package com.example.yohan.facebookfirebasesdk; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; import com.facebook.login.LoginManager; import com.google.firebase.auth.FirebaseAuth; import com.google.firebase.auth.FirebaseUser; public class profile extends AppCompatActivity { Button btnFBLogout; private FirebaseAuth mAuth; TextView tvid; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_profile); btnFBLogout = findViewById(R.id.btnlogout); tvid = findViewById(R.id.tvId); mAuth = FirebaseAuth.getInstance(); FirebaseUser user = mAuth.getCurrentUser(); //String id = user. // tvid.setText(id); btnFBLogout.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { mAuth.signOut();//firebase LoginManager.getInstance().logOut();//facebook updateUI(); } }); } @Override protected void onStart() { super.onStart(); FirebaseUser user = mAuth.getCurrentUser(); if(user == null){ updateUI(); } } private void updateUI() { Toast.makeText(profile.this,"you are logout!",Toast.LENGTH_LONG).show(); Intent i = new Intent(profile.this,MainActivity.class); startActivity(i); finish(); } }