获取用户的Facebook权限

Question

我想为我的用户添加facebook权限。 我就是这样做的：

Session.openActiveSession(this, true, new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state, Exception exception) {
            if (session.isOpened()) {
                List<String> PERMISSIONS = Arrays.asList("email");

                if (!session.getPermissions().containsAll(PERMISSIONS)) {
                    Session.NewPermissionsRequest newPermissionsRequest = new Session.NewPermissionsRequest(MainActivity.this,
                            PERMISSIONS);
                    session.requestNewReadPermissions(newPermissionsRequest);
                }

                Request.newMeRequest(session, new Request.GraphUserCallback() {
                    @Override
                    public void onCompleted(GraphUser user, Response response) {
                        if (user != null) {
                            Toast.makeText(MainActivity.this, user.asMap().get("email").toString(), Toast.LENGTH_LONG).show();
                        }
                    }
                }).executeAsync();
            }
        }
    });

问题是我不想每次都打开一个会话，只要用户没有这个权限。 有没有办法在本地知道用户是否已经在我的应用程序中批准了此权限？

Answer 1

使用下面的代码

Session session = getActiveSession();
if(session.isOpened)
{
  List<String> permissions = session.getPermissions();
    if(!permissions.contain("email"))
    {
 Session.NewPermissionsRequest newPermissionsRequest = new Session.NewPermissionsRequest(MainActivity.this,
                            PERMISSIONS);
                    session.requestNewReadPermissions(newPermissionsRequest);

}
}else
{
Session.openActiveSession(this, true,callback);
}