R.id.container not resolved

Question

I bought book Bill Phillips & Brian Hardy "Android programming the big nerd ranch guide". And in the first chapter, I created Gradle solution using idea instead eclipse. This project generated by idea doesn't compile.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_quiz);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new DummyFragment())
                    .commit();
        }
    }

xml:

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".QuizActivity$DummyFragment">

<TextView
    android:text="@string/hello_world"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

error: cannot find symbol variable container

I have not changed anything, but project doesn't compile

Please help me.

Answer 1

as i mention in comment you must add following code in to your layout:

 android:id = "@+id/container" 

you get that error because you don't have container id in your xml file