如何使用Facebook SDK在Android應用程序中制作

Question

我試圖使我的應用程序中的按鈕變得簡單。 Ive已經制作了一個可以使用的分享按鈕，我希望對帖子發表點贊。

正在編寫以下代碼：

public class MainFragment extends Fragment {
private UiLifecycleHelper uiHelper;
 TextView tv1;
 TextView tv2;
 Button btn;
 Button btnLike;
 ProfilePictureView profilePictureView ;
 String like="";
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    uiHelper = new UiLifecycleHelper(getActivity(), callback);
    uiHelper.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

      View view = inflater.inflate(R.layout.activity_main, container, false);
      tv1=(TextView) view.findViewById(R.id.textView1);
      tv2=(TextView) view.findViewById(R.id.textView2);
      btn=(Button) view.findViewById(R.id.button1);
      btnLike=(Button) view.findViewById(R.id.button2);
      btn.setOnClickListener(shareListener);
      btnLike.setOnClickListener(likeListener);
      profilePictureView =(ProfilePictureView) view.findViewById(R.id.selection_profile_pic);
      profilePictureView.setCropped(true);
      LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);    
      authButton.setReadPermissions(Arrays.asList("user_likes", "user_status","public_profile"));
      //authButton.setPublishPermissions(Arrays.asList("publish_action"));
      authButton.setFragment(this);
    return view;
}

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

    }

     else if (state.isClosed()) {
        Log.i("log out", "Logged out...");
        tv1.setText("");
        tv2.setText("");
    }
}

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

@Override
public void onResume() {
    super.onResume();
    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 makeMeRequest(final Session session) {
    // Make an API call to get user data and define a 
    // new callback to handle the response.
    Request request = Request.newMeRequest(session, 
            new Request.GraphUserCallback() {
        @Override
        public void onCompleted(GraphUser user, Response response) {
            // If the response is successful
            if (session == Session.getActiveSession()) {
                if (user != null) {
                    // Set the id for the ProfilePictureView
                      profilePictureView.setProfileId(user.getId());
                    // view that in turn displays the profile picture.                  
                    tv1.setText(user.getFirstName().toString()+"");
                    // Set the Textview's text to the user's name.                 
                    tv2.setText(user.getLastName().toString());
                }
            }
            if (response.getError() != null) {
                // Handle errors, will do so later.
            }
        }
    });
    request.executeAsync();
} 
private OnClickListener shareListener=new OnClickListener() {

    @Override
    public void onClick(View v) {
        Session session = Session.getActiveSession();
        if (session != null && session.isOpened()) {
        publishFeedDialog();
        Bundle params = new Bundle();
        params.putString("object", "http://samples.ogp.me/<699966466709368>");

        Request request = new Request(
            Session.getActiveSession(),
            "me/og.likes",
            params,
            HttpMethod.POST
        );
        Response response = request.executeAndWait();
        // handle the response
        }
        else{
            Toast.makeText(getActivity(), "you must log in first", 1500).show();
        }

    }
};

private OnClickListener likeListener=new OnClickListener() {

    @Override
    public void onClick(View v) {
        Session session = Session.getActiveSession();
        if (session != null && session.isOpened()) {
             Request likeRequest = new Request(Session.getActiveSession(),"/{"+ like.toString() +"}/likes", null, HttpMethod.POST, new Request.Callback() {

                 @Override
                 public void onCompleted(Response response) {
                        Log.i("like", response.toString());

                 }
        });
        Request.executeBatchAndWait(likeRequest);
        }

    }
};  



private void publishFeedDialog() {
    Bundle params = new Bundle();
    params.putString("name", "aaa");
    params.putString("caption", "bbb");
    params.putString("description", "ccc");
    params.putString("link", "https://developers.facebook.com/android");
    params.putString("picture", "https://raw.github.com/fbsamples/ios-3.x-howtos/master/Images/iossdk_logo.png");

    WebDialog feedDialog = (
        new WebDialog.FeedDialogBuilder(getActivity(),
            Session.getActiveSession(),
            params))
        .setOnCompleteListener(new OnCompleteListener() {

            @Override
            public void onComplete(Bundle values,
                FacebookException error) {
                if (error == null) {
                    // When the story is posted, echo the success
                    // and the post Id.
                    final String postId = values.getString("post_id");
                    if (postId != null) {
                        Toast.makeText(getActivity(),
                            "Posted story, id: "+postId,
                            Toast.LENGTH_SHORT).show();
                        like=postId;
                    } else {
                        // User clicked the Cancel button
                        Toast.makeText(getActivity().getApplicationContext(), 
                            "Publish cancelled", 
                            Toast.LENGTH_SHORT).show();
                    }
                } else if (error instanceof FacebookOperationCanceledException) {
                    // User clicked the "x" button
                    Toast.makeText(getActivity().getApplicationContext(), 
                        "Publish cancelled", 
                        Toast.LENGTH_SHORT).show();
                } else {
                    // Generic, ex: network error
                    Toast.makeText(getActivity().getApplicationContext(), 
                        "Error posting story", 
                        Toast.LENGTH_SHORT).show();
                }
            }

        })
        .build();
    feedDialog.show();
}

}

但是什么都沒發生..我進入logcat這個錯誤：

{Response:  responseCode: 200, graphObject: null, error: {HttpStatus: -1, errorCode: -1, errorType: null, errorMessage: java.lang.NullPointerException}, isFromCache:false}

有些人知道如何修復它並在我的應用上創建一個“贊”按鈕？

Answer 1

我建議您使用此庫（ 此處有詳細信息 ）：

dependencies {
    compile 'com.shamanland:facebook-like-button:0.1.8'
}

該庫允許您使用“喜歡”，“共享”和“推薦”按鈕的不同布局。 它還使用WebView和基於<iframe>的facebook插件實現“喜歡”操作。

看截圖：

Answer 2

您在哪里填充like變量？ 您是否已閱讀https://developers.facebook.com/docs/graph-api/reference/v2.0/object/likes#publish作為參考？