android模仿微信相册多选。预览，删除

1.打开相机以及查看相册都需要对应的权限

android6.0以上需要动态申请权限：

 if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            //申请WRITE_EXTERNAL_STORAGE权限
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, 1);
        } else {
            
        }

申请成功的回调：

  @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == 1) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            //申请成功，可以拍照
                camera();
        }
        return;
    }
    }

打开相机的方法：

 public void camera(){
        Intent getImageByCamera = new Intent("android.media.action.IMAGE_CAPTURE");
        File file = new File(Environment.getExternalStorageDirectory() + "/DCIM/Camera/IMG_" + System.currentTimeMillis() + ".jpg");
        if (file.exists()) {
            file.delete();
        }
        //指定uri存储相片
        getImageByCamera.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
        uri = Uri.fromFile(file);
        startActivityForResult(getImageByCamera, RESULT_CAMERA);
    }

拍照成功的回调：

 	if (requestCode == RESULT_CAMERA) {
//           //拍照成功的回调
            Intent intent = new Intent(MainActivity.this,WritingActivity.class);
            intent.putExtra("data2", uri.toString());
            startActivity(intent);
        }

2.android自带的相册是不能多选的，想要多选就必须自定义相册，创造自定义相册有比较重要的几个方法：

 /*
    获取相册列表
     */
    public List getAlbums() {
        List albums = new ArrayList();
        Cursor cursor = resolver.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[]{MediaStore.Images.ImageColumns.DATA,
                MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME, MediaStore.Images.ImageColumns.SIZE}, null, null, null);
        if (cursor == null || !cursor.moveToNext())
            return new ArrayList();
        cursor.moveToLast();
        PhotoDerictoryBean photoDerictoryBean = null;
        boolean falg = true;
        do {
            falg = true;
            if (cursor.getInt(cursor.getColumnIndex(MediaStore.Images.ImageColumns.SIZE)) < 1024 * 10)
                continue;
            String name = cursor.getString(cursor.getColumnIndex(MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME));
            photoDerictoryBean = new PhotoDerictoryBean(name);
            photoDerictoryBean.setImg(cursor.getString(cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA)));
            photoDerictoryBean.setNum(1);
            for (PhotoDerictoryBean p : albums) {
                if (p.getName().equals(photoDerictoryBean.getName())) {
                    p.setNum(p.getNum() + 1);
                    falg = false;
                }
            }
            if (falg) {
                albums.add(photoDerictoryBean);
            }

        } while (cursor.moveToPrevious());
        if (cursor != null) {
            cursor.close();
        }
        return albums;
    }

    /*
    根据名字获取对应相册下的图片
     */
    public List getAlbum(String name) {
        Cursor cursor = resolver.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[]{MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME,
                        MediaStore.Images.ImageColumns.DATA, MediaStore.Images.ImageColumns.DATE_ADDED, MediaStore.Images.ImageColumns.SIZE}, "bucket_display_name = ?",
                new String[]{name}, MediaStore.Images.ImageColumns.DATE_ADDED);
        if (cursor == null || !cursor.moveToNext())
            return new ArrayList();
        List photos = new ArrayList();
        cursor.moveToLast();
        do {
            if (cursor.getLong(cursor.getColumnIndex(MediaStore.Images.ImageColumns.SIZE)) > 1024 * 10) {
                photos.add(new PhotoBean(cursor.getString(cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA)), true, false));
            }
        } while (cursor.moveToPrevious());
        if (cursor != null) {
            cursor.close();
        }
        return photos;
    }

 //获取最近照片
    public List getCurrent() {
        Cursor cursor = resolver.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[]{MediaStore.Images.ImageColumns.DATA,
                MediaStore.Images.ImageColumns.DATE_ADDED, MediaStore.Images.ImageColumns.SIZE}, null, null, MediaStore.Images.ImageColumns.DATE_ADDED);
        if (cursor == null || !cursor.moveToNext())
            return new ArrayList();
        List photos = new ArrayList();
        cursor.moveToLast();
        PhotoBean bean = null;
        do {
            if (cursor.getLong(cursor.getColumnIndex(MediaStore.Images.ImageColumns.SIZE)) > 1024 * 10) {
                String path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA));
                bean = new PhotoBean(path, true, false);
                photos.add(bean);
            }
        } while (cursor.moveToPrevious());
        if (cursor != null) {
            cursor.close();
        }
        return photos;
    }

3.拿到图片资源了，剩下的页面逻辑自己处理好就没问题了，不会处理?来来来，靠近点，我慢慢给你说...

Demo地址：http://download.csdn.net/download/qq_34963282/9957511