我有一个片段，我在MainActivity OnCreate方法中调用它。在这个片段中，我要求用户登录脸书。我的代码是这样的：
public class FbLogin extends Fragment {
private AccessToken accessToken;
private Profile profile;
private ProfileTracker profileTracker;
static AccessTokenTracker tracker;
private ProfilePictureView profilepic;
LoginButton loginButton;
LoginPrefrence loginPrefrence ;
private CallbackManager mcallbackManager;
private FacebookCallback<LoginResult> mcallback = new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
accessToken = loginResult.getAccessToken();
profile = Profile.getCurrentProfile();
getFbData(profile);
GraphRequest request = GraphRequest.newMeRequest(
loginResult.getAccessToken(),
new GraphRequest.GraphJSONObjectCallback() {
@Override
public void onCompleted(JSONObject object, GraphResponse graphResponse) {
Log.d("Amc", graphResponse.toString());
try {
String id = object.getString("id");
String name = object.getString("name");
// String email = object.getString("email");
String gender = object.getString("gender");
profilepic.setProfileId(object.getString("id"));
//if want to make it round
/*
profileImageView = ((ImageView)faceBookProfilePictureView.getChildAt(0));
bitmap = ((BitmapDrawable)profileImageView.getDrawable()).getBitmap();
circular.setImageBitmap(bitmap);
profilepic.getChildAt(0);
*/
// String birthday = object.getString("birthday");
// String Uri1 =(object.getJSONObject("picture").getJSONObject("data").getString("url"));
Log.d("Amc2",""+id + ", " + name + ", " +""+ ""+ ", " + gender + ", " );
} catch (JSONException e) {
e.printStackTrace();
Log.d("Amc2",""+e.toString());
}
}
});
Bundle parameters = new Bundle();
parameters.putString("fields", "id,name,email,gender, birthday");
request.setParameters(parameters);
request.executeAsync();
}
@Override
public void onCancel() {
}
@Override
public void onError(FacebookException e) {
}
};
public FbLogin() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getActivity().getApplicationContext());
mcallbackManager = CallbackManager.Factory.create();
tracker = new AccessTokenTracker() {
@Override
protected void onCurrentAccessTokenChanged(AccessToken oldToken, AccessToken newToken) {
}
};
profileTracker = new ProfileTracker() {
@Override
protected void onCurrentProfileChanged(Profile oldProfile, Profile newProfile) {
getFbData(newProfile);
}
};
tracker.startTracking();
profileTracker.startTracking();
}
@Override
public void onStop() {
super.onStop();
tracker.stopTracking();
profileTracker.stopTracking();
}
@Override
public void onPause() {
super.onPause();
profileTracker.stopTracking();
tracker.stopTracking();
}
@Override
public void onDestroy() {
super.onDestroy();
tracker.stopTracking();
profileTracker.stopTracking();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_fb_login, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
profilepic = (ProfilePictureView)view.findViewById(R.id.pf_view);
loginPrefrence = new LoginPrefrence(getActivity());
loginButton = (LoginButton) view.findViewById(R.id.login_button);
loginButton.setReadPermissions(Arrays.asList("public_profile","email","user_birthday"));
loginButton.setFragment(this);
loginButton.registerCallback(mcallbackManager, mcallback);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
mcallbackManager.onActivityResult(requestCode, resultCode, data);
}
public void getFbData(Profile prof) {
if (prof != null) {
Log.d("Facebook", prof.getFirstName());
Log.d("Facebook", prof.getName());
Log.d("Facebook", prof.getId().toString());
}
}
}
这是一个简单的Facebook登录代码。但我想做以下
请帮助我，我已经尝试过所有的事情，但没有什么能真正帮助我。
答案 0 :(得分：0)
使用以下代码行检查当前访问令牌
private Boolean isUserLoggedIn(){
if (AccessToken.getCurrentAccessToken() != null) {
//user is logged in already
return true;
}else{
return false;
}
}