我想在FirebaseAuth类中使用getCurrentUser方法，但是我的代码尝试在此活动中调用getCurrentUser方法，该方法不存在。 为什么会发生？如何解决该问题并获取正确的用户实例？
package com.example.android.instagramclone.Login;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.TextInputEditText;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.example.android.instagramclone.Home.HomeActivity;
import com.example.android.instagramclone.R;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
public class LoginActivity extends AppCompatActivity {
private static final String TAG = "LoginActivity";
private Context mContext = LoginActivity.this;
//Firebase
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
//personal info
private String email;
private String userName;
private String password;
private TextInputEditText mEmail;
private TextInputEditText mPassword;
//objects on the layout
private Button btnLogin;
private ProgressBar mProgressBar;
private TextView mPleaseWait;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
Log.d(TAG, "onCreate: setting up LoginActivity.");
initWidgets();
setupFirebase();
init();
}
@Override
protected void onStart() {
super.onStart();
mAuth.addAuthStateListener(mAuthListener);
}
@Override
protected void onStop() {
super.onStop();
if (mAuthListener != null) {
mAuth.removeAuthStateListener(mAuthListener);
}
}
//initialize widgets.
private void initWidgets() {
Log.d(TAG, "initWidgets: Initializing widgets.");
mProgressBar = (ProgressBar) findViewById(R.id.loginRequestLoadingProgressBar);
mPleaseWait = (TextView) findViewById(R.id.pleaseWait);
mEmail = (TextInputEditText) findViewById(R.id.input_email);
mPassword = (TextInputEditText) findViewById(R.id.input_password);
mProgressBar.setVisibility(View.GONE);
mPleaseWait.setVisibility(View.GONE);
}
private boolean isStringNull(String str) {
Log.d(TAG, "isStringNull: checking if null");
if (str.equals("") || str == null) {
return true;
} else {
return false;
}
}
/**
* -------------------- Firebase Section----------------------------------------------*
*/
private void init() {
//Login button
btnLogin = (Button) findViewById(R.id.btn_login);
//set up button Listener
btnLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d(TAG, "onClick: attempting to log in.");
//To check inputs are not null
String email = mEmail.getText().toString();
String password = mPassword.getText().toString();
//if both of them are filled out
if (isStringNull(email) || isStringNull(password)) {
Toast.makeText(mContext, "You must fill out all the fields", Toast.LENGTH_SHORT).show();
} else {
//Processing to log in
mProgressBar.setVisibility(View.VISIBLE);
mPleaseWait.setVisibility(View.VISIBLE);
//signInWithEmailAndPassword(email, password);
mAuth.signInWithEmailAndPassword(email, password)
.addOnCompleteListener(LoginActivity.this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
FirebaseUser user = mAuth.getCurrentUser();
//If log in failed.
if (!task.isSuccessful()) {
Log.w(TAG, "signInWithEmail:failed", task.getException());
Toast.makeText(mContext, "Email is not verified. \n Please check your Email.", Toast.LENGTH_SHORT).show();
mProgressBar.setVisibility(View.GONE);
mPleaseWait.setVisibility(View.GONE);
//If log in successful.
} else {
try {
//if the account is already verified
if (user.isEmailVerified()) {
Log.d(TAG, "onComplete: success. Email is verified.");
Toast.makeText(mContext, "Email is verified.", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(mContext, HomeActivity.class);
startActivity(intent);
// If the account is not verified yet.
} else {
// display a message to the user.
Log.w(TAG, "signInWithEmail:failure", task.getException());
Toast.makeText(mContext, "Authentication failed.",
Toast.LENGTH_SHORT).show();
mProgressBar.setVisibility(View.GONE);
mPleaseWait.setVisibility(View.GONE);
mAuth.signOut();
}
} catch (NullPointerException e) {
Log.d(TAG, "onComplete: NullPointerException: " + e.getMessage());
}
}
// ...
}
});
}
}
});
//Setting up the link to RegisterActivity.
TextView linkSignUp = (TextView) findViewById(R.id.link_signup);
linkSignUp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d(TAG, "onClick: navigating to register screen");
Intent intent = new Intent(mContext, RegisterActivity.class);
startActivity(intent);
}
});
//If the user is logged in, navigate the user to HomeActivity.
FirebaseUser user = mAuth.getCurrentUser();
if(user != null){
Intent intent = new Intent(LoginActivity.this, HomeActivity.class);
startActivity(intent);
finish();
}
}
/**
* setting up firebase
*/
private void setupFirebase () {
Log.d(TAG, "setupFirebase: started.");
mAuth = FirebaseAuth.getInstance();
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
Log.d(TAG, "onAuthStateChanged: sign_in");
} else {
Log.d(TAG, "onAuthStateChanged: authentification failed.");
}
}
};
}
}
这是我的gradle文件。
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.example.android.instagramclone"
minSdkVersion 16
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
//Design Library for Coodinator Layout and toolbars
//noinspection GradleCompatible
implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
//firebase
implementation 'com.google.firebase:firebase-core:16.0.1'
//design support
implementation "com.android.support:design:28.0.0"
//annotaion?
implementation 'org.jetbrains:annotations-java5:15.0'
//Resolve nullable
implementation 'com.android.support:support-annotations:+'
//circle image
implementation 'de.hdodenhof:circleimageview:2.2.0'
//universal image loader
implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.5'
//for firebase
implementation 'com.firebaseui:firebase-ui-auth:4.1.0'
// for Firebase database
implementation 'com.google.firebase:firebase-database:16.0.1'
}
apply plugin: 'com.google.gms.google-services'
身份验证成功后，我想转到HomeActivity，但这只是直接返回LoginActivity。 它没有向我显示日志中的任何错误，因此我观看了“ getCurrentUser”变量。
它说： 没有这样的实例方法：'com.example.android.instagramclone.Login.LoginActivity.getCurrentUser'
在
//If the user is logged in, navigate the user to HomeActivity.
FirebaseUser user = mAuth.getCurrentUser();
if(user != null){
Intent intent = new Intent(LoginActivity.this, HomeActivity.class);
startActivity(intent);
finish();
}
答案 0 :(得分：0)
尝试使缓存无效
从菜单File -> Invalidate Caches/ Restart-> Invalidate and Restart
答案 1 :(得分：0)
谢谢，我解决了我的问题。 我取消了“用户”以及mAuth。 另外，我发现我在HomeActivity中编写了mAuth.SignOut。 那是我的全部错误。