Android应用内启动相机拍照并获取照片的两种方式

首先加入需要的权限,如果是6.0系统需要加权限申请

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

方式一：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    //用于展示选择的图片
    private ImageView mImageView;

    private static final int CAMERA_CODE = 1;
    private static final int GALLERY_CODE = 2;
    private static final int CROP_CODE = 3;

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

        initView();
    }

    private void initView() {
        mImageView = (ImageView) findViewById(R.id.show_image);
        Button chooseCamera = (Button) findViewById(R.id.choose_camera);
        chooseCamera.setOnClickListener(this);
        Button chooseGallery = (Button) findViewById(R.id.choose_gallery);
        chooseGallery.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.choose_camera:
                //拍照选择
                chooseFromCamera();
                break;
            case R.id.choose_gallery:
                //从相册选取
                chooseFromGallery();
                break;
            default:
                break;
        }
    }

    /**
     * 拍照选择图片
     */
    private void chooseFromCamera() {
        //构建隐式Intent
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        //调用系统相机
        startActivityForResult(intent, CAMERA_CODE);
    }

    /**
     * 从相册选择图片
     */
    private void chooseFromGallery() {
        //构建一个内容选择的Intent
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        //设置选择类型为图片类型
        intent.setType("image/*");
        //打开图片选择
        startActivityForResult(intent, GALLERY_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode){
            case CAMERA_CODE:
                 if (resultCode == RESULT_CANCELED) {
                    Toast.makeText(this, "取消了拍照", Toast.LENGTH_LONG).show();
                    return;
                }
                if(data != null){
                      Bitmap photo = data.getParcelableExtra("data");
                        //将Bitmap转化为uri
                      Uri uri = saveBitmap(photo, "temp");
                        //启动图像裁剪
                      startImageZoom(uri);
                }
                break;
            case GALLERY_CODE:
                if (data == null){
                    return;
                }else{
                    //用户从图库选择图片后会返回所选图片的Uri
                    Uri uri;
                    //获取到用户所选图片的Uri
                    uri = data.getData();
                    //返回的Uri为content类型的Uri,不能进行复制等操作,需要转换为文件Uri
                    uri = convertUri(uri);
                    startImageZoom(uri);
                }
                break;
            case CROP_CODE:
                if (data == null){
                    return;
                }else{
                    Bundle extras = data.getExtras();
                    if (extras != null){
                        //获取到裁剪后的图像
                        Bitmap bm = extras.getParcelable("data");
                        mImageView.setImageBitmap(bm);
                    }
                }
                break;
            default:
                break;
        }
    }

    /**
     * 将content类型的Uri转化为文件类型的Uri
     * @param uri
     * @return
     */
    private Uri convertUri(Uri uri){
        InputStream is;
        try {
            //Uri ----> InputStream
            is = getContentResolver().openInputStream(uri);
            //InputStream ----> Bitmap
            Bitmap bm = BitmapFactory.decodeStream(is);
            //关闭流
            is.close();
            return saveBitmap(bm, "temp");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 将Bitmap写入SD卡中的一个文件中,并返回写入文件的Uri
     * @param bm
     * @param dirPath
     * @return
     */
    private Uri saveBitmap(Bitmap bm, String dirPath) {
        //新建文件夹用于存放裁剪后的图片
        File tmpDir = new File(Environment.getExternalStorageDirectory() + "/" + dirPath);
        if (!tmpDir.exists()){
            tmpDir.mkdir();
        }

        //新建文件存储裁剪后的图片
        File img = new File(tmpDir.getAbsolutePath() + "/avator.png");
        try {
            //打开文件输出流
            FileOutputStream fos = new FileOutputStream(img);
            //将bitmap压缩后写入输出流(参数依次为图片格式、图片质量和输出流)
            bm.compress(Bitmap.CompressFormat.PNG, 85, fos);
            //刷新输出流
            fos.flush();
            //关闭输出流
            fos.close();
            //返回File类型的Uri
            return Uri.fromFile(img);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }

    }

    /**
     * 通过Uri传递图像信息以供裁剪
     * @param uri
     */
    private void startImageZoom(Uri uri){
        //构建隐式Intent来启动裁剪程序
        Intent intent = new Intent("com.android.camera.action.CROP");
        //设置数据uri和类型为图片类型
        intent.setDataAndType(uri, "image/*");
        //显示View为可裁剪的
        intent.putExtra("crop", true);
        //裁剪的宽高的比例为1:1
        intent.putExtra("aspectX", 1);
        intent.putExtra("aspectY", 1);
        //输出图片的宽高均为150
        intent.putExtra("outputX", 150);
        intent.putExtra("outputY", 150);
        //裁剪之后的数据是通过Intent返回
        intent.putExtra("return-data", true);
        startActivityForResult(intent, CROP_CODE);
    }
}

注:第一种方式参考自冰鉴IT包括了拍照,裁剪和从相册选择图片,注释很详细.简单说明一下,通过startActivityForResult启动系统相机,然后在onActivityResult通过data.getParcelableExtra("data");方法获取到Bitmap对像,再通过IO保存到本地.

需要注意的是,这种方式获取到的图片是被系统压缩过的,优点是不容易OOM,适用于小图展示,如头像等.

下面介绍第二种,获取拍照的高清无码大图

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方式二：

先指定拍照文件的保存路径Environment.ExternalStorageDirectory/eos/time.jpg，再通过 MediaStore.ACTION_IMAGE_CAPTURE 获取系统相机，并指定 MediaStore.EXTRA_OUTPUT ，的存储位置为我们刚刚指定路径的uri，intent.putExtra(MediaStore.EXTRA_OUTPUT,currentUri); 这样，最终返回的信息会存储在我们的file中。

    private Uri currentUri;
    private final int TakePhoto = 123;

    private void openTakePhoto() {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            File appDir = new File(Environment.getExternalStorageDirectory(), "eos");
            if (!appDir.exists()) {
                appDir.mkdir();
            }
            String fileName = System.currentTimeMillis() + ".jpg";
            File file = new File(appDir, fileName);
            try {
                file.createNewFile();
                Intent intent = new Intent();
                intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
                currentUri = Uri.fromFile(file);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, currentUri);
                startActivityForResult(intent, TakePhoto);

            } catch (IOException e) {
                e.printStackTrace();
                Toast.makeText(this, "文件存储路径异常", Toast.LENGTH_SHORT).show();
            }

        } else {
            Toast.makeText(this, "请插入sd卡", Toast.LENGTH_SHORT).show();
        }
    }

在onActivityResult进行相应的处理这里使用Glide通过之前的uri显示图片，如果是需要获取图片的file或bitmap则需要进行相应的压缩，防止发生OOM

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == RESULT_CANCELED) {
//            Toast.makeText(this, "取消了拍照", Toast.LENGTH_LONG).show();
            return;
        }
        if (requestCode == TakePhoto && currentUri != null) {
            photos.add(0, new PhotoBean(currentUri, 1));
            adapter.notifyDataSetChanged();
        }

    }

dzj