列表<GraphUser>用戶爲空

Question

我想獲取當前登錄用戶的朋友列表。

以下是我想獲得它：

private void fetchFriends(Session session) { 
      Request.newMyFriendsRequest(session, new GraphUserListCallback() { 

       @Override 
       public void onCompleted(List<GraphUser> users, Response response) { 
        if (users != null) { 
         friendsList = new ArrayList<FriendInfoHolder>(); 
         for (GraphUser u : users) { 
          friendsList.add(buildFriendInfoHolder(u)); 
         } 

         Intent intent = new Intent(parentActivity, 
           FriendListActivity.class); 
         intent.putParcelableArrayListExtra("friends_list", 
           friendsList); 
         parentActivity.startActivity(intent); 
        } else { 
         Log.i("users_status", "null"); 
        } 
       } 
      }).executeAsync(); 
} 

的問題是用戶列表（List<GraphUser> users）總是空。

我先前設置的讀取權限如下：

authButton.setReadPermissions(Arrays.asList("read_friendlists")); 

所以，我不知道什麼是錯的。這裏是完整的代碼：

解決：我沒有在清單文件中添加INTERNET權限。

package home.example.logintest; 

import java.security.MessageDigest; 
import java.security.NoSuchAlgorithmException; 
import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.List; 

import com.facebook.Request; 
import com.facebook.Request.GraphUserListCallback; 
import com.facebook.Response; 
import com.facebook.Session; 
import com.facebook.SessionState; 
import com.facebook.UiLifecycleHelper; 
import com.facebook.model.GraphUser; 
import com.facebook.widget.LoginButton; 

import android.os.Bundle; 
import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.content.pm.PackageInfo; 
import android.content.pm.PackageManager; 
import android.content.pm.PackageManager.NameNotFoundException; 
import android.content.pm.Signature; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentActivity; 
import android.util.Base64; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.View; 
import android.view.ViewGroup; 

public class MainActivity extends FragmentActivity { 

    private MainFragement mainFragement; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     if (savedInstanceState == null) { 
      // Add the fragment on initial activity setup 
      mainFragement = new MainFragement(); 
      mainFragement.setParentActivity(this); 

      getSupportFragmentManager().beginTransaction() 
        .add(android.R.id.content, mainFragement).commit(); 
     } else { 
      // Or set the fragment from restored state info 
      mainFragement = (MainFragement) getSupportFragmentManager() 
        .findFragmentById(android.R.id.content); 
     } 

     // try { 
     // PackageInfo info = getPackageManager().getPackageInfo(
     // "home.example.logintest", PackageManager.GET_SIGNATURES); 
     // for (Signature signature : info.signatures) { 
     // MessageDigest md = MessageDigest.getInstance("SHA"); 
     // md.update(signature.toByteArray()); 
     // Log.d("KeyHash:", 
     // Base64.encodeToString(md.digest(), Base64.DEFAULT)); 
     // } 
     // } catch (NameNotFoundException e) { 
     // 
     // } catch (NoSuchAlgorithmException e) { 
     // 
     // } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    public static class MainFragement extends Fragment { 
     private UiLifecycleHelper uiHelper; 
     private ArrayList<FriendInfoHolder> friendsList; 
     private Activity parentActivity; 

     public Activity getParentActivity() { 
      return parentActivity; 
     } 

     public void setParentActivity(Activity parentActivity) { 
      this.parentActivity = parentActivity; 
     } 

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

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
       Bundle savedInstanceState) { 
      View view = inflater.inflate(R.layout.activity_main, container, 
        false); 

      LoginButton authButton = (LoginButton) view 
        .findViewById(R.id.authButton); 
      authButton.setFragment(this); 

      authButton.setReadPermissions(Arrays.asList("read_friendlists")); 

      return view; 
     } 

     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 

      uiHelper = new UiLifecycleHelper(getActivity(), callback); 
      uiHelper.onCreate(savedInstanceState); 
     } 

     @Override 
     public void onResume() { 
      super.onResume(); 

      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); 
     } 

     private void onSessionStateChange(Session session, SessionState state, 
       Exception exception) { 
      if (state.isOpened()) { 
       Log.i("msg", "Logged in..."); 

       fetchFriends(session); 

      } else if (state.isClosed()) { 
       Log.i("msg", "Logged out..."); 
      } 
     } 

     private void fetchFriends(Session session) { 
      Request.newMyFriendsRequest(session, new GraphUserListCallback() { 

       @Override 
       public void onCompleted(List<GraphUser> users, Response response) { 
        if (users != null) { 
         friendsList = new ArrayList<FriendInfoHolder>(); 
         for (GraphUser u : users) { 
          friendsList.add(buildFriendInfoHolder(u)); 
         } 

         Intent intent = new Intent(parentActivity, 
           FriendListActivity.class); 
         intent.putParcelableArrayListExtra("friends_list", 
           friendsList); 
         parentActivity.startActivity(intent); 
        } else { 
         Log.i("users_status", "null"); 
        } 
       } 
      }).executeAsync(); 
     } 

     private FriendInfoHolder buildFriendInfoHolder(GraphUser user) { 
      String profilePictureUrl = "graph.facebook.com/" + user.getId() 
        + "/picture?type=square"; 

      return new FriendInfoHolder(user.getFirstName(), 
        user.getLastName(), profilePictureUrl); 
     } 
    } 
} 

Answer 1

問題是，我沒有在清單文件中添加INTERNET權限。