Android - Fotos e imageView

package com.example.escanerbarra;

import android.content.Intent;

import android.graphics.Bitmap;

import android.provider.MediaStore;

import android.support.annotation.Nullable;

import android.support.v7.app.AlertDialog;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ImageView;

import com.google.zxing.Result;

import me.dm7.barcodescanner.zxing.ZXingScannerView;

public class MainActivity extends AppCompatActivity {

    private ZXingScannerView escanerView;

    public ImageView imageView;

    Button button,escaner;

    EditText codigo;

    Bitmap bitmap;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        button = (Button) findViewById(R.id.tomarfoto);

        escaner=(Button)  findViewById(R.id.escaner);

        imageView = (ImageView) findViewById(R.id.imageViewId);

    }

    public void HacerFoto(View view) {

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        startActivityForResult(intent, 0);

    }

    @Override

    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {

        super.onActivityResult(requestCode, resultCode, data);

        bitmap = (Bitmap) data.getExtras().get("data");

        imageView.setImageBitmap(bitmap);

    }

    /**

     * @param view

     */

    public void EscanerQR(View view) {

        escanerView = new ZXingScannerView(this);

        escanerView.setResultHandler(new zxingscanner());

        setContentView(escanerView);

        escanerView.startCamera();

    }

    class zxingscanner implements ZXingScannerView.ResultHandler {

        @Override

        public void handleResult(Result resul) {

            String dato = resul.getText();

            setContentView(R.layout.activity_main);

            escanerView.stopCamera();

            codigo = (EditText) findViewById(R.id.edtCodigo);

            codigo.setText(dato);

            imageView.setImageBitmap(bitmap);

        }

    }

}