private void updateApp(File body) {

        Intent intent = new Intent(Intent.ACTION_VIEW);

        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        //判断是否是AndroidN以及更高的版本

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {

            Uri contentUri = FileProvider.getUriForFile(AboutAppActivity.this, BuildConfig.APPLICATION_ID + ".fileProvider", body);

            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

            intent.setDataAndType(contentUri, "application/vnd.android.package-archive");

        } else {

            intent.setDataAndType(Uri.fromFile(body), "application/vnd.android.package-archive");

        }

        AboutAppActivity.this.startActivity(intent);

    }