App stürzt ab, wie kann ich das beheben?

  • App stürzt ab, wie kann ich das beheben?

    Beim Starten eines neuen Intents stürzt meine App ab.
    Es folgen die Einträge des Logcat und die gestartete Datei(.java + .xml in .txt-Form im Anhang, da zu lang...)...
    (Ich bin erst seit ca. 1 Woche dabei, diese Sprache zu erlernen...)
    Es kann übrigens nur an dieser Datei liegen, da ich seit dem letzten Testen, bei dem noch alles funktionierte, die anderen Dateien nicht angefasst habe...

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    08-11 22:31:50.278 1487-1520/com.androidstudio.secondtest I/OpenGLRenderer: Initialized EGL, version 1.4
    08-11 22:31:50.278 1487-1520/com.androidstudio.secondtest D/OpenGLRenderer: Swap behavior 1
    08-11 22:31:50.431 1487-1487/com.androidstudio.secondtest W/art: Before Android 4.1, method int android.support.v7.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
    08-11 22:31:51.018 1487-1487/com.androidstudio.secondtest I/Choreographer: Skipped 34 frames! The application may be doing too much work on its main thread.
    08-11 22:31:53.972 1487-1487/com.androidstudio.secondtest D/AndroidRuntime: Shutting down VM
    08-11 22:31:53.974 1487-1487/com.androidstudio.secondtest E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.androidstudio.secondtest, PID: 1487
    java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.androidstudio.secondtest/com.androidstudio.secondtest.Activity_Multi}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2567)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6119)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
    at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:120)
    at android.support.v7.app.AppCompatDelegateImplV9.<init>(AppCompatDelegateImplV9.java:155)
    at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:31)
    at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:55)
    at android.support.v7.app.AppCompatDelegateImplV23.<init>(AppCompatDelegateImplV23.java:33)
    at android.support.v7.app.AppCompatDelegateImplN.<init>(AppCompatDelegateImplN.java:33)
    at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:201)
    at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:185)
    at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:519)
    at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:190)
    at com.androidstudio.secondtest.Activity_Multi.<init>(Activity_Multi.java:40)
    at java.lang.Class.newInstance(Native Method)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1078)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2557)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6119)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
    Dateien