E/AndroidRuntime: FATAL EXCEPTION: main PID: 5112

Question

Hy

I am new to Android / Java is I am facing a BMO problem I code it but it does not work

an idea ??

thank you

<string name="onCreate_Go">onCreate Go</string>

            <TextView
            android:id="@+id/scrollTxt"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="18sp" />

import android.widget.TextView;

private final TextView txt = (TextView) this.findViewById(R.id.scrollTxt);

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

    txt.setText(R.string.onCreate_Go);
}

5112-5112/? E/AndroidRuntime: FATAL EXCEPTION: main Process: com.gmail.test1, PID: 5112 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.gmail.test1/com.gmail.test1.MainActivity}: java.lang.NullPointerException at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) at android.app.ActivityThread.access$800(ActivityThread.java:135) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5017) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.NullPointerException at android.support.v7.app.AppCompatDelegateImplBase.(AppCompatDelegateImplBase.java:117) at android.support.v7.app.AppCompatDelegateImplV9.(AppCompatDelegateImplV9.java:149) at android.support.v7.app.AppCompatDelegateImplV11.(AppCompatDelegateImplV11.java:29) at android.support.v7.app.AppCompatDelegateImplV14.(AppCompatDelegateImplV14.java:54) at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:202) at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:183) at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:519) at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:190) at com.gmail.test1.MainActivity.(MainActivity.java:13) at java.lang.Class.newInstanceImpl(Native Method) at java.lang.Class.newInstance(Class.java:1208) at android.app.Instrumentation.newActivity(Instrumentation.java:1061) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2112) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) at android.app.ActivityThread.access$800(ActivityThread.java:135) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5017) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) at dalvik.system.NativeStart.main(Native Method) 02-16 16:41:21.634 5112-5112/? I/Process: Sending signal. PID: 5112 SIG: 9

Trying to initialize the txt variable before the onCreate method will have null value cause you didnt setContentView yet. move it to the method onCreate — Marcos Vasconcelos, Feb 16 '18 at 17:56

score 0 · Answer 1 · answered Feb 16 '18 at 17:44

0

Please add your Activity in your AndroidManifest.xml. like below code:

<activity android:name=".activities.MainActivity"/>

Also put the findViewById() after setContentView() so it can actually return something other than null.

answered Feb 16 '18 at 17:44

Ali

3,346
4
21
56

score 0 · Answer 2 · answered Feb 16 '18 at 18:19

0

You can't initialize the textView before call "setContentView" method. I recommend you create a "init" method where initialize all layout's elements and call it after "setContentView"

answered Feb 16 '18 at 18:19

JaFer

213
2
10

E/AndroidRuntime: FATAL EXCEPTION: main PID: 5112

2 Answers2