Java 设置facebook登录回调无法解析为变量

我遵循本教程：

以下是我的欢迎活动（主要活动）的代码：

这是我的MainFragment.java类的代码：

package de.test.test;

import java.util.Arrays;

import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.widget.LoginButton;

import android.app.Activity;
import android.content.Intent;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MainFragment extends Fragment {
    private static final String TAG = "MainFragment";
    private UiLifecycleHelper uiHelper;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    uiHelper = new UiLifecycleHelper(getActivity(), callback);
    uiHelper.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    View view = inflater.inflate(R.layout.welcome, container, false);
    LoginButton authButton = (LoginButton) view.findViewById(R.id.like_fb);
    authButton.setFragment(this);
    authButton.setReadPermissions(Arrays.asList("user_likes"));
    return view;
}

private void onSessionStateChange(Session session, SessionState state,
        Exception exception) {
    if (state.isOpened()) {
        Log.i(TAG, "Logged in...");
    } else if (state.isClosed()) {
        Log.i(TAG, "Logged out...");
    }
}

private Session.StatusCallback callback = new Session.StatusCallback() {
    @Override
    public void call(Session session, SessionState state,
            Exception exception) {
        onSessionStateChange(session, state, exception);
    }
};

@Override
public void onResume() {
    super.onResume();
    // For scenarios where the main activity is launched and user
    // session is not null, the session state change notification
    // may not be triggered. Trigger it if it's open/closed.
    Session session = Session.getActiveSession();
    if (session != null &&
           (session.isOpened() || session.isClosed()) ) {
        onSessionStateChange(session, session.getState(), null);
    }

    uiHelper.onResume();
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    uiHelper.onActivityResult(requestCode, resultCode, data);
}

@Override
public void onPause() {
    super.onPause();
    uiHelper.onPause();
}

@Override
public void onDestroy() {
    super.onDestroy();
    uiHelper.onDestroy();
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    uiHelper.onSaveInstanceState(outState);
}

我不确定这是否正确。在这两个类中，我都有这个“uiHelper”。此外，我的欢迎活动中出现以下错误：

uiHelper = new UiLifecycleHelper(this, callback);

表示“回调无法解析为变量”

---

谢谢

你是否错过了这两个类的右大括号，或者你就是这样发布的？这可能会引起一些问题。这就是我发布它的方式。它们在日食中，好的。嗯，我没有看到任何明显的错误。我现在没有时间设置Android SDK，所以希望已经拥有它的人能过来帮忙。

uiHelper = new UiLifecycleHelper(this, callback);