CODEWITHSUNDEEP
androidandroid-layoutandroid-fragmentsandroid-viewpagerruntimeexception
Alexander Farber
Alexander Farber

Reputation: 22988

Inflating ViewPager from XML layout

I am following the Android Programming: The Big Nerd Ranch Guide and there is an example using ViewPager through the 2 files:

The file res/values/ids.xml defines an id in XML:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item type="id" name="viewPager" />
</resources>

And the Java source file CrimePagerActivity.java uses that id:

public class CrimePagerActivity extends FragmentActivity {
    private ViewPager mViewPager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mViewPager = new ViewPager(this);
        mViewPager.setId(R.id.viewPager);
        setContentView(mViewPager);

I have tried to change the example to have a ViewPager object being inflated from an XML layout file res/layout/crime_pager.xml (instead of just using an id):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ViewPager
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/view_pager" />

</LinearLayout>

And then I am trying to use that object in the CrimePagerActivity.java:

public class CrimePagerActivity extends FragmentActivity {
    private ViewPager mViewPager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.crime_pager);
        mViewPager = (ViewPager)findViewById(R.id.view_pager);

Unfortunately, this does not work and fails with a RuntimeException and little info (here fullscreen):

Eclipse screenshot

What is the problem here please?

Upvotes: 1

Views: 2219

Answers (1)

mmlooloo
mmlooloo

Reputation: 18977

change:

<ViewPager
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/view_pager" />

to

<android.support.v4.view.ViewPager
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</android.support.v4.view.ViewPager>

Upvotes: 2

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