Unfortunately my app has stopped in Android Emulator [duplicate]

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This question already has answers here:

Unfortunately MyApp has stopped. How can I solve this? (23 answers)

Closed 8 years ago.

I've been looking for an answer for hours now, but my calculator wont work at all :(

I appreciate if you could help me. I've posted the manifest code below. Inform me if you need to see the MainActivity.java or anything else :)

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.elof_calc_2000_dragonslayerxx"
android:versionCode="1"
android:versionName="1.0" >

 <uses-sdk
    android:minSdkVersion="15"
    android:targetSdkVersion="17" />

 <application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
     android:name="com.example.elof_calc_2000_dragonslayerxx.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>

The errors shown on Logcat

03-16 18:09:59.890: E/AndroidRuntime(895): FATAL EXCEPTION: main
03-16 18:09:59.890: E/AndroidRuntime(895): Process: com.example.elof_calc_2000_dragonslayerxx,     PID: 895
03-16 18:09:59.890: E/AndroidRuntime(895): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.elof_calc_2000_dragonslayerxx/com.example.elof_calc_2000_dragonslayerxx.MainActivity}: java.lang.NullPointerException
03-16 18:09:59.890: E/AndroidRuntime(895):  at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.access$800(ActivityThread.java:135)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.os.Handler.dispatchMessage(Handler.java:102)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.os.Looper.loop(Looper.java:136)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.main(ActivityThread.java:5017)
03-16 18:09:59.890: E/AndroidRuntime(895):  at java.lang.reflect.Method.invokeNative(Native Method)
03-16 18:09:59.890: E/AndroidRuntime(895):  at java.lang.reflect.Method.invoke(Method.java:515)
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-16 18:09:59.890: E/AndroidRuntime(895):  at dalvik.system.NativeStart.main(Native Method)
03-16 18:09:59.890: E/AndroidRuntime(895): Caused by: java.lang.NullPointerException
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onClickListeners(MainActivity.java:49)
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onCreate(MainActivity.java:22)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.Activity.performCreate(Activity.java:5231)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-16 18:09:59.890: E/AndroidRuntime(895):  ... 11 more
03-16 18:16:23.316: E/AndroidRuntime(1100): FATAL EXCEPTION: main
03-16 18:16:23.316: E/AndroidRuntime(1100): Process: com.example.elof_calc_2000_dragonslayerxx, PID: 1100
03-16 18:16:23.316: E/AndroidRuntime(1100): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.elof_calc_2000_dragonslayerxx/com.example.elof_calc_2000_dragonslayerxx.MainActivity}: java.lang.NullPointerException
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.os.Looper.loop(Looper.java:136)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.main(ActivityThread.java:5017)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at java.lang.reflect.Method.invokeNative(Native Method)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at java.lang.reflect.Method.invoke(Method.java:515)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at dalvik.system.NativeStart.main(Native Method)
03-16 18:16:23.316: E/AndroidRuntime(1100): Caused by: java.lang.NullPointerException
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onClickListeners(MainActivity.java:49)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onCreate(MainActivity.java:22)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.Activity.performCreate(Activity.java:5231)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-16 18:16:23.316: E/AndroidRuntime(1100):     ... 11 more

Answer 1

Here are your key lines

03-16 18:16:23.316: E/AndroidRuntime(1100): Caused by: java.lang.NullPointerException
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onClickListeners(MainActivity.java:49)

You have a NullPointerException on line 49 of your MainActivity. You can post that for further help. Whatever code is there ensure that it is initialized (and thus not null) before you call it.