我正在使用PagerSlidingTabStrip
库进行ViewPager
https://github.com/astuetz/PagerSlidingTabStrip。我想在滚动时更改片段。我用下面的代码实现了这个目标。
main活动.java
public class MainActivity extends SherlockFragmentActivity {
private MyPagerAdapter adapter;
ViewPager pager;
private PagerSlidingTabStrip tabs;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabs = (PagerSlidingTabStrip) findViewById(R.id.tabs);
pager = (ViewPager) findViewById(R.id.pager);
adapter = new MyPagerAdapter(getSupportFragmentManager());
pager.setAdapter(adapter);
final int pageMargin = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 4, getResources()
.getDisplayMetrics());
pager.setPageMargin(pageMargin);
tabs.setViewPager(pager);
}
public class MyPagerAdapter extends FragmentPagerAdapter {
private final String[] TITLES = {"First","Second","Third"};
private SherlockFragment[] fragments = new SherlockFragment[] { new FirstFragment(), new SecondFragment(), new ThirdFragment()};
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public CharSequence getPageTitle(int position) {
return TITLES[position];
}
@Override
public int getCount() {
return TITLES.length;
}
@Override
public Fragment getItem(int position) {
return fragments[position];
}
}
}
firstfragment.java文件
public class FirstFragment extends SherlockFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_main, container, false);
Toast.makeText(getSherlockActivity(), "This is from first", Toast.LENGTH_SHORT).show();
return v;
}
}
第二片段.java
public class SecondFragment extends SherlockFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_main, container, false);
Toast.makeText(getSherlockActivity(), "SecondFragment", Toast.LENGTH_SHORT).show();
return v;
}
}
第三部分.java
public class ThirdFragment extends SherlockFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_main, container, false);
Toast.makeText(getSherlockActivity(), "ThirdFragment", Toast.LENGTH_SHORT).show();
return v;
}
}
我拿到了三块碎片,正在用烤面包机测试。
当应用程序以main活动打开时,firstfragment附加到
Activity
,但它显示两个toast,一个来自firstfragment,另一个来自secondfragment,当我滚动到second选项卡时,它显示thirdfragment的toast。所以,我想是这样的。如果我从左向右滚动,将显示从右到当前片段的片段,如果我从右向左滚动,将显示从左到当前片段的片段。请帮忙。
谢谢。
最佳答案
这是因为片段缓存。当您访问某些片段时,也会创建与之对应的同级片段(调用oncreate())。