我正在尝试使用Firebase对用户进行身份验证。我尝试使用Firebase quick start sample，只是将其更改为我已经创建的内容，但我不断出错。我已经看到了一些关于SO的示例和问题解决方案，它们帮助我解决了几个问题，但我仍然陷于困境。我得到的最新错误是：
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
W/System: ClassLoader referenced unknown path: /data/app/com.example.myproject-2/lib/arm
V/FA: Registered activity lifecycle callback
W/DynamiteModule: Local module descriptor class for com.google.firebase.auth not found.
I/FirebaseInitProvider: FirebaseApp initialization successful
W/DynamiteModule: Local module descriptor class for com.google.firebase.auth not found.
W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter androidx.vectordrawable.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
I/FirebaseAuth: [FirebaseAuth:] Preparing to create service connection to gms implementation
I/art: Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>
Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>
V/FA: Collection enabled
App package, google app id: com.example.myproject, 1:1068609878538:android:9b5be5dc4e43735d9f7df3
I/FA: App measurement is starting up, version: 18202
To enable debug logging run: adb shell setprop log.tag.FA VERBOSE
To enable faster debug mode event logging run:
adb shell setprop debug.firebase.analytics.app com.example.myproject
D/FA: Debug-level message logging enabled
V/BoostFramework: mAcquireFunc method = public int com.qualcomm.qti.Performance.perfLockAcquire(int,int[])
mReleaseFunc method = public int com.qualcomm.qti.Performance.perfLockRelease()
mAcquireTouchFunc method = public int com.qualcomm.qti.Performance.perfLockAcquireTouch(android.view.MotionEvent,android.util.DisplayMetrics,int,int[])
mIOPStart method = public int com.qualcomm.qti.Performance.perfIOPrefetchStart(int,java.lang.String)
mIOPStop method = public int com.qualcomm.qti.Performance.perfIOPrefetchStop()
V/BoostFramework: BoostFramework() : mPerf = com.qualcomm.qti.Performance@4a7b963
BoostFramework() : mPerf = com.qualcomm.qti.Performance@b784960
V/FA: Connecting to remote service
V/BoostFramework: BoostFramework() : mPerf = com.qualcomm.qti.Performance@98e1aea
D/MainActivity: onCreate: starting.
D/MainActivity: setupBottomNavigationView: setting up bottom navigation view
D/BottomNavigationViewHel: setupBottomNavigationView: Setting up bottom navigation view.
D/MainActivity: onStart: Starting MainActivity onStart method.
updateUI: checking if user is logged in.
D/MainActivity: onStart:signed_out.
V/FA: Activity resumed, time: 6079852
I/FA: Tag Manager is not found and thus will not be used
D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
D/FA: Logging event (FE): screen_view(_vs), Bundle[{ga_event_origin(_o)=auto, ga_screen_class(_sc)=MainActivity, ga_screen_id(_si)=-2493293364558908427}]
V/FA: Connection attempt already in progress
Connection attempt already in progress
Screen exposed for less than 1000 ms. Event not sent. time: 77
V/FA: Connection attempt already in progress
Activity paused, time: 6079882
D/EmailPassword: onCreate: started.
V/FA: onActivityCreated
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myproject, PID: 23204
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myproject/com.example.myproject.Login.LoginActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
这是我的代码：
public class LoginActivity extends Activity implements View.OnClickListener {
private static final String TAG = "EmailPassword";
private TextView mStatusTextView;
private TextView mDetailTextView;
private EditText mEmailField;
private EditText mPasswordField;
private FirebaseAuth mAuth;
@Override
public void onCreate(Bundle savedInstanceState) {
Log.d(TAG, "onCreate: started.");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
// Views
mEmailField = findViewById(R.id.input_email);
mPasswordField = findViewById(R.id.input_password);
// Buttons
findViewById(R.id.btn_login).setOnClickListener((View.OnClickListener) this);
findViewById(R.id.btn_register).setOnClickListener((View.OnClickListener) this);
// Initialize Firebase Auth
mAuth = FirebaseAuth.getInstance();
signOut();
}
@Override
public void onStart() {
Log.d(TAG, "onStart: started.");
super.onStart();
// Check if user is signed in (non-null) and update UI accordingly.
