Question

我创建了一个允许用户登录的应用程序，但每次尝试运行时，我的应用程序都会不断崩溃。

的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（用户登录成功的XML）

<?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（登录页面）

<?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 - ＆gt;类：AccountActivity（用户成功登录时的页面）

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 - ＆gt;类：FireApp（我认为是Firebase设置）

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 - ＆gt;类：主要活动（带帐户的后端日志记录）

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();
                    }
                }
            });
        }



    }
}

运行时出现错误消息：

 --------- 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.

错误的屏幕截图：

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

应用的方案：

创建帐户firebase Google（手动）
打开应用 - ＆gt;看到登录页面
使用Firebase帐户详细信息登录
转到AccountActivity页面

注意：我是AndroidStudio的业余/初学者。

Answer 1

错误非常明显。

您错过了在您的清单上添加AccounActivity ...

<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

在AccountActivity

中添加AndroidManifest.xml

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

Answer 3

始终仔细阅读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

我感谢大家给我解决方案。但是（如果有可能）你们知道为什么我的应用程序首先运行AccountActivity而不是我的Mainactivity吗？（它应该首先运行mainactivity？）

Answer 5

将清单文件中的.AccountActivity添加为

 <activity
    android:name=".AccountActivity">

   </activity>

Android Studio：代码已完成，但每次尝试运行时应用都会崩溃

5 个答案: