[Android] Android 连接蓝牙扫码器 无输入框

@Override
  public boolean dispatchKeyEvent(KeyEvent event) {
    InputDevice inputDevice = event.getDevice();
    if (inputDevice != null) {
      int keyboardType = event.getDevice().getKeyboardType();
      String deviceName = event.getDevice().getName();
      boolean isVirtual = event.getDevice().isVirtual();
      //可以根据输入设备信息判断是否为特定扫码器输入
      if (!isVirtual) {
        scannerHelper.onScanerInput(event);
      }
    }
  }

public class ScannerHelper {
  private String buffer ="";
  private MainOneActivity mainOneActivity;
  public ScannerHelper(MainOneActivity mainOneActivity){
    this.mainOneActivity = mainOneActivity;
  }
  public void onScanerInput(KeyEvent event){
    if(event.getKeyCode() == KeyEvent.KEYCODE_ENTER){
      mainOneActivity.onScannerResult(buffer);//回调扫码结果
      buffer="";
    }else{
      if (event.getAction() == KeyEvent.ACTION_UP && event.isPrintingKey()){
        buffer +=  (char)event.getUnicodeChar();
      }
    }
  }
}