Issues on onCreateOptionsMenu for android.view.View android.view.View.findViewById(int) on a null object reference

Question

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.material.components, PID: 11563
                  java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
                      at com.material.components.activity.dashboard.Dashboard.onCreateOptionsMenu(Dashboard.java:251)

The problems at this line:-

ui_hot = menu_hotlist.findViewById(R.id.hotlist_hot);

What's happen? I tried to findViewById in menu but android could not ever find object reference. Anyone can help me? Thanks.

Full codes:

Dashboard.java:

@Override
public boolean onCreateOptionsMenu(final Menu menu) {

    MenuInflater menuInflater = getMenuInflater();
    menuInflater.inflate(R.menu.menu_dashboard, menu);
    final View menu_hotlist = menu.findItem(R.id.action_notification).getActionView();
    ui_hot = menu_hotlist.findViewById(R.id.hotlist_hot); //Problem location
    updateHotCount(hot_number);
    new MyMenuItemStuffListener(menu_hotlist, "Show hot message") {
        @Override
        public void onClick(View v) {

        }
    };
    return super.onCreateOptionsMenu(menu);
}

menu_dashboard.xml:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <item
        android:id="@+id/action_search"
        android:icon="@drawable/ic_search"
        android:orderInCategory="100"
        android:title="Search"
        app:showAsAction="always" />

    <item
        android:id="@+id/action_notification"
        android:actionLayout="@layout/action_bar_notifitcation_icon"
        app:showAsAction="always"
        android:icon="@drawable/ic_notifications"
        android:title="Notifications"
        />


    <item
        android:id="@+id/lessons_discuss_with_teacher"
        android:orderInCategory="100"
        android:title="Ask Teacher List"
        app:showAsAction="never" />
</menu>

action_bar_notification_icon.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:gravity="center"
    android:layout_gravity="center"
    android:clickable="true"
    style="@android:style/Widget.ActionButton">

    <ImageView
        android:id="@+id/hotlist_bell"
        app:srcCompat="@drawable/ic_notifications"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_margin="0dp"
        android:contentDescription="bell"
        />

    <TextView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/hotlist_hot"
        android:layout_width="wrap_content"
        android:minWidth="17sp"
        android:textSize="12sp"
        android:textColor="#ffffffff"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="@null"
        android:layout_alignTop="@id/hotlist_bell"
        android:layout_alignRight="@id/hotlist_bell"
        android:layout_marginRight="0dp"
        android:layout_marginTop="3dp"
        android:paddingBottom="1dp"
        android:paddingRight="4dp"
        android:paddingLeft="4dp"
        android:background="@drawable/rounded_square"/>
</RelativeLayout>

[https://stackoverflow.com/questions/18438890/menuitemcompat-getactionview-always-returns-null](https://stackoverflow.com/questions/18438890/menuitemcompat-getactionview-always-returns-null). — ADM, Feb 12 '18 at 07:05

IntelliJ Amiya · Accepted Answer · 2018-02-12T07:23:43.300

2

NullPointerException is thrown when an application attempts to use an object reference that has the null value.

Try with

MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu_dashboard, menu);   
    MenuItem menuITEM = menu.findItem(R.id.action_notification);
    View view         = menuITEM.getActionView();
    ui_hot            = view.findViewById(R.id.hotlist_hot);

FYI

You should call app:actionLayout

edited Feb 12 '18 at 07:23

answered Feb 12 '18 at 07:08

IntelliJ Amiya

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@Nere where you call `action_bar_notification_icon` layout? – IntelliJ Amiya Feb 12 '18 at 07:20
`android:id="@+id/action_notification" android:actionLayout="@layout/action_bar_notifitcation_icon"` – Nere Feb 12 '18 at 07:21
I called it in `menu_dashboard.xml` – Nere Feb 12 '18 at 07:22
@Nere call `app:actionLayout` – IntelliJ Amiya Feb 12 '18 at 07:23
So..what's the difference if I use `android:actionLayout`? – Nere Feb 12 '18 at 07:23
2

Read https://stackoverflow.com/questions/28045648/android-layout-when-to-use-app-vs-android – IntelliJ Amiya Feb 12 '18 at 07:26
1

Thanks! You really help me a lot. – Nere Feb 12 '18 at 07:27

score 0 · Answer 2 · edited Feb 04 '20 at 02:13

Use getSupportMenuInflater

@Override public boolean onCreateOptionsMenu(final Menu menu) {
    MenuInflater menuInflater = getSupportMenuInflater();
    menuInflater.inflate(R.menu.menu_actionbar, menu);
    final View menu_hotlist = menu.findItem(R.id.menu_hotlist).getActionView();
    ui_hot = (TextView) menu_hotlist.findViewById(R.id.hotlist_hot);
    updateHotCount(hot_number);
    new MyMenuItemStuffListener(menu_hotlist, "Show hot message") {
        @Override
        public void onClick(View v) {
            //your code
        }
    };
    return super.onCreateOptionsMenu(menu);
}

could not found `getSupportMenuInflater()`? – Nere Feb 12 '18 at 07:13 — Nere, Feb 12 '18 at 07:13

Issues on onCreateOptionsMenu for android.view.View android.view.View.findViewById(int) on a null object reference

2 Answers2