dependencies {
    implementation 'com.facebook.android:facebook-android-sdk:6.4.0'
}

<com.facebook.login.widget.LoginButton
    android:id="@+id/login_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginBottom="326dp"
    android:layout_gravity="center_horizontal"
    android:text="登录到Facebook"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="1.0"
    app:layout_constraintWidth_default="wrap" />

package com.example.facebook_sdk_demo;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.Facebook;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.login.LoginManager;
import com.facebook.login.LoginResult;

import java.util.Arrays;

public class MainActivity extends AppCompatActivity {

    private CallbackManager mCallbackManager;
    private Facebook mFacebook;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 初始化Facebook SDK
        mFacebook = Facebook.createInstance(this, Arrays.asList(Facebook.DEFAULT_ADD_YOUR_CREDITS_KEY));
        mCallbackManager = CallbackManager.Factory.create();

        // 登录按钮点击事件
        Button loginButton = findViewById(R.id.login_button);
        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                loginToFacebook();
            }
        });
    }

    private void loginToFacebook() {
        LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile", "email"));
    }

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

    public void shareFacebook(String message) {
        if (mFacebook != null) {
            Bundle params = new Bundle();
            params.putString("message", message);
            mFacebook.share(params);
        }
    }
}

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

// 初始化Facebook SDK

mFacebook = Facebook.createInstance(this, Arrays.asList(Facebook.DEFAULT_ADD_YOUR_CREDITS_KEY));

mCallbackManager = CallbackManager.Factory.create();

// 登录按钮点击事件

Button loginButton = findViewById(R.id.login_button);

loginButton.setOnClickListener(new View.OnClickListener() {

    @Override

    public void onClick(View v) {

        loginToFacebook();

    }

});

// 分享按钮点击事件

Button shareButton = findViewById(