在Android应用程序中集成Facebook

Question

我已按照以下步骤整合来自https://developers.facebook.com/docs/android/getting-started的facebook应用程序，但我无法获取结果，因为应用程序在我的设备中启动，并在几秒钟内返回到MainActivity页面而不是去facebook登录。

请在下面找到我的MainActivity.java文件中的代码。

package com.testloginfb;


import com.facebook.*;  
import com.facebook.model.*;

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

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.graphics.Bitmap;  
import android.graphics.BitmapFactory;  
import android.os.Bundle;  
import android.support.v4.app.FragmentActivity;  
import android.util.Base64;  
import android.util.Log;   
import android.view.View;   
import android.view.View.OnClickListener;   
import android.widget.Button;  
import android.widget.TextView;  
import android.widget.Toast;

import com.facebook.Request;  
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 com.facebook.widget.LoginButton.UserInfoChangedCallback;   

public class MainActivity extends Activity {


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

        //uiHelper = new UiLifecycleHelper(this, statusCallback);
        //uiHelper.onCreate(savedInstanceState);
        //showHashKey(this);
        setContentView(R.layout.activity_main);
        try
        {
        //Start Facebook login
        Session.openActiveSession(this, true, new Session.StatusCallback() {

            @Override
            public void call(Session session, SessionState state,
                    Exception exception)
            {
                // TODO Auto-generated method stub
                if (session.isOpened())
                {
                    Request.newMeRequest(session, new Request.GraphUserCallback() 
                    {
                        public void onCompleted(GraphUser user, Response response) 
                        {
                            if(user != null)
                            {
                                TextView welcome = (TextView) findViewById(R.id.welcome);
                                welcome.setText("Hello " + user.getName() + "!" );

                            }
                        }
                    }).executeAsync();
                }

            }

        });

        }
        catch(NullPointerException e)
        {
            e.printStackTrace();
        }


    }
        /*userName = (TextView) findViewById(R.id.user_name);
        loginBtn = (LoginButton) findViewById(R.id.fb_login_button);
        loginBtn.setUserInfoChangedCallback(new UserInfoChangedCallback() {
            @Override
            public void onUserInfoFetched(GraphUser user) {
                if (user != null) {

                    userName.setText("Hello, " + user.getName());
                } else {
                    userName.setText("You are not logged");
                }
            }
        });

        postImageBtn = (Button) findViewById(R.id.post_image);
        postImageBtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View view) {
                postImage();
            }
        });

        updateStatusBtn = (Button) findViewById(R.id.update_status);
        updateStatusBtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

            }
        });

        buttonsEnabled(false);
    }*/

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
        Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
    }

    /*public static void showHashKey(Context context) {
        System.out.println("HI");
        try {
            PackageInfo info = context.getPackageManager().getPackageInfo(
                    "com.testloginfb", PackageManager.GET_SIGNATURES); //Your package name here
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                System.out.println("KeyHash:"+Base64.encodeToString(md.digest(), Base64.DEFAULT));
                }
        } catch (NameNotFoundException e) {
            System.out.println(e);
        } catch (NoSuchAlgorithmException e) {
            System.out.println(e);
        }
    }

    private Session.StatusCallback statusCallback = new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state,
                Exception exception) {
            if (state.isOpened()) {
                buttonsEnabled(true);
                Log.d("FacebookSampleActivity", "Facebook session opened");
            } else if (state.isClosed()) {
                buttonsEnabled(false);
                Log.d("FacebookSampleActivity", "Facebook session closed");
            }
        }
    };

    public void buttonsEnabled(boolean isEnabled) {
        postImageBtn.setEnabled(isEnabled);
        updateStatusBtn.setEnabled(isEnabled);
    }

    public void postImage() {
        if (checkPermissions()) {
            Bitmap img = BitmapFactory.decodeResource(getResources(),
                    R.drawable.ic_launcher);
            Request uploadRequest = Request.newUploadPhotoRequest(
                    Session.getActiveSession(), img, new Request.Callback() {
                        @Override
                        public void onCompleted(Response response) {
                            Toast.makeText(MainActivity.this,
                                    "Photo uploaded successfully",
                                    Toast.LENGTH_LONG).show();
                        }
                    });
            uploadRequest.executeAsync();
        } else {
            requestPermissions();
        }
    }

    public void postStatusMessage() {
        if (checkPermissions()) {
            Request request = Request.newStatusUpdateRequest(
                    Session.getActiveSession(), message,
                    new Request.Callback() {
                        @Override
                        public void onCompleted(Response response) {
                            if (response.getError() == null)
                                Toast.makeText(MainActivity.this,
                                        "Status updated successfully",
                                        Toast.LENGTH_LONG).show();
                        }
                    });
            request.executeAsync();
        } else {
            requestPermissions();
        }
    }

    public boolean checkPermissions() {
        Session s = Session.getActiveSession();
        if (s != null) {
            return s.getPermissions().contains("publish_actions");
        } else
            return false;
    }

    public void requestPermissions() {
        Session s = Session.getActiveSession();
        if (s != null)
            s.requestNewPublishPermissions(new Session.NewPermissionsRequest(
                    this, PERMISSIONS));
    }

    @Override
    public void onResume() {
        super.onResume();
        uiHelper.onResume();
        buttonsEnabled(Session.getActiveSession().isOpened());
    }

    @Override
    public void onPause() {
        super.onPause();
        uiHelper.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        uiHelper.onDestroy();
    }


    enter code here
    @Override
    public void onSaveInstanceState(Bundle savedState) {
        super.onSaveInstanceState(savedState);
        uiHelper.onSaveInstanceState(savedState);
    }
*/
}