當我點擊“注冊”按鈕時，我的應用程序停止並退出

Question

enter code hereE/AndroidRuntime: FATAL EXCEPTION: main
Process: jdp.term5.babysittr, PID: 12904
java.lang.RuntimeException: Unable to start activity ComponentInfo{jdp.term5.babysittr/jdp.term5.babysittr.Register}: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process jdp.term5.babysittr. Make sure to call FirebaseApp.initializeApp(Context) first.
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
    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$H.handleMessage(ActivityThread.java:1808)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6669)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$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 jdp.term5.babysittr. Make sure to call FirebaseApp.initializeApp(Context) first.
    at com.google.firebase.FirebaseApp.getInstance(SourceFile:218)
    at com.google.firebase.auth.FirebaseAuth.getInstance(Unknown Source:1)
    at jdp.term5.babysittr.utility.firebasemethods.<init>(firebasemethods.java:31)
    at jdp.term5.babysittr.Register.onCreate(Register.java:51)
    at android.app.Activity.performCreate(Activity.java:7136)
    at android.app.Activity.performCreate(Activity.java:7127)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) 
    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$H.handleMessage(ActivityThread.java:1808) 
    at android.os.Handler.dispatchMessage(Handler.java:106) 
    at android.os.Looper.loop(Looper.java:193) 
    at android.app.ActivityThread.main(ActivityThread.java:6669) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) 

I / Process：正在發送信號。 PID：12904 SIG：9

我創建並注冊了頁面，其中包含電子郵件，用戶名和密碼，並將其加載到我的Firebase數據庫中。 但我似乎遇到了麻煩。

public class Register extends AppCompatActivity {

    private static final String TAG = "Register";

    private Context mContext;
    private String email, username, password;
    private EditText mEmail, mPassword, mUsername;
    private TextView loadingPleaseWait;
    private Button btnRegister;
    private ProgressBar mProgressBar;

    // firebase
    private FirebaseAuth mAuth;
    private FirebaseAuth.AuthStateListener mAuthListener;
    private firebasemethods Firebasemethods;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        Firebasemethods = new firebasemethods(mContext);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);
        mContext = Register.this;

        Log.d(TAG, "onCreate: started.");

        initWidgets();
        setupFirebaseAuth();
        init();
    }

    private void init() {
        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                email = mEmail.getText().toString();
                username = mUsername.getText().toString();
                password = mPassword.getText().toString();

                if (checkInputs(email, username, password)) {
                    mProgressBar.setVisibility(View.VISIBLE);
                    loadingPleaseWait.setVisibility(View.VISIBLE);

                    Firebasemethods.registerNewEmail(email, password, username);
                    profileNav();
                }
            }
        });
    }

    private boolean checkInputs(String email, String username, String password) {
        Log.d(TAG, "checkInputs: checking inputs for null values.");
        if (email.equals("") || username.equals("") || password.equals("")) {
            Toast.makeText(mContext, "All fields must be filled out.", Toast.LENGTH_SHORT).show();
            return false;
        }
        return true;
    }

    /**
     * Initialize the activity widgets
     */
    private void initWidgets() {
        Log.d(TAG, "initWidgets: Initializing Widgets.");
        mEmail = (EditText) findViewById(R.id.sign_in_email);
        mUsername = (EditText) findViewById(R.id.register_username);
        btnRegister = (Button) findViewById(R.id.register_button);
        // mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
        // loadingPleaseWait = (TextView) findViewById(R.id.loadingPleaseWait);
        mPassword = (EditText) findViewById(R.id.register_password);
        mContext = Register.this;
        mProgressBar.setVisibility(View.GONE);
        loadingPleaseWait.setVisibility(View.GONE);

    }

    private boolean isStringNull(String string) {
        Log.d(TAG, "isStringNull: checking string if null.");

        if (string.equals("")) {
            return true;
        } else {
            return false;
        }
    }

    private void setupFirebaseAuth() {
        Log.d(TAG, "setupFirebaseAuth: setting up firebase auth.");

        mAuth = FirebaseAuth.getInstance();

        mAuthListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                FirebaseUser user = firebaseAuth.getCurrentUser();

                if (user != null) {
                    // User is signed in
                    Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid());
                } else {
                    // User is signed out
                    Log.d(TAG, "onAuthStateChanged:signed_out");
                }
                // ...
            }
        };
    }

    @Override
    public void onStart() {
        super.onStart();
        mAuth.addAuthStateListener(mAuthListener);
    }

    @Override
    public void onStop() {
        super.onStop();
        if (mAuthListener != null) {
            mAuth.removeAuthStateListener(mAuthListener);
        }

    }

    private void profileNav() {

        Intent profileNavIntent = new Intent(Register.this, profile.class);
        startActivity(profileNavIntent);
        finish();
    }
}

我不明白未初始化的Firebase是什么意思

我試過了

super.onCreate();
//        FirebaseApp.initializeApp(this);

但是我不知道它會去哪里，我也不知道它是否能解決我的難題

Answer 1

FirebaseApp.initializeApp(this)應該進入擴展Application類。 例如：

public class ThisIsMyApp extends Application {
    @Override
    public void onCreate(){
        super.onCreate();
        FirebaseApp.initializeApp(this);
    }
}

如果它仍然無法在Google上正常運行，似乎是一個基本問題:)在此處查看更多解決方案： 默認FirebaseApp未初始化