В методе onResume(), когда я ставлю mFirebaseAuth.addAuthStateListener(mAuthStateListener);, это вызывает, к сожалению, остановку при установке приложения.Если я удаляю оператор, он работает хорошо, но не показывает опцию входа.Как я могу преодолеть эту ошибку и показать опцию входа в моем приложении?Код указан ниже:
package com.google.firebase.udacity.friendlychat;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.text.Editable;
import android.text.InputFilter;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.Toast;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.firebase.ui.auth.AuthUI;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
public static final String ANONYMOUS = "anonymous";
public static final int DEFAULT_MSG_LENGTH_LIMIT = 1000;
public static final int RC_SIGN_IN = 1;
private ListView mMessageListView;
private MessageAdapter mMessageAdapter;
private ProgressBar mProgressBar;
private ImageButton mPhotoPickerButton;
private EditText mMessageEditText;
private Button mSendButton;
private String mUsername;
//variables for read and write data from firebase
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mMessageDatabaseReference;
private ChildEventListener mChildEventListener;
private FirebaseAuth mFirebaseAuth;
private FirebaseAuth.AuthStateListener mAuthStateListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Initialize Realtime database & database Reference
mFirebaseDatabase=FirebaseDatabase.getInstance();
mFirebaseAuth=FirebaseAuth.getInstance();
mMessageDatabaseReference=mFirebaseDatabase.getReference().child("messages");
mUsername = ANONYMOUS;
// Initialize references to views
mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
mMessageListView = (ListView) findViewById(R.id.messageListView);
mPhotoPickerButton = (ImageButton) findViewById(R.id.photoPickerButton);
mMessageEditText = (EditText) findViewById(R.id.messageEditText);
mSendButton = (Button) findViewById(R.id.sendButton);
// Initialize message ListView and its adapter
List<FriendlyMessage> friendlyMessages = new ArrayList<>();
mMessageAdapter = new MessageAdapter(this, R.layout.item_message, friendlyMessages);
mMessageListView.setAdapter(mMessageAdapter);
// Initialize progress bar
mProgressBar.setVisibility(ProgressBar.INVISIBLE);
// ImagePickerButton shows an image picker to upload a image for a message
mPhotoPickerButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// TODO: Fire an intent to show an image picker
}
});
// Enable Send button when there's text to send
mMessageEditText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
if (charSequence.toString().trim().length() > 0) {
mSendButton.setEnabled(true);
} else {
mSendButton.setEnabled(false);
}
}
@Override
public void afterTextChanged(Editable editable) {
}
});
mMessageEditText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(DEFAULT_MSG_LENGTH_LIMIT)});
// Send button sends a message and clears the EditText
mSendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// TODO: Send messages on click
// Clear input box
mMessageEditText.setText("");
}
});
//Send button activity set
mSendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FriendlyMessage friendlyMessage=new FriendlyMessage(mMessageEditText.getText()
.toString(),mUsername,null);
mMessageDatabaseReference.push().setValue(friendlyMessage);
mMessageEditText.setText("");
}
});
//Child event listener for write data from database********************
mChildEventListener=new ChildEventListener() {
@Override
public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
FriendlyMessage friendlyMessage= dataSnapshot.getValue(FriendlyMessage.class);
mMessageAdapter.add(friendlyMessage);
}
@Override
public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
};
mMessageDatabaseReference.addChildEventListener(mChildEventListener);
mAuthStateListener=new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user=firebaseAuth.getCurrentUser();
if(user !=null){
//sign in code
Toast.makeText(MainActivity.this,"Welcome,you are successfully logged in.",Toast.LENGTH_LONG).show();
}
else{
//sign out code
startActivityForResult(
AuthUI.getInstance()
.createSignInIntentBuilder()
.setIsSmartLockEnabled(false)
.setProviders(
AuthUI.EMAIL_PROVIDER,
AuthUI.GOOGLE_PROVIDER)
.build(),
RC_SIGN_IN);
}
}
};
//*************************************************************************
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}
@Override
protected void onResume(){
super.onResume();
mFirebaseAuth.addAuthStateListener(mAuthStateListener);
}
@Override
protected void onPause() {
super.onPause();
if(mAuthStateListener!=null){
mFirebaseAuth.removeAuthStateListener(mAuthStateListener);
}
}
}