Android Studio：代码已完成，但是每次我尝试运行时应用崩溃

Question

I've made an app that allows user to login but everytime I try to run, my App is crashing constantly.

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.mertino11.ourapplication">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:name=".FireApp"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true">
        <activity
            android:name=".MainActivity"
            android:theme="@style/AppTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
    </application>
    </manifest>

activity_account.xml (XML for user logged in succesfully)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_account"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.mertino11.ourapplication.AccountActivity">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="textPersonName"
        android:text="Account Page"
        android:ems="10"
        android:id="@+id/editText"
        android:textSize="22sp"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:textStyle="normal|bold"
        android:textAlignment="center" />
</RelativeLayout>

activity_main.xml (login page)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:baselineAligned="false">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textEmailAddress"
        android:ems="10"
        android:id="@+id/emailField"
        android:hint="Email"
        android:paddingTop="20dp" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textPassword"
        android:ems="10"
        android:id="@+id/passwordField"
        android:hint="Password"
        android:fontFamily="sans-serif"
        android:paddingTop="20dp" />

    <Button
        android:text="Login"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/loginBtn"
        android:paddingTop="20dp" />
</LinearLayout>

Java --> Class: AccountActivity (Page when the user logged in successfully)

package com.example.mertino11.ourapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class AccountActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_account);
    }
}

Java --> Class: FireApp (Firebase settings I think)

package com.example.mertino11.ourapplication;

import android.app.Application;

import com.firebase.client.Firebase;

/**
 * Created by Mertino11 on 10-Dec-16.
 */

public class FireApp extends Application {

    @Override
    public void  onCreate() {
        super.onCreate();

        Firebase.setAndroidContext(this);
    }
}

Java --> Class: Main Activity (Back-end logging with account)

package com.example.mertino11.ourapplication;


import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

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;

public class MainActivity extends AppCompatActivity {

    private EditText mEmailField;
    private EditText mPasswordField;

    private Button mLoginBtn;

    private FirebaseAuth mAuth;

    private FirebaseAuth.AuthStateListener mAuthListener;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mAuth = FirebaseAuth.getInstance();

        mEmailField = (EditText) findViewById(R.id.emailField);
        mPasswordField = (EditText) findViewById(R.id.passwordField);

        mLoginBtn = (Button) findViewById(R.id.loginBtn);

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

                if(firebaseAuth.getCurrentUser() != null) {

                    startActivity(new Intent(MainActivity.this, AccountActivity.class));

                }
            }
        };

        mLoginBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                startSignIn();

            }
        });
    }

    @Override
    protected void onStart() {
        super.onStart();

        mAuth.addAuthStateListener(mAuthListener);
    }

    private void startSignIn() {

        String email = mEmailField.getText().toString();
        String password = mPasswordField.getText().toString();

        if(TextUtils.isEmpty(email) || TextUtils.isEmpty(password)) {

            Toast.makeText(MainActivity.this, "Fields are empty!", Toast.LENGTH_LONG).show();

        } else {
            mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {

                    if(!task.isSuccessful()){

                        Toast.makeText(MainActivity.this, "Sign In Problem!", Toast.LENGTH_LONG).show();
                    }
                }
            });
        }



    }
}

Error Message at Run:

 --------- beginning of crash
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.mertino11.ourapplication, PID: 3060
                  android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.mertino11.ourapplication/com.example.mertino11.ourapplication.AccountActivity}; have you declared this activity in your AndroidManifest.xml?
                      at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1805)
                      at android.app.Instrumentation.execStartActivity(Instrumentation.java:1523)
                      at android.app.Activity.startActivityForResult(Activity.java:4224)
                      at android.support.v4.app.BaseFragmentActivityJB.startActivityForResult(BaseFragmentActivityJB.java:48)
                      at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:75)
                      at android.app.Activity.startActivityForResult(Activity.java:4183)
                      at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:856)
                      at android.app.Activity.startActivity(Activity.java:4507)
                      at android.app.Activity.startActivity(Activity.java:4475)
                      at com.example.mertino11.ourapplication.MainActivity$1.onAuthStateChanged(MainActivity.java:48)
                      at com.google.firebase.auth.FirebaseAuth$1.run(Unknown Source)
                      at android.os.Handler.handleCallback(Handler.java:751)
                      at android.os.Handler.dispatchMessage(Handler.java:95)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6077)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Application terminated.

Screenshot of the error:

http://i66.tinypic.com/51btrp.png

The scenario of the app:

• Create account firebase Google (manually)
• Opens app --> Sees login page
• Logs in with accountdetails of Firebase
• Goes to AccountActivity page

Note: I am a amateur/beginner with AndroidStudio.

Answer 1

The error is pretty self-explanatory.

You have missed adding the AccounActivity on your manifest...

<application
    android:name=".FireApp"
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true">
    <activity
        android:name=".MainActivity"
        android:theme="@style/AppTheme">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
    <activity
        android:name=".AccountActivity"
        android:theme="@style/AppTheme" />
</application>

Answer 2

Add AccountActivity in your AndroidManifest.xml

<activity
        android:name=".AccountActivity">
        <intent-filter>
            ...
        </intent-filter>
</activity>

Answer 3

务必仔细阅读logcat：

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.mertino11.ourapplication/com.example.mertino11.ourapplication.AccountActivity}; have you declared this activity in your AndroidManifest.xml?

Answer 4

I thank you all for giving me the solution. However (If it is possible) do you guys know why my App is running AccountActivity first instead of my Mainactivity? (it should run the mainactivity first)?

Answer 5

add .AccountActivity in manifest file as

 <activity
    android:name=".AccountActivity">

   </activity>