我不知道我的代码中是否遗漏了某些内容，但我有一个viewpager有4个标签。其中一个是寻找FaceBook的朋友。您可以使用FaceBook登录应用程序，但是当您在此选项卡中时，如果您没有使用FaceBook登录，它将显示一个登录按钮以获取正在玩游戏的任何朋友。在用户点击按钮并登录成功后，一切看起来都很好，这个人可以看到他们所有的朋友。但是，如果此人杀死应用程序然后重新打开应用程序，它将再次显示该按钮而不是已登录的人。如果currentaccesstoken为空，则显示该按钮，并且由于此人已登录，因此不应为null。请帮忙。
这是我的代码：
public class FacebookFriends extends ListFragment
implements ListAdapterAddFriends.customButtonListener {
//variable declaration/initialization
public static final String TAG = FacebookFriends.class.getSimpleName(); //tag with class name
protected ParseObject mFriendsRelation; //parse object for friend relation table
protected List<ParseUser> mUsers; //list of ParseUsers
protected ParseUser mCurrentUser; //ParseUser to get the current user
private ListView listView; //Listview for facebook friends
private TextView empty;
ListAdapterAddFriends adapter; //adapter from the listAdapterAddFriends Class
Toolbar mToolbar; //Custom Toolbar
ProgressBar progressBar; //Progress bar to indicate when loading
String[] friendId; //getting friendID from Facebook
String[] friendName; //getting friendName from Facebook
// Creating Facebook CallbackManager Value
public static CallbackManager callbackmanager;
View mRootView;
Button facebookLoginButton;
/**
* Method that start this class
*
* @param savedInstanceState this will save an instance of the class when resume
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mRootView = inflater.inflate(R.layout.tab_facebook_friends, container, false);
setHasOptionsMenu(true);
//initializing facebook button
facebookLoginButton = (Button) mRootView.findViewById(R.id.facebook_login);
facebookLoginButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
facebookLogin();
}
});
//initializing empty text
empty = (TextView) mRootView.findViewById(android.R.id.empty);
//initializing listview
listView = (ListView) mRootView.findViewById(android.R.id.list);
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
return mRootView;
}
/**
* this method is call when the app in resume
*/
@Override
public void onResume() {
super.onResume();
mCurrentUser = ParseUser.getCurrentUser(); //getting current user
if (AccessToken.getCurrentAccessToken() == null) {
facebookLoginButton.setVisibility(View.VISIBLE);
empty.setVisibility(View.INVISIBLE);
} else {
getFacebookFriends(); //calling method to look for facebook friends
}
}
/**
* method that look for facebook friends with facebook api
*/
private void getFacebookFriends() {
mCurrentUser = ParseUser.getCurrentUser();
/* make the API call */
new GraphRequest(
AccessToken.getCurrentAccessToken(),
"/me/friends",
null,
HttpMethod.GET,
new GraphRequest.Callback() {
public void onCompleted(GraphResponse response) {
/* handle the result */
JSONObject jsonObject = response.getJSONObject();
try {
JSONArray data = jsonObject.getJSONArray("data");
friendId = new String[data.length()];
friendName = new String[data.length()];
for (int i = 0; i < data.length(); i++) {
JSONObject jsonFriends = data.getJSONObject(i);
friendId[i] = jsonFriends.getString("id");
friendName[i] = jsonFriends.getString("name");
}
} catch (JSONException e) {
e.printStackTrace();
}
ParseQuery<ParseUser> query = ParseUser.getQuery();
if (friendId.length > 1) {
query.whereContainedIn("facebookID", Arrays.asList(friendId));
} else {
query.whereEqualTo("facebookID", friendId[0]);
}
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> usr, ParseException e) {
//getActivity().setProgressBarIndeterminateVisibility(false);
if (e == null) {
// The query was successful.
mUsers = usr;
addFriendCheckMarks(mUsers);
adapter = new ListAdapterAddFriends(getListView().getContext(),
mUsers);
adapter.setCustomButtonListener(FacebookFriends.this);
listView.setAdapter(adapter);
} else {
// Something went wrong.
Log.e("ERROR", e.getMessage());
AlertDialog.Builder builder =
new AlertDialog.Builder(getActivity());
builder.setMessage(e.getMessage())
.setTitle("Oops we are sorry")
.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}
}
});
}
}
).executeAsync();
}
private void facebookLogin() {
callbackmanager = CallbackManager.Factory.create();
// Set permissions
LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile", "user_friends"));
LoginManager.getInstance().registerCallback(callbackmanager,
new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
GraphRequest.newMeRequest(
loginResult.getAccessToken(), new GraphRequest.GraphJSONObjectCallback() {
@Override
public void onCompleted(JSONObject json, GraphResponse response) {
if (response.getError() != null) {
// handle error
System.out.println("ERROR");
} else {
System.out.println("Success");
try {
ParseUser parseUser = ParseUser.getCurrentUser();
if (json != null && parseUser != null
&& json.optString("name").length() > 0) {
parseUser.put("facebookID", json.getString("id"));
parseUser.saveInBackground(new SaveCallback() {
@Override
public void done(ParseException e) {
if (e == null) {
}
}
});
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}).executeAsync();
}
@Override
public void onCancel() {
Log.d("CANCEL", "On cancel");
}
@Override
public void onError(FacebookException error) {
Log.d("ERROR", error.toString());
}
});
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackmanager.onActivityResult(requestCode, resultCode, data);
}
}
我错过了什么吗？我正在应用程序类中初始化我的sdk，如此//initializing parsefacebookutil to signup/signin with facebook
ParseFacebookUtils.initialize(this);