用sdk 3.5在android上显示facebook好友列表

Question

我只是在列表视图中只显示个人资料列表和名称时遇到问题。

我认为我很接近，这是我的代码和我到目前为止遇到的麻烦：

public class TestActivity extends SherlockActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);
        ListView lv = (ListView) findViewById(R.id.listView);

        ...

    // Check for an open session
    Session session = Session.getActiveSession();
    if (session != null && session.isOpened()) {
        // Get the friendlist data;
        requestFacebookFriends(session);
    }
        /*ListView lv = (ListView) findViewById(R.id.listView);  
        aAdpt = new FriendListAdapter(friendlist,this);
        lv.setAdapter(aAdpt);*/
        // If I do that I get an Nullpointer from the adapter because at this point the friendlist is null
}

private void requestFacebookFriends(final Session session) {
    Request friendrequest = Request.newMyFriendsRequest(session,
            new Request.GraphUserListCallback() {

        @Override
        public void onCompleted(List<GraphUser> users,
                Response response) {
            if(users != null){
                for(int i=0; i < users.size();i++){
                GraphUser user = users.get(i);
                Friends friend = new Friends();
                friend.setFriendsID(user.getId());
                friend.setFriendsUserNameView(user.getName());
                //friend.setFriendsProfilePictureView(user.getId());


                friendlist.add(friend);

                Log.d(TAG,"User ID "+ user.getName());
                }
            }
        }
    });
    friendrequest.executeAsync();
}

所以我想我在这里做错了，我也尝试在循环后从onCompleted方法启动适配器，但是我无法使它工作。

有任何线索吗？ 如果需要，我会用我的适配器更新我的诗句，但我不认为问题来自那里。

编辑： logcat的：

01-11 04:03:19.848: E/AndroidRuntime(6653): FATAL EXCEPTION: main
01-11 04:03:19.848: E/AndroidRuntime(6653): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myfirstapp/com.example.myfirstapp.TestActivity}: java.lang.NullPointerException
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.os.Looper.loop(Looper.java:137)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.ActivityThread.main(ActivityThread.java:4424)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at java.lang.reflect.Method.invokeNative(Native Method)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at java.lang.reflect.Method.invoke(Method.java:511)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at dalvik.system.NativeStart.main(Native Method)
01-11 04:03:19.848: E/AndroidRuntime(6653): Caused by: java.lang.NullPointerException
01-11 04:03:19.848: E/AndroidRuntime(6653):     at com.example.myfirstapp.FriendListAdapter.getCount(FriendListAdapter.java:26)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.widget.ListView.setAdapter(ListView.java:460)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at com.example.myfirstapp.TestActivity.onCreate(TestActivity.java:69)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.Activity.performCreate(Activity.java:4465)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
01-11 04:03:19.848: E/AndroidRuntime(6653):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
01-11 04:03:19.848: E/AndroidRuntime(6653):     ... 11 more

但正如我之前所说，我知道错误是由于我的朋友列表在我调用适配器时为空。