圖形API在android

Question

中無法正常工作我正在集成Facebook登錄我的android應用程序並使用Graph API訪問用戶信息。

我收到一個不尋常的行爲，當我啓動的應用程序中，我沒有登錄Facebook，然後嘗試登錄Facebook，然後它允許我成功登錄，但不允許獲取用戶信息（即JSON對象上的NullPointerException），並崩潰。

另一方面，如果我再次重新啓動已登錄的應用程序（在應用程序崩潰之前成功登錄），然後按下注銷按鈕，然後再次登錄按鈕。現在奇怪的事情發生了，我可以在成功登錄後訪問用戶信息。請幫助我在第一種情況下訪問用戶信息。

這裏是我的代碼：

public class Login extends Activity implements View.OnClickListener{ 

private LoginButton facebookLogin; 
private CallbackManager callbackManager; 
private AccessTokenTracker accessTokenTracker; 
private AccessToken accessToken; 
private Profile facebookProfile; 
private ProfileTracker profileTracker; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    FacebookSdk.sdkInitialize(this.getApplicationContext()); 
    setContentView(R.layout.activity_login); 
    callbackManager = CallbackManager.Factory.create(); 

    accessTokenTracker = new AccessTokenTracker() { 
     @Override 
     protected void onCurrentAccessTokenChanged(
       AccessToken oldAccessToken, 
       AccessToken currentAccessToken) { 
      // Set the access token using 
      // currentAccessToken when it's loaded or set. 
     } 
    }; 

    // If the access token is available already assign it. 
    accessToken = AccessToken.getCurrentAccessToken(); 

    facebookProfile = Profile.getCurrentProfile(); 

    /*profileTracker = new ProfileTracker() { 
     @Override 
     protected void onCurrentProfileChanged(
       Profile oldProfile, 
       Profile currentProfile) { 
      // App code 
     } 
    };*/ 

    facebookLogin = (LoginButton)findViewById(R.id.button_facebookLogin_Login); 
    facebookLogin.setReadPermissions(Arrays.asList("public_profile", "email")); 
    facebookLogin.registerCallback(callbackManager, new FacebookCallback<LoginResult>() { 
     @Override 
     public void onSuccess(LoginResult loginResult) { 
      facebookLogin.setReadPermissions(Arrays.asList("public_profile", "email")); 
      GraphRequest request = GraphRequest.newMeRequest(accessToken, 
        new GraphRequest.GraphJSONObjectCallback(){ 

         @Override 
         public void onCompleted(JSONObject object, GraphResponse response) { 

          Log.d("TOP","Object = "+object.toString()); 

         } 
        }); 
      Bundle parameters = new Bundle(); 
      parameters.putString("fields", "id,name,email,gender"); 
      request.setParameters(parameters); 
      request.executeAsync(); 
      // App code 
     } 

     @Override 
     public void onCancel() { 
      // App code 
     } 

     @Override 
     public void onError(FacebookException exception) { 
      // App code 
     } 
    }); 

} 

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

@Override 
public void onDestroy() { 
    super.onDestroy(); 
    //accessTokenTracker.stopTracking(); 
    //profileTracker.stopTracking(); 
} 

} 

Answer 1

你可以嘗試創建Graph要求和我一樣：Getting email from Facebook - FB android SDK

當你Callback完成後，使用AccessToken像：loginResult.getAccessToken()

facebookLogin.registerCallback(callbackManager, new FacebookCallback<LoginResult>() { 
    @Override 
    public void onSuccess(LoginResult loginResult) { 
     facebookLogin.setReadPermissions(Arrays.asList("public_profile", "email")); 
     GraphRequest request = GraphRequest.newMeRequest(loginResult.getAccessToken(), 
       new GraphRequest.GraphJSONObjectCallback(){ 

        @Override 
        public void onCompleted(JSONObject object, GraphResponse response) { 

         Log.d("TOP","Object = "+object.toString()); 

        } 
       }); 
     Bundle parameters = new Bundle(); 
     parameters.putString("fields", "id,name,email,gender"); 
     request.setParameters(parameters); 
     request.executeAsync(); 
     // App code 
    } 

如果您想看例Json格式試試Graph Api in：Graph Api Explorer

只是試試這種方式，請與結果請！