nullpointerexception at Action bar setDisplayShowHomeEnabled () in Android

Question

I create custom action bar I really don't know where is my mistake.I have some problems while creating Custom action bar.

And showing the null pointer exception at the line = mActionBar.setDisplayShowHomeEnabled(false);

Here is my error log

07-29 16:19:20.180  32714-32714/com.example.tazeen.classnkk E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.tazeen.classnkk/com.example.tazeen.classnkk.AllPosts_Page}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
            at android.app.ActivityThread.access$600(ActivityThread.java:123)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4424)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.example.tazeen.classnkk.AllPosts_Page.CustomActionBar(AllPosts_Page.java:37)
            at com.example.tazeen.classnkk.AllPosts_Page.onCreate(AllPosts_Page.java:28)
            at android.app.Activity.performCreate(Activity.java:4466)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
            at android.app.ActivityThread.access$600(ActivityThread.java:123)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4424)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
            at dalvik.system.NativeStart.main(Native Method)

I have try last 5 to 7 hours , but can not find any proper solution.Please help me.Thanks.

Here is my Activity code

public class AllPosts_Page extends Activity
{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.all_post);
        CustomActionBar();
    }
public void CustomActionBar()
    {
        android.app.ActionBar mActionBar = getActionBar();
        mActionBar.setDisplayShowHomeEnabled(false);
        mActionBar.setDisplayShowTitleEnabled(false);

        LayoutInflater mInflater = LayoutInflater.from(this);

        View mCustomView = mInflater.inflate(R.layout.custom_action_bar, null);
        TextView mTitleTextView = (TextView) mCustomView.findViewById(R.id.txtTitle);
        mTitleTextView.setText("All Post");


        ImageView imageButton = (ImageView) mCustomView
                .findViewById(R.id.imgLeftMenu);
        imageButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                Toast.makeText(getApplicationContext(), "Refresh Clicked!",
                        Toast.LENGTH_LONG).show();
            }
        });


        mActionBar.setCustomView(mCustomView);
        mActionBar.setDisplayShowCustomEnabled(true);
    }

menifest file

 <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar">
        <activity
            android:name=".Splash_Screen"
            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=".Login_Screen" />
        <activity
            android:name=".AllPosts_Page">
        </activity>
        <activity
            android:name=".Filter_Page"
            android:label="@string/title_activity_filter__page"
            android:theme="@style/ListFont">
        </activity>
    </application>

</manifest>

style.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="android:height">5dp</item>
</style>
</resources>

null pointer exception at the line = mActionBar.setDisplayShowHomeEnabled(false); — Androiddv, Jul 29 '15 at 11:07
your `mActionBar` is null. `getActionBar()` is the correct place to look for issue. — Ambrish, Jul 29 '15 at 11:07
http://stackoverflow.com/questions/6867076/getactionbar-returns-null — moffeltje, Jul 29 '15 at 11:08

snachmsm · Accepted Answer · 2015-07-29T13:04:10.743

2

you are using Theme.AppCompat.Light.DarkActionBar so you should get your ActionBar by getSupportActionBar() method, not getActionBar()

if your extended Activity is from Android system then style is incorrect (AppCompat) and Activity gets some default styling without ActionBar, so getActionBar() return null

else if you want to use this AppCompat style it is applicable for AppCompatActivity (and then you use should getSupportActionBar())

edited Jul 29 '15 at 13:04

answered Jul 29 '15 at 11:11

snachmsm

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I dont understand what you saying ? Means where i have to change in my coding . Can you explain please. – Androiddv Jul 29 '15 at 11:22
but when i use this ActionBar mAct = getSupportActionBar(); InCompatible type required android.app.ActionBar and found: android.support.v7.app.ActionBar . And when import android.app.ActionBar this then getSupportActionBar() does not get support. – Androiddv Jul 29 '15 at 11:48
Thanks it solves my problem. Thanks a lot. But my custom action bar is not set proper , it shows left and right side default action bar space . – Androiddv Jul 29 '15 at 12:08

nullpointerexception at Action bar setDisplayShowHomeEnabled () in Android

1 Answers1