Android调用系统摄像头拍照并显示在ImageView上

<?xml version="1.0" encoding="utf-8"? 
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 tools:context="com.cc.csdndemo1.MainActivity" 

 <Button
 android:id="@+id/takephotoTV"
 android:text="开启相机"
 android:gravity="center"
 android:layout_width="match_parent"
 android:layout_height="wrap_content" / 

 <ImageView
 android:layout_gravity="center"
 android:id="@+id/imageIV"
 android:layout_width="300dp"
 android:layout_height="300dp"/ 

</LinearLayout 

package com.cc.csdndemo1;

import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Button;
import android.widget.ImageView;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {


 @BindView(R.id.takephotoTV)
 Button takephotoTV;
 @BindView(R.id.imageIV)
 ImageView imageIV;

 private final int CAMERA_REQUEST = 8888;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 ButterKnife.bind(this);
 }


 @OnClick(R.id.takephotoTV)
 public void onClick() {
 Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
 startActivityForResult(cameraIntent, CAMERA_REQUEST);
 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {
 Bitmap photo = (Bitmap) data.getExtras().get("data");
 imageIV.setImageBitmap(photo);
 }
 }
}