I have been using the v23.0.1 support library until now with no problems. Now when I switch to the new v23.1.0 library I am getting a null pointer on widgets in the drawer layout.
mNavigationView = (NavigationView) findViewById(R.id.navigation_view);
TextView username = (TextView) mNavigationView.findViewById(R.id.username_textView);
// ^^^^^^^^ is now null when using new library
// which causes the following to fail
username.setText(mUser.getName());
activity layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include layout="@layout/toolbar" />
...
</LinearLayout>
<android.support.design.widget.NavigationView
android:id="@+id/navigation_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/drawer_header"
app:menu="@menu/drawer_items" />
</android.support.v4.widget.DrawerLayout>
drawer_header.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:fresco="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="150dp"
android:orientation="vertical">
<TextView
android:id="@+id/username_textView"
android:layout_width="match_parent"
android:layout_height="0dp" />
...
</LinearLayout>
Simply changing the gradle file to use the older version makes it work fine instantly so I don't think there is anything horribly wrong with my code. I checked out the revisions in the update and didn't see anything that I would think to cause this.
Surely this will be affecting others also, any clues?
With the design library v 23.1.0 the NavigationView
works with a RecyclerView
.
Also the Header
is now a type of row.
It means that the header could not be immediately available in the view hierarchy.
It can cause issues if you are using methods like navigationView.findViewById(XXX)
to get a view inside the header.
There is a bug in the Google Tracker.
EDIT 12/10/2015: Design library 23.1.1
The 23.1.1 introduces a new API for retrieving header views for NavigationView with getHeaderView()
BEFORE 23.1.1
workaround fot 23.1.0 can be to use a addOnLayoutChangeListener
. Somenthing like:
navigationView.addOnLayoutChangeListener( new View.OnLayoutChangeListener()
{
@Override
public void onLayoutChange( ... )
{
navigationView.removeOnLayoutChangeListener( this );
View view = navigationView.findViewById( ... );
}
} );
Another possible workaround are:
remove the app:headerLayout
attribute from the xml, and then add the header programatically.
Inflate the headerView programmatically.
Use somenthing like this:
View headerLayout = navigationView.inflateHeaderView(R.layout.navigation_header);
headerLayout.findViewById(xxx);
It appears attaching the header view to the navigation drawer using xml is currently broken. The solution is to inflate and attach the view manually.
activity layout
<android.support.design.widget.NavigationView
android:id="@+id/navigation_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/drawer_header" <!-- remove this line -->
app:menu="@menu/drawer_items" />
Then in your code inflate and attach the header by doing the following.
NavigationView navigationView = (NavigationView) findViewById(R.id.navigation_view);
View drawerHeader = navigationView.inflateHeaderView(R.layout.drawer_header);
TextView username = (TextView) drawerHeader.findViewById(R.id.username_textView);
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