误）：

public Barcode2DWithSoft.ScanCallback  ScanBack= new Barcode2DWithSoft.ScanCallback(){
        @Override
        public void onScanComplete(int i, int length, byte[] bytes) {
              //Code Executed on Event
        }
    };

private void ScanBarcode(){
    barcode2DWithSoft.scan();
    barcode2DWithSoft.setScanCallback(ScanBack);
}

在 Delphi 中使用的方法：ScanCallBack.pas

type
  TNotifyScanCompleteEvent = procedure(P1: Integer; P2: Integer; P3: TJavaArray<Byte>) of object;

  TAJBarcode2DWithSoft_ScanCallback = class(TJavaLocal, JBarcode2DWithSoft_ScanCallback)
   FOnScanComplet : TNotifyScanCompleteEvent;
  public
    procedure onScanComplete(P1: Integer; P2: Integer; P3: TJavaArray<Byte>); virtual; cdecl;
    property OnScanComplet: TNotifyScanCompleteEvent read FOnScanComplet write FOnScanComplet;
  end;

implementation
{ TAJBarcode2DWithSoft_ScanCallback }

procedure TAJBarcode2DWithSoft_ScanCallback.onScanComplete(P1: Integer; P2: Integer; P3: TJavaArray<Byte>);
begin
  if Assigned(FOnScanComplet) then FOnScanComplet(P1,P2,P3);
end;

在我的 C++ 项目中使用时

TAJBarcode2DWithSoft_ScanCallback * ScanListener = new TAJBarcode2DWithSoft_ScanCallback();
ScanListener->OnScanComplet = mca5OnScanCallBack;
this->ScanMCA5->setScanCallback(_di_JBarcode2DWithSoft_ScanCallback(*ScanListener));

编辑：

Java2OP 自动生成的 JBarcode2DWithSoft_ScanCallback 定义（Barcode2DWithSoft.ScanCallBack 的桥）：

  JBarcode2DWithSoft_ScanCallbackClass = interface(IJavaClass)
    ['{CC4376C0-AB56-4CE0-9612-C947DAE2160F}']
   {class} procedure onScanComplete(P1: Integer; P2: Integer; P3: TJavaArray<Byte>); cdecl;//Deprecated
  end;

  [JavaSignature('com/zebra/adc/decoder/Barcode2DWithSoft$ScanCallback')]
  JBarcode2DWithSoft_ScanCallback = interface(IJavaInstance)
    ['{202711EC-3B53-469F-B6CD-C8428226565D}']
  end;
  TJBarcode2DWithSoft_ScanCallback = class(TJavaGenericImport<JBarcode2DWithSoft_ScanCallbackClass, JBarcode2DWithSoft_ScanCallback>) end;

Answer 1

JBarcode2DWithSoft_ScanCallback 的定义自动生成不正确。它应该是这样的：

  JBarcode2DWithSoft_ScanCallbackClass = interface(IJavaClass)
    ['{CC4376C0-AB56-4CE0-9612-C947DAE2160F}']
  end;

  [JavaSignature('com/zebra/adc/decoder/Barcode2DWithSoft$ScanCallback')]
  JBarcode2DWithSoft_ScanCallback = interface(IJavaInstance)
    ['{202711EC-3B53-469F-B6CD-C8428226565D}']
    procedure onScanComplete(P1: Integer; P2: Integer; P3: TJavaArray<Byte>); cdecl;
  end;

  TJBarcode2DWithSoft_ScanCallback = class(TJavaGenericImport<JBarcode2DWithSoft_ScanCallbackClass, JBarcode2DWithSoft_ScanCallback>) end;