java - 尽管没有显示错误，但按下按钮时应用程序崩溃

Question

我正在尝试构建一个具有四种不同 Activity 的应用程序。

在我的起始页上，有 4 个按钮。当您单击按钮时，您应该被定向到相应的 Activity 。

虽然我的代码没有语法错误，但当我点击一个按钮时，我的应用程序总是崩溃。

有人可以告诉我我的代码有什么问题吗？

我的主要 Activity

package com.group6.travlhoe;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.IdRes;
import android.support.annotation.NonNull;
import android.support.design.widget.BaseTransientBottomBar;
import android.support.design.widget.BottomNavigationView;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements 
View.OnClickListener {

Button btnTransport, btnUnterkunft, btnAllgemein, btnRechnung;

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

    btnTransport = (Button) findViewById(R.id.Transport);
    btnAllgemein = (Button) findViewById(R.id.Allgemein);
    btnUnterkunft = (Button) findViewById(R.id.Unterkunft);
    btnRechnung = (Button) findViewById(R.id.Rechnung);

    btnTransport.setOnClickListener(this);
    btnRechnung.setOnClickListener(this);
    btnAllgemein.setOnClickListener(this);
    btnUnterkunft.setOnClickListener(this);
}


@Override
public void onClick(View v) {
    if (v.getId() == R.id.Allgemein) {
        startActivity(new Intent(MainActivity.this, Allgemein.class));
    } else if (v.getId() == R.id.Transport) {
        startActivity(new Intent(MainActivity.this, Transport.class));
    } else if (v.getId() == R.id.Unterkunft) {
        startActivity(new Intent(MainActivity.this, Unterkunft.class));
    } else if (v.getId() == R.id.Rechnung) {
        startActivity(new Intent(MainActivity.this, Rechnung.class));
    }
    }
}

按钮应指向的类之一:

package com.group6.travlhoe;

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



public class Allgemein extends AppCompatActivity {

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_allgemein);
    }
}

我的错误日志文件:

06-22 17:33:17.073 1414-1600/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:17.073 1414-1600/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:17.073 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:17.074 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:17.074 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:22.111 1414-1599/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:22.111 1414-1599/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:22.111 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:22.120 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:22.120 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:26.330 1517-1530/? E/memtrack: Couldn't load memtrack module
06-22 17:33:27.159 1414-1499/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:27.159 1414-1499/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:27.159 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:27.165 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:27.166 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:32.203 1414-1499/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:32.203 1414-1499/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:32.203 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:32.211 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:32.211 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:37.259 1414-1599/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:37.259 1414-1599/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:37.260 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:37.265 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:37.265 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:42.359 1414-1414/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:42.360 1414-1414/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:42.360 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:42.366 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:42.368 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:47.604 1414-1599/? E/AudioFlinger: not enough memory for AudioTrack size=131296
06-22 17:33:47.606 1414-1599/? E/AudioFlinger: createRecordTrack_l() initCheck failed -12; no control block?
06-22 17:33:47.652 2269-10242/? E/AudioRecord: AudioFlinger could not create record track, status: -12
06-22 17:33:47.824 2269-10242/? E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check failed with status -12.
06-22 17:33:47.825 2269-10242/? E/android.media.AudioRecord: Error code -20 when initializing native AudioRecord object.
06-22 17:33:47.835 2269-10242/? E/ActivityThread: Failed to find provider info for com.google.android.apps.gsa.testing.ui.audio.recorded
06-22 17:33:48.125 1517-1530/? E/memtrack: Couldn't load memtrack module
06-22 17:33:48.760 1417-1573/? E/installd: Failed to delete /data/app/vmdl1116498233.tmp: No such file or directory
06-22 17:33:48.930 2154-4609/? E/NetworkScheduler.SR: Invalid parameter app
06-22 17:33:48.930 2154-4609/? E/NetworkScheduler.SR: Invalid package name : Perhaps you didn't include a PendingIntent in the extras?
06-22 17:33:49.162 2656-2656/? E/Finsky: [2] com.google.android.finsky.wear.bl.a(3): onConnectionFailed: ConnectionResult{statusCode=API_UNAVAILABLE, resolution=null, message=null}
06-22 17:33:49.272 2154-4609/? E/NetworkScheduler.SR: Invalid parameter app
06-22 17:33:49.272 2154-4609/? E/NetworkScheduler.SR: Invalid package name : Perhaps you didn't include a PendingIntent in the extras?
06-22 17:33:49.547 1342-1342/? E/hw-IPCThreadState: binder thread pool (1 threads) starved for 130 ms
06-22 17:33:49.752 2269-9548/? E/ContentStoreEUAS: Failed to commit the deferred actions
06-22 17:33:51.037 1352-1368/? E/SurfaceFlinger: ro.sf.lcd_density must be defined as a build property
06-22 17:33:51.525 2154-4609/? E/ctxmgr: [AppIntervalImpl]closeInterval: ongoing
06-22 17:33:51.545 2154-2383/? E/UidImportanceUtils: exception when invoking removeOnUidImportanceListener
                                                     java.lang.reflect.InvocationTargetException
                                                         at java.lang.reflect.Method.invoke(Native Method)
                                                         at alvy.a(:com.google.android.gms:1123)
                                                         at akva.a(:com.google.android.gms:44820)
                                                         at lsx.a(:com.google.android.gms:246)
                                                         at akuz.run(:com.google.android.gms:2812)
                                                         at android.os.Handler.handleCallback(Handler.java:769)
                                                         at android.os.Handler.dispatchMessage(Handler.java:98)
                                                         at alxb.dispatchMessage(:com.google.android.gms:3028)
                                                         at android.os.Looper.loop(Looper.java:164)
                                                         at android.os.HandlerThread.run(HandlerThread.java:65)
                                                      Caused by: java.lang.IllegalArgumentException: Listener not registered: alvz@2c93e02
                                                         at android.app.ActivityManager.removeOnUidImportanceListener(ActivityManager.java:3628)
                                                         at java.lang.reflect.Method.invoke(Native Method) 
                                                         at alvy.a(:com.google.android.gms:1123) 
                                                         at akva.a(:com.google.android.gms:44820) 
                                                         at lsx.a(:com.google.android.gms:246) 
                                                         at akuz.run(:com.google.android.gms:2812) 
                                                         at android.os.Handler.handleCallback(Handler.java:769) 
                                                         at android.os.Handler.dispatchMessage(Handler.java:98) 
                                                         at alxb.dispatchMessage(:com.google.android.gms:3028) 
                                                         at android.os.Looper.loop(Looper.java:164) 
                                                         at android.os.HandlerThread.run(HandlerThread.java:65) 
06-22 17:33:53.354 1517-1608/? E/TaskPersister: File error accessing recents directory (directory doesn't exist?).
06-22 17:34:00.005 1517-1530/? E/memtrack: Couldn't load memtrack module

Android list 文件:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.group6.travlhoe">

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

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 1

您缺少 list 中的 Activity 。当您创建 Activity 时，也必须将其添加到此处。

我建议阅读Android Application Fundamentals .

 <activity
        android:name=".MainActivity"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

<activity
    android:name=".Allgemein"
    android:launchMode="singleTop"/>

此外，在您为 Activity 提供的示例中，您没有覆盖 onCreate 方法。确保您的所有 Activity 都有此更改。

public class Allgemein extends AppCompatActivity {

    @Override //You are missing this.
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_allgemein);
    }
}