'cannot find symbol variable' in android data binding include layout

Question

layout_content.xml

<layout>
    <android.support.design.widget.AppBarLayout
     android:id="@+id/appbar"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

     <android.support.v7.widget.Toolbar
         android:id="@+id/toolbar"
         android:layout_width="match_parent"
         android:layout_height="?attr/actionBarSize"
         android:background="?attr/colorPrimary"
          />
    </android.support.design.widget.AppBarLayout>
</layout>

layout_main.xml

<layout>
    <android.support.v4.widget.DrawerLayout
    android:id="@+id/dl_main_drawer"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

       <include layout="@layout/layout_content" android:id="@+id/content"/>

    </android.support.v4.widget.DrawerLayout>
</layout>

MainActivity.java

LayoutMainBinding binding = DataBindingUtil.setContentView(this,R.layout.layout_main);
setSupportActionBar(binding.content.toolbar);

Android Studio intellisense check binding.content is ViewDataBinding obj

but build error 'cannot find symbol variable content' Will this have any problem? thx!

This happens when you've renamed a layout file and the old generated Binding class is still hanging around. Try choosing "Build->Clean Project" and then recompile. — George Mount
– George Mount, Commented Jul 28, 2015 at 14:42
I try Clean Project and recompile,but not work. I try reopen Android studio,Also not work. — tatsuyuki
– tatsuyuki, Commented Jul 28, 2015 at 16:07
And i try create new project,but build still show 'cannot find symbol variable content' error — tatsuyuki
– tatsuyuki, Commented Jul 28, 2015 at 16:09

George Mount · Accepted Answer · 2015-07-29 17:17:40Z

14

The layout activity_main.xml:

<layout>
    <android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        tools:context=".MainActivity">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <include layout="@layout/layout_content" android:id="@+id/content" />

        </LinearLayout>
    </android.support.v4.widget.DrawerLayout>
</layout>

generates ActivityMainBinding.java. In your MainActivity.java, you use the generated field for content in the setSupportActionBar argument:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ActivityMainBinding binding = DataBindingUtil.setContentView(this,R.layout.activity_main);
    setSupportActionBar(binding.content.toolbar);
}

Normally a layout will generate public final fields for each of the Views with android:ids and Binding subclasses for each of the includes with IDs. In this case, the data binding system did not detect that the included content @layout/layout_content was a binding layout and thus didn't capture the Binding class for the include.

When a variable is bound to an include, the data binding system will use that to determine that the included layout is a binding layout. So, if your layout had this instead:

<include layout="@layout/layout_content"
         android:id="@+id/content"
         app:someVar="@{someVar}" />

You'd have gotten a content field with the type LayoutContentBinding. This does assume that someVar is declared in both activity_main.xml and layout_content.xml.

The error in Android Studio was pointing to the correct location, but it was difficult to understand. In the future, you can look for the generated binding class in your app/build directory. This may help you figure out what the error means.

I've filed a bug to fix the error -- we should be generating a public final field for the include with the ID.

answered Jul 29, 2015 at 17:17

George Mount

20.9k2 gold badges76 silver badges62 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

tatsuyuki Over a year ago

Now is work,but i think this is not great solution.I hope next update <include layout="@layout/layout_content" android:id="@+id/content" /> is work.Thank you.

KimKha Over a year ago

I reported to issue tracker here code.google.com/p/android/issues/detail?id=186914. Hope it will solve in near future, and they don't delete my that issue.

George Mount Over a year ago

It is solved as of rc2, which went out this week. Enjoy!

Collectives™ on Stack Overflow

'cannot find symbol variable' in android data binding include layout

1 Answer 1

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related