java - 如何在 Android Facebook 应用程序成功登录后启动新 Activity 并 Conceal 登录页面并在新页面上获取注销按钮

Question

我正在将 facebook 应用程序与我的 android 应用程序集成，并且我不想执行 android facebook 应用程序的默认行为，即成功登录后我不想返回同一登录页面并在那里获得注销按钮。成功登录后，它会快速启动一个带有注销按钮的新 Activity ，并且从登录返回时不会出现登录页面。这是我的主要 Activity Java 类代码:

package com.example.facebook;

import java.util.Arrays;
import java.util.List;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
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 FragmentActivity {

    private LoginButton loginBtn;
    private Button postImageBtn;
    private Button updateStatusBtn;

    private TextView userName;

    private UiLifecycleHelper uiHelper;

    private static final List<String> PERMISSIONS = Arrays.asList("publish_actions");

    private static String message = "Sample status posted from android app";
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        
        uiHelper = new UiLifecycleHelper(this, statusCallback);
        uiHelper.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
    
    

        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);
    }

    private Session.StatusCallback statusCallback = new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state,
                Exception exception) {
            if (state.isOpened()) {
                buttonsEnabled(true);
                 if (Session.getActiveSession() != null || Session.getActiveSession().isOpened()){
                     Intent i = new Intent(MainActivity.this,nextscreen.class);
                    startActivity(i);
                }
        
        
                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();
    }
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        uiHelper.onActivityResult(requestCode, resultCode, data);
    //  Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
        // if (Session.getActiveSession() != null || Session.getActiveSession().isOpened()){
         //    Intent i = new Intent(MainActivity.this,nextscreen.class);
          //  startActivity(i);
      //  }
        
        
        
    }
    

    @Override
    public void onSaveInstanceState(Bundle savedState) {
        super.onSaveInstanceState(savedState);
        uiHelper.onSaveInstanceState(savedState);
    }

}

在 if (state.isOpened()) 方法中应用 Activity(intent) 后，它会在登录页面上返回一段时间的注销按钮，然后自己跳转到一个新 Activity 。但我不想要这样。我想返回一个带有注销按钮的新 Activity ，并且不想再次显示登录页面，并且在单击新 Activity 上的注销按钮时，我想要登录页面。

Answer 1

如果您成功登录，则有 Facebook 登录按钮。它将把措辞从“登录 Facebook”更改为“注销”。如果您不想看到它，只需将 Visibility GONE 或 Intent 设置为所需的 Activity 即可。如果您使用 Intent ，请设置如下标志

Intent next = new Intent(getApplicationContext(), MenuActivity.class);
next.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(next);

下面是facebook登录按钮的例子

loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {

            @Override
            public void onSuccess(LoginResult loginResult) {
                GraphRequest request = GraphRequest.newMeRequest(AccessToken.getCurrentAccessToken(), (object, response) -> {
                    // hide this facebook login button
                    // Intent to your desired activity

                });
                Bundle parameters = new Bundle();
                parameters.putString("fields", "id,name,email,birthday,gender,first_name,last_name");
                request.setParameters(parameters);
                request.executeAsync();
            }

            @Override
            public void onCancel() {
                Toast.makeText(getApplicationContext(), Message.LOGINCANCEL, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onError(FacebookException e) {
                Toast.makeText(getApplicationContext(), Message.LOGINFAILED, Toast.LENGTH_SHORT).show();
            }
        });

如果您想将 Facebook 的“注销”按钮更改为“登录 Facebook”，请使用以下代码。只需创建 BUTton 并执行 onClick() 即可触发以下代码

if (AccessToken.getCurrentAccessToken() != null && com.facebook.Profile.getCurrentProfile() != null){
    LoginManager.getInstance().logOut();
}