Android 接入Facebook实现第三方登陆教程（精简版）

首先需要在Facebook官方注册你的应用，这个不用说，需要注意的是在创建应用的时候需要填写应用的key hashes ，这个可以用cmd命令获取，也可以用代码动态获取，我是用代码动态获取的，下面贴下方法：

// Add code to print out the key hash
    @SuppressLint("NewApi")
    private fun getKeyHashValue() {
        try {
            val info = activity!!.getPackageManager().getPackageInfo(
                    "com.wj.demo",
                    PackageManager.GET_SIGNATURES)
            for (signature in info.signatures) {
                val md = MessageDigest.getInstance("SHA")
                md.update(signature.toByteArray())
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT))
            }
        } catch (e: PackageManager.NameNotFoundException) {
            Log.d("KeyHash:",e.toString())
        } catch (e: NoSuchAlgorithmException) {
            Log.d("KeyHash:", e.toString())
        }

    }

然后把打印出来的字符串填写到Facebook开发者后台的key Hashes里面就可以了

然后开始在项目里面集成sdk和初始化sdk，调用登陆方法进行登陆：
在project级别的目录下的build.gradle文件种配置

repositories {
        mavenCentral()
    }

在app级别的目录下的build.gradle文件种配置sdk依赖：

  compile 'com.facebook.android:facebook-android-sdk:4.6.0'

在清单文件种配置下面：

<meta-data
        android:name="com.facebook.sdk.ApplicationId"
        android:value="@string/facebook_app_id" />

        <provider
            android:name="com.facebook.FacebookContentProvider"
            android:authorities="com.facebook.app.FacebookContentProvider5555302316225142"
            android:exported="true" />

        <activity
            android:name="com.facebook.FacebookActivity"
            android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
            android:label="@string/app_name" />

在application种初始化sdk：

 FacebookSdk.sdkInitialize(applicationContext)

写登陆的关键代码，我这里整理到了工具类种FaceBookLoginUtil.kt：

import android.annotation.SuppressLint
import android.app.Activity
import android.content.pm.PackageManager
import android.os.Bundle
import android.util.Log
import android.util.Base64
import com.facebook.*
import com.facebook.login.LoginManager
import com.facebook.login.LoginResult
import org.json.JSONObject
import java.security.MessageDigest
import java.security.NoSuchAlgorithmException
import java.util.*


/**
 * @Description:  facebook 登陆二次封装
 * @Author: wjj
 * @Time:   2018/6/26 15:24
 */
class FaceBookLoginUtil {

    val TAG = "FaceBookLoginUtil"

    var activity: Activity? = null

    var loginManager: LoginManager? = null

    var call: CallbackManager? = null

    var loginListener:FacebookListener? = null

    var mName :String = ""
    var mPhoto :String = ""

    var mYear :String = "0"
    var mMonth :String = "0"
    var mDay :String = "0"

    /*初始化*/
    constructor(activity: Activity, loginListener: FacebookListener) {
        this.activity = activity
        this.loginListener = loginListener
        getKeyHashValue()
        //初始化facebook登录服务
        call = CallbackManager.Factory.create()
        loginManager = LoginManager.getInstance()
        loginManager?.registerCallback(call,
                object : FacebookCallback<LoginResult> {
                    override fun onSuccess(loginResult: LoginResult) {
                        Log.e(TAG, "onSuccess")
                        var accessToken = loginResult.getAccessToken()
                        userInfo(accessToken)
                    }

                    override fun onCancel() {
                        Log.e(TAG, "onCancel")
                        loginListener.onCancel()
                    }

                    override fun onError(exception: FacebookException) {
                        Log.e(TAG, "onError")
                        loginListener.onError()
                    }
                })
    }

    // Add code to print out the key hash
    @SuppressLint("NewApi")
    private fun getKeyHashValue() {
        try {
            val info = activity!!.getPackageManager().getPackageInfo(
                    "com.wj.demo",
                    PackageManager.GET_SIGNATURES)
            for (signature in info.signatures) {
                val md = MessageDigest.getInstance("SHA")
                md.update(signature.toByteArray())
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT))
            }
        } catch (e: PackageManager.NameNotFoundException) {
            Log.d("KeyHash:",e.toString())
        } catch (e: NoSuchAlgorithmException) {
            Log.d("KeyHash:", e.toString())
        }

    }

    //登陆
    fun login() {
        loginManager?.logInWithReadPermissions(activity, Arrays.asList("public_profile", "user_friends", "user_status", "user_birthday", "user_location", "user_hometown"))
    }


    //登出
    fun logout() {
        loginManager!!.logOut()
    }


    fun getCallbackManager(): CallbackManager {
        return this!!.call!!
    }

    /*获取个人信息*/
    fun userInfo(accessToken: AccessToken) {

        var request = GraphRequest.newMeRequest(accessToken, object : GraphRequest.GraphJSONObjectCallback {
            override fun onCompleted(obj: JSONObject?, response: GraphResponse?) {
                //获取个人信息
                val facebook_name = obj?.optString("name")
                //生日
                val facebook_birthday = (obj?.optString("birthday").toString()).replace("/", "", true).trim()
                if (facebook_birthday.length!=0){

                    mDay = facebook_birthday.substring(0, 2)
                    mMonth = facebook_birthday.substring(2, 4)
                    mYear = facebook_birthday.substring(4, 8)
                }

                //获取用户头像
                val object_pic = obj?.optJSONObject("picture")
                val object_data = object_pic?.optJSONObject("data")
                val facebook_photo = object_data?.optString("url")

                mName = facebook_name!!
                mPhoto = facebook_photo!!

                SharedPreferencesUnitls.setParam(activity,"name",mName)
                SharedPreferencesUnitls.setParam(activity,"mPhoto",mPhoto)
                SharedPreferencesUnitls.setParam(activity, "comeTimeY", mYear)
                SharedPreferencesUnitls.setParam(activity, "comeTimeM", mMonth)
                SharedPreferencesUnitls.setParam(activity, "comeTimeD", mDay)


                loginListener?.onSuccess()
            }

        })
        var parameters = Bundle()
        parameters.putString("fields", "id,name,link,gender,birthday,email,picture,locale,updated_time,timezone,age_range,first_name,last_name")
        request.parameters = parameters
        request.executeAsync()
    }



    interface FacebookListener{
        fun onSuccess()
        fun onCancel()
        fun onError()
    }


}

然后调用关键代码：

class LoginActivity:Activity(){

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_login)   
      faceBookLoginUtil = FaceBookLoginUtil(this, object : FaceBookLoginUtil.FacebookListener {
            override fun onSuccess() {
                Toast.makeText(this@LoginActivity, "login success", Toast.LENGTH_SHORT).show()
                var intent = Intent(this@LoginActivity,HomeActivity().javaClass)
                startActivity(intent)
                finish()
            }

            override fun onCancel() {
                Toast.makeText(this@LoginActivity, "Cancel the login", Toast.LENGTH_SHORT).show()
            }

            override fun onError() {
                Toast.makeText(this@LoginActivity, "Loading failure", Toast.LENGTH_SHORT).show()
            }
        })


         //点击登陆的按钮后调用fb登陆
                faceBookLoginUtil?.login()

    }


}