CODEWITHSUNDEEP
javaandroidnullpointerexception
Androiddv
Androiddv

Reputation: 47

nullpointerexception at Action bar setDisplayShowHomeEnabled () in Android

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>

Upvotes: 0

Views: 1718

Answers (1)

snachmsm
snachmsm

Reputation: 19243

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())

Upvotes: 2

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