public class RMainActivity extends AppCompatActivity {
    private TextView mTvResult;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ractivity_main);
        mTvResult= (TextView) findViewById(R.id.tv_result);
    }
    public void readQR(View view){
        startActivityForResult(new Intent(RMainActivity.this,CaptureActivity.class),0 );
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(resultCode==RESULT_OK){
            Bundle bundle=data.getExtras();
            String result=bundle.getString("result");
            mTvResult.setText(result);
        }
    }
}