1、需要设置访问权限：

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

2、点击拍照时判断是否获取手机拍照权限

 public void takePhone(View view){
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
            != PackageManager.PERMISSION_GRANTED){
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.CAMERA},
                MY_PERMISSIONS_REQUEST_CALL_PHONE2);
    }else{
        takePhoto();
    }
}

3、开始拍照

public void takePhoto(){
   // 创建文件夹
   File file = new File(Environment.getExternalStorageDirectory(),"my_photo") ;
   if (!file.exists()){
       file.mkdir();
   }

   // 将时间作为不同照片的名称
    output = new File(file,System.currentTimeMillis()+".jpg");

   // 如果该文件夹已经存在，则删除，重建一个
    try {
        if (output.exists()){
            output.delete();
        }
        output.createNewFile();
    }catch (Exception e){
        e.printStackTrace();
    }

    // 隐式打开拍照的activity，并传入CROP_PHOTO常量作为拍照结束后回调的标志
    imageUri = Uri.fromFile(output);
    Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
    intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);
    startActivityForResult(intent,CROP_PHOT);
}

4、判断是否有访问相册权限

  public void choosePhone(View view){
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED)
    {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                MY_PERMISSIONS_REQUEST_CALL_PHONE2);

    }else {
        choosePhoto();
    }
}

5、选择相册中的照片

public void choosePhoto(){
    // 打开选择相册的界面
    Intent intent = new Intent(Intent.ACTION_PICK);
    intent.setType("image/*");//相片类型
    startActivityForResult(intent, REQUEST_CODE_PICK_IMAGE);
}

6、获取照片后处理

   public void onActivityResult(int req, int res, Intent data) {
    switch (req) {
        /**
         * 拍照的请求标志
         */
        case CROP_PHOT:
            if (res==RESULT_OK) {
                try {
                    /**
                     * 该uri就是照片文件夹对应的uri
                     */
                    Bitmap bit = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                    imageView.setImageBitmap(bit);
                } catch (Exception e) {
                    Toast.makeText(this,"程序崩溃",Toast.LENGTH_SHORT).show();
                }
            }
            else{
                Log.i("tag", "失败");
            }

            break;
        /**
         * 从相册中选取图片的请求标志
         */

        case REQUEST_CODE_PICK_IMAGE:
            if (res == RESULT_OK) {
                try {
                    /**
                     * 该uri是上一个Activity返回的
                     */
                    Uri uri = data.getData();
                    Bitmap bit = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri));
                    imageView.setImageBitmap(bit);
                } catch (Exception e) {
                    e.printStackTrace();
                    Log.d("tag",e.getMessage());
                    Toast.makeText(this,"程序崩溃",Toast.LENGTH_SHORT).show();
                }
            }
            else{
                Log.i("liang", "失败");
            }

            break;

        default:
            break;
    }
}

7、获取权限result

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults)
{

    if (requestCode == MY_PERMISSIONS_REQUEST_CALL_PHONE)
    {
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
        {
            takePhoto();
        } else
        {
            // Permission Denied
            Toast.makeText(MainActivity.this, "Permission Denied", Toast.LENGTH_SHORT).show();
        }
    }


    if (requestCode == MY_PERMISSIONS_REQUEST_CALL_PHONE2)
    {
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
        {
            choosePhoto();
        } else
        {
            // Permission Denied
            Toast.makeText(MainActivity.this, "Permission Denied", Toast.LENGTH_SHORT).show();
        }
    }
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}

注：以上用的的变量

private ImageView imageView;
private static final int CROP_PHOT = 2;
private static final int REQUEST_CODE_PICK_IMAGE=3;
private static final int MY_PERMISSIONS_REQUEST_CALL_PHONE = 6;
private static final int MY_PERMISSIONS_REQUEST_CALL_PHONE2 = 7;
private File output;
private Uri imageUri;