Android ViewPager 显示问题

Android ViewPager display issue

我的 PageTabStrip

顶部有一个 space

这是我 activity 的代码:

mCustomPagerAdapter = new CustomPagerAdapter(getSupportFragmentManager(), this , wpPostGroupsArray, mLastLocation);
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mCustomPagerAdapter);
    mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }

        @Override
        public void onPageSelected(int position) {
            currentItemSelected = position;
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

这对我来说似乎是正确的。那是从哪里来的?

这是 XML 代码:

<?xml version="1.0" encoding="utf-8"?>

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <android.support.v4.view.PagerTabStrip
        android:id="@+id/pager_tab_strip"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="top"
        android:background="@color/action_bar"
        android:paddingBottom="5dp"
        android:paddingTop="5dp"
        android:textColor="#fff" />

</android.support.v4.view.ViewPager>

这一行是问题所在:

actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);