不幸的是，应用程序已停止在模拟器中工作
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【中文标题】不幸的是，应用程序已停止在模拟器中工作【英文标题】：Unfortunately App has stopped working In Emulator 【发布时间】：2014-11-03 10:56:19 【问题描述】：我在模拟器中运行我的应用时遇到此错误：
不幸的是应用程序已停止
My App 是一款功能简单的音乐播放器应用。
所有其他应用都在同一个模拟器中完美运行。只有这个应用程序不工作。
查看日志后，我也看到了这个错误：
09-10 16:01:28.460: E/androidRuntime(1200): Caused by: java.lang.InstantiationException: can't instantiate class com.example.musicplayer.MainActivity
MainActivity.java的代码：
package com.example.musicplayer;
import com.example.musicplayer.R;
//import com.example.musicplayer.secondscreen;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.TextView;
public abstract class MainActivity extends Activity implements OnClickListener
SeekBar seek_bar;
Button play_button, pause_button;
MediaPlayer player;
TextView text_shown;
Handler seekHandler = new Handler();
ImageButton button;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getInit();
seekUpdation();
addListenerOnButton();
//Function for Button press to change the screen
public void addListenerOnButton()
final Context context = this;
button = (ImageButton) findViewById(R.id.btnForward);
button.setOnClickListener(new OnClickListener()
@Override
public void onClick(View arg0)
Intent intent = new Intent(context, SecondScreen.class);
startActivity(intent);
);
//function for play/pause Audio
public void getInit()
seek_bar = (SeekBar) findViewById(R.id.seek_bar);
play_button = (Button) findViewById(R.id.btnPlay);
pause_button = (Button) findViewById(R.id.btnPause);
//text_shown = (TextView) findViewById(R.id.text_shown);
play_button.setOnClickListener(this);
pause_button.setOnClickListener(this);
player = MediaPlayer.create(this, R.raw.fat); //ye wo Audio file hai jo chalarae
seek_bar.setMax(player.getDuration());
Runnable run = new Runnable()
@Override
public void run()
seekUpdation();
;
// function for update seekbar
public void seekUpdation()
seek_bar.setProgress(player.getCurrentPosition());
seekHandler.postDelayed(run, 1000);
activity_main.xml的代码：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_
android:layout_ >
<!-- Player Header -->
<LinearLayout
android:id="@+id/player_header_bg"
android:layout_
android:layout_
android:layout_alignParentTop="true"
android:paddingLeft="5dp"
android:paddingRight="5dp">
<!-- Audio Title -->
<TextView
android:id="@+id/audioTitle"
android:layout_
android:layout_
android:layout_weight="1"
android:textColor="#04b3d2"
android:textSize="16dp"
android:paddingLeft="10dp"
android:textStyle="bold"
android:text="1"
android:layout_marginTop="10dp"/>
<!-- Playlist button -->
<ImageButton
android:id="@+id/btnPlaylist"
android:layout_
android:layout_
android:src="@drawable/btn_playlist"
android:background="@null"/>
</LinearLayout>
<!-- Sabak Image -->
<LinearLayout
android:id="@+id/AudioThumbnail"
android:layout_
android:layout_
android:gravity="center"
android:paddingBottom="10dp"
android:paddingTop="10dp" >
<ImageView
android:layout_
android:layout_
android:src="@drawable/fatiha" />
</LinearLayout>
<!-- Player Footer -->
<LinearLayout
android:id="@+id/player_footer_bg"
android:layout_
android:layout_
android:layout_alignParentBottom="true"
android:gravity="center">
<!-- Player Buttons -->
<LinearLayout
android:layout_
android:layout_
android:orientation="horizontal"
android:gravity="center_vertical"
android:paddingLeft="10dp"
android:paddingRight="10dp">
<!-- Previous Button -->
<!-- Backward Button -->
<ImageButton
android:id="@+id/btnBackward"
android:src="@drawable/btn_backward"
android:layout_
android:layout_
android:background="@null"/>
<!-- Pause Button -->
<ImageButton
android:id="@+id/btnPause"
android:layout_
android:layout_
android:background="@null"
android:enabled="false"
android:gravity="center"
android:src="@drawable/btn_pause" />
<!-- Play Button -->
<ImageButton
android:id="@+id/btnPlay"
android:layout_
android:layout_
android:background="@null"
android:src="@drawable/btn_play"
android:gravity="center" />
