我对Android Studio和Firebase还是比较陌生。我已经完成设置并连接到Firebase，但是此错误不断弹出，导致应用崩溃：
--------- beginning of crash
2019-01-17 14:38:11.420 10795-10795/com.example.asus.cab E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.asus.cab, PID: 10795
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.asus.cab/com.example.asus.cab.DriverLoginRegisterActivity}: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.example.asus.cab. Make sure to call FirebaseApp.initializeApp(Context) first.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2902)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3037)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1797)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6642)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.example.asus.cab. Make sure to call FirebaseApp.initializeApp(Context) first.
at com.google.firebase.FirebaseApp.getInstance(com.google.firebase:firebase-common@@16.0.4:240)
at com.google.firebase.auth.FirebaseAuth.getInstance(Unknown Source:1)
at com.example.asus.cab.DriverLoginRegisterActivity.onCreate(DriverLoginRegisterActivity.java:45)
at android.app.Activity.performCreate(Activity.java:7131)
at android.app.Activity.performCreate(Activity.java:7122)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2882)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3037)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1797)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6642)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
我也像这样初始化Firebase身份验证，mAuth = FirebaseAuth.getInstance（）;但我仍然遇到相同的错误
我还包括了依赖项
classpath 'com.google.gms:google- services:4.1.0'和插件
apply plugin: 'com.google.gms.google-services'大多数解决方案中都提到了这些，但是似乎没有任何作用这是下面的代码，根据日志记录，第48行中的错误指向mAuth = FirebaseAuth.getInstance（）;
public class DriverLoginRegisterActivity extends AppCompatActivity {
private Button DriverLoginButton;
private Button DriverRegisterButton;
private TextView DriverRegisterLink;
private TextView DriverStatus;
private EditText EmailDriver;
private EditText PasswordDriver;
private ProgressDialog loadingBar;
private FirebaseAuth mAuth;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_driver_login_register);
DriverLoginButton = (Button) findViewById(R.id.driver_login_btn);
DriverRegisterButton = (Button) findViewById(R.id.driver_register_btn);
DriverRegisterLink = (TextView) findViewById(R.id.register_driver_link);
DriverStatus = (TextView) findViewById(R.id.driver_status);
EmailDriver = (EditText) findViewById(R.id.email_driver);
PasswordDriver = (EditText) findViewById(R.id.password_driver);
loadingBar = new ProgressDialog(this);
// Initialize Firebase Auth
mAuth = FirebaseAuth.getInstance();
DriverRegisterButton.setVisibility(View.INVISIBLE);
DriverRegisterButton.setEnabled(false);
DriverRegisterLink.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
DriverLoginButton.setVisibility(View.INVISIBLE);
DriverRegisterLink.setVisibility(View.INVISIBLE);
DriverStatus.setText("Register Driver");
DriverRegisterButton.setVisibility(View.VISIBLE);
DriverLoginButton.setEnabled(true);
}
});
DriverRegisterButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view)
{
String email = EmailDriver.getText().toString();
String password = PasswordDriver.getText().toString();
RegisterDriver(email, password);
}
});
}
private void RegisterDriver(String email, String password) {
if (TextUtils.isEmpty(email)) {
Toast.makeText(DriverLoginRegisterActivity.this, "Please Enter Email..", Toast.LENGTH_SHORT).show();
}
if (TextUtils.isEmpty(password)) {
Toast.makeText(DriverLoginRegisterActivity.this, "Please Enter Password..", Toast.LENGTH_SHORT).show();
} else {
loadingBar.setTitle("Driver Registration");
loadingBar.setMessage("Please wait...");
loadingBar.show();
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
Toast.makeText(DriverLoginRegisterActivity.this, "Driver Register Succesful..", Toast.LENGTH_SHORT).show();
loadingBar.dismiss();
} else {
Toast.makeText(DriverLoginRegisterActivity.this, "Registration Unsuccessful, Please Try Again..", Toast.LENGTH_SHORT).show();
loadingBar.dismiss();
}
}
});
}
}
}
答案 0 :(得分：1)
确保您遵循firebase文档的每个步骤：
Firebase documentation on auth
您需要将Google服务添加到您的项目级Gradle文件：
classpath 'com.google.gms:google-services:4.2.0'
您需要将firebase核心依赖项添加到您的应用程序级别gradle文件中：
implementation 'com.google.firebase:firebase-core:16.0.6'
确保在控制台的登录方法下启用了auth选项
答案 1 :(得分：0)
您的logcat本身可以解决您的问题：
您需要在应用程序类中调用 FirebaseApp.initializeApp（Context）。
答案 2 :(得分：0)
您收到此错误是因为在您的代码中，您尚未初始化Firebase。
只需将其添加到活动的on create方法中
FirebaseApp.initializeApp(this);
mAuth = FirebaseAuth.getInstance();
答案 3 :(得分：0)
也正如先前的人所指出的那样，该错误表明您错过了调用FirebaseApp.initializeApp（Context）方法或顺序不正确。
使用Firebase Auth SDK已有最新更新，新方法非常简单且代码最少。有关更多详细信息，请参见此处https://firebase.google.com/docs/auth/android/firebaseui
这是设置身份验证提供程序和启动身份验证意图的方法。您需要为Callaback处理和UI自定义添加单独的逻辑（如果适用），上述逻辑也可以在上述docs链接上获得。
// Choose authentication providers
List<AuthUI.IdpConfig> providers = Arrays.asList(
new AuthUI.IdpConfig.EmailBuilder().build(),
new AuthUI.IdpConfig.PhoneBuilder().build(),
new AuthUI.IdpConfig.GoogleBuilder().build(),
new AuthUI.IdpConfig.FacebookBuilder().build(),
new AuthUI.IdpConfig.TwitterBuilder().build());
// Create and launch sign-in intent
startActivityForResult(
AuthUI.getInstance()
.createSignInIntentBuilder()
.setAvailableProviders(providers)
.build(),
RC_SIGN_IN);