如何将QR码扫描成字符串得到的值？

Question

如何通过扫描qr代码然后将其放入字符串中来获取值？

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_qrscanner);
    fragment = (BarcodeFragment)getSupportFragmentManager().findFragmentById(R.id.sample);
    fragment.setScanResultHandler(this);
    btn = ((Button)findViewById(R.id.scan));
    btn.setEnabled(false);

}