Question

我有一个带有内置条形码扫描仪的android设备CipherLab RS31。我正在尝试以编程方式设置一些阅读器参数（支持的条形码，用户首选项等）。但是我总是得到一个例外

Attempt to invoke interface method 'int com.cipherlab.barcodebase.IBarcodeReaderServiceInterface.WriteOutputSettings(com.cipherlab.barcode.decoderparams.ReaderOutputConfiguration)' on a null object reference

这是我的代码：

public class BarCodeActivity extends Activity {
    private ReaderManager readerManager;
    private IntentFilter filter;

    protected void onCreate(@Nullable Bundle savedInstanceState) {
        readerManager = ReaderManager.InitInstance(this);
        filter = new IntentFilter();
        filter.addAction(GeneralString.Intent_PASS_TO_APP);
        registerReceiver(broadcastReceiver, filter);

        configureReader();
    }

    private void configureReader() {
        Decoders decoders = new Decoders();
        decoders.enableQRcode = Enable_State.TRUE;

        //this is the line where the exception occurs
        readerManager.Set_Decoders_Status(decoders);
    }
}

调用Set_ReaderOutputConfiguration类的以下方法Set_Symbology，Set_UserPreferences，ReaderManager时，会发生相同的异常。

Answer 1

在阅读器管理器上执行任何工作之前，您需要等待GeneralString.Intent_READERSERVICE_CONNECTED意图触发：

filter = new IntentFilter();
filter.addAction(GeneralString.Intent_PASS_TO_APP);
registerReceiver(broadcastReceiver, filter);

然后在您的BroadcastReceiver实现中：

@Override
public void onReceive(Context context, Intent intent) {
     if(intent.getAction().equals(GeneralString.Intent_READERSERVICE_CONNECTED)){
         // do configuration here
     }
}

CipherLab无法设置阅读器配置

1 个答案: