Facebook Share在android中无效

Question

FacebookCallback<Sharer.Result> shareCallback = new FacebookCallback<Sharer.Result>() {
                @Override
                public void onCancel() {
                    Log.d("cancled", "fb SHARE canceled");
                }

                @Override
                public void onError(FacebookException error) {
                    Log.d("Error", "fb SHARE error");
                }

                @Override
                public void onSuccess(Sharer.Result result) {

                    String postId = result.getPostId();
                    if (postId != null)
                    {
                        // record successful FB share
                        Log.d("Success", "fb SHARE success");
                    }
                }
            };
            Log.d("facebook", "inside");
            shareDialog = new ShareDialog(getActivity());
            CallbackManager callbackManager = CallbackManager.Factory.create();
            ShareLinkContent content = new ShareLinkContent.Builder()
                    .setContentUrl(Uri.parse(sharefburl))
                    .build();
            shareDialog.show(content,ShareDialog.Mode.FEED);
            shareDialog.registerCallback(callbackManager, shareCallback);

以上是从我的Android应用程序在Facebook上共享URL的代码。我可以在Facebook上分享它，但是当共享成功时，我想在我的应用程序中显示Toast消息，无论共享是否成功。如何工作我无法得到这段代码的问题。我是应用程序开发的新手。