<!-- Forward Button -->
<ImageButton
android:id="@+id/btnForward"
android:layout_
android:layout_
android:background="@null"
android:src="@drawable/btn_forward" />
</LinearLayout>
</LinearLayout>
<!-- SABAK Progress Bar/Seek bar -->
<SeekBar
android:id="@+id/seek_bar"
android:layout_
android:layout_
android:layout_marginRight="20dp"
android:layout_marginLeft="20dp"
android:layout_marginBottom="20dp"
android:layout_above="@id/player_footer_bg"
android:thumb="@drawable/seek_handler"
android:progressDrawable="@drawable/seekbar_progress"
android:paddingLeft="6dp"
android:paddingRight="6dp"/>
<LinearLayout
android:layout_
android:layout_
android:layout_above="@+id/audioProgressBar"
android:gravity="center" >
</LinearLayout>
</RelativeLayout>
Manifest.xml 的代码：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.musicplayer"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.musicplayer.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>
LogCat：
09-10 16:01:28.250: D/dalvikvm(1200): newInstance failed: p0 i0 [0 a1
09-10 16:01:28.250: D/AndroidRuntime(1200): Shutting down VM
09-10 16:01:28.260: W/dalvikvm(1200): threadid=1: thread exiting with uncaught exception (group=0xb3b0bb90)
09-10 16:01:28.460: E/AndroidRuntime(1200): FATAL EXCEPTION: main
09-10 16:01:28.460: E/AndroidRuntime(1200): Process: com.example.musicplayer, PID: 1200
09-10 16:01:28.460: E/AndroidRuntime(1200): java.lang.RuntimeException: Unable to instantiate activity ComponentInfocom.example.musicplayer/com.example.musicplayer.MainActivity: java.lang.InstantiationException: can't instantiate class com.example.musicplayer.MainActivity
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2102)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.ActivityThread.access$700(ActivityThread.java:135)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.os.Handler.dispatchMessage(Handler.java:102)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.os.Looper.loop(Looper.java:137)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.ActivityThread.main(ActivityThread.java:4998)
09-10 16:01:28.460: E/AndroidRuntime(1200): at java.lang.reflect.Method.invokeNative(Native Method)
09-10 16:01:28.460: E/AndroidRuntime(1200): at java.lang.reflect.Method.invoke(Method.java:515)
09-10 16:01:28.460: E/AndroidRuntime(1200): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
09-10 16:01:28.460: E/AndroidRuntime(1200): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
09-10 16:01:28.460: E/AndroidRuntime(1200): at dalvik.system.NativeStart.main(Native Method)
09-10 16:01:28.460: E/AndroidRuntime(1200): Caused by: java.lang.InstantiationException: can't instantiate class com.example.musicplayer.MainActivity
09-10 16:01:28.460: E/AndroidRuntime(1200): at java.lang.Class.newInstanceImpl(Native Method)
09-10 16:01:28.460: E/AndroidRuntime(1200): at java.lang.Class.newInstance(Class.java:1208)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
09-10 16:01:28.460: E/AndroidRuntime(1200): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2093)
09-10 16:01:28.460: E/AndroidRuntime(1200): ... 11 more
【问题讨论】：
请显示您的堆栈跟踪。我们需要知道异常是什么。 如果没有您得到的异常的堆栈跟踪，我们将无法帮助您。从 logcat 添加完整的堆栈跟踪。 （PS：如果错误是关于在清单中声明活动，请检查下面的答案） 请看一下我刚刚发布的 Logcat 消息。 【参考方案1】：java.lang.InstantiationException: can't instantiate class com.example.musicplayer.MainActivity
您的MainActivity 是abstract，并且无法实例化抽象类。从类声明中删除 abstract 关键字。
【讨论】：
【参考方案2】：您正在尝试启动未在 Manifest 文件中声明的 SecondScreen 活动。
<activity android:name="com.example.musicplayer.SecondScreen" />
有关如何在活动之间切换和在它们之间传递数据的更多详细信息，您可以按照本教程进行操作： http://www.android-ios-tutorials.com/117/how-to-switch-between-different-activities-in-android/
编辑 ：
活动MainActivity 不应该是抽象的；从声明中删除abstract：
public class MainActivity extends Activity ...
【讨论】：
是的，您是对的。感谢您的回答:) 我现在在我的清单文件中添加了这一行。但问题仍然存在......:(请看一下我刚刚在这里发布的 logCat @Liza : 查看我的编辑，abstract 关键字应该被删除，activity 不应该是抽象的以上是关于不幸的是，应用程序已停止在模拟器中工作的主要内容，如果未能解决你的问题，请参考以下文章
IBM Worklight - Android SDK - 模拟器部署问题 - 不幸的是，“应用程序”已停止