FirebaseUser currentUser = mAuth.getCurrentUser();
updateUI(currentUser);
}
private void createAccount(String email, String password) {
Log.d(TAG, "createAccount:" + email);
if (!validateForm()) {
return;
}
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Sign in success, update UI with the signed-in user's information
Log.d(TAG, "createUserWithEmail:success");
FirebaseUser user = mAuth.getCurrentUser();
updateUI(user);
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "createUserWithEmail:failure", task.getException());
Toast.makeText(LoginActivity.this, "Authentication failed.",
Toast.LENGTH_SHORT).show();
updateUI(null);
}
}
});
}
private void signIn(String email, String password) {
Log.d(TAG, "signIn:" + email);
if (!validateForm()) {
return;
}
mAuth.signInWithEmailAndPassword(email, password)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Sign in success, update UI with the signed-in user's information
Log.d(TAG, "signInWithEmail:success");
FirebaseUser user = mAuth.getCurrentUser();
updateUI(user);
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "signInWithEmail:failure", task.getException());
Toast.makeText(LoginActivity.this, "Authentication failed.",
Toast.LENGTH_SHORT).show();
updateUI(null);
}
if (!task.isSuccessful()) {
mStatusTextView.setText(R.string.auth_failed);
}
}
});
}
private void signOut() {
Log.d(TAG, "signOut: started.");
mAuth.signOut();
updateUI(null);
}
private boolean validateForm() {
Log.d(TAG, "validateForm: started.");
boolean valid = true;
String email = mEmailField.getText().toString();
if (TextUtils.isEmpty(email)) {
mEmailField.setError("Required.");
valid = false;
} else {
mEmailField.setError(null);
}
String password = mPasswordField.getText().toString();
if (TextUtils.isEmpty(password)) {
mPasswordField.setError("Required.");
valid = false;
} else {
mPasswordField.setError(null);
}
return valid;
}
private void updateUI(FirebaseUser user) {
Log.d(TAG, "updateUI: started.");
if (user != null) {
mStatusTextView.setText(getString(R.string.emailpassword_status_fmt, user.getEmail(), user.isEmailVerified()));
mDetailTextView.setText(getString(R.string.firebase_status_fmt, user.getUid()));
} else {
findViewById(R.id.btn_login).setVisibility(View.VISIBLE);
findViewById(R.id.pleaseWait).setVisibility(View.GONE);
findViewById(R.id.progressBar).setVisibility(View.GONE);
}
}
@Override
public void onClick(View view) {
Log.d(TAG, "onClick: started.");
findViewById(R.id.btn_login).setOnClickListener((View.OnClickListener) this);
findViewById(R.id.btn_register).setOnClickListener((View.OnClickListener) this);
int i = view.getId();
if (i == R.id.btn_register) {
createAccount(mEmailField.getText().toString(), mPasswordField.getText().toString());
} else if (i == R.id.btn_login) {
signIn(mEmailField.getText().toString(), mPasswordField.getText().toString());
}
}
}
答案 0 :(得分：1)
1。）确保调用findViewById()时使用的ID实际上存在。
2。）声明一个合适的变量来存储视图，我假设您正在使用Button，所以：
Button loginBtn;
public void onCreate(Bundle savedInstanceState) {
.......
loginBtn = findViewById(R.id.btn_login);
.......
}
3。）现在，您可以实现OnClickListener或简单地将其附加为：
loginBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//do your stuff
}
});
或通过实现OnClickListener：
@Override
public void onClick(View view) {
Log.d(TAG, "onClick: started.");
//Remove the extra call to attach the listener
int i = view.getId();
if (i == R.id.btn_register) {
createAccount(mEmailField.getText().toString(), mPasswordField.getText().toString());
} else if (i == R.id.btn_login) {
signIn(mEmailField.getText().toString(), mPasswordField.getText().toString());
}
}
onClick()