Android6.0以后动态增加权限

  private void test() throws IOException {

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            int hasWritePermission = checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE);
            if (hasWritePermission != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 101);
                return;
            }
        }
　　　　//操作
}

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

        if (requestCode == 101) {

            if (permissions[0].equals(Manifest.permission.WRITE_EXTERNAL_STORAGE)//
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                try {
                    test();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                Toast.makeText(this, "拒绝了权限", Toast.LENGTH_SHORT).show();
            }

        }
    }