让Fragment成为ViewPager的一页时，FragmentManager会一直保存管理创建好了的Fragment，即使当前不是显示的这一页，Fragment对象也不会被销毁，在后台默默等待重新显示。但如果Fragment不再可见时，它的视图层次会被销毁掉，下次显示时视图会重新创建。
1 FragmentTransaction ft = getFragmentManager().beginTransaction();
2 ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
3 ft.replace(R.id.details, detail);
4 ft.addToBackStack(null);
5 ft.commit();
1 FragmentTransaction ft = getFragmentManager().beginTransaction();
2 //setCustomAnimations()必须位于replace()之前，否则效果不起所中。它的两个参数分别为enter，exit的效果。系统目前提供两个效果，分别为android.R.animator.fade_in和android.R.animator.fade_out
3 ft.setCustomAnimations(R.animator.slide_in_left,R.animator.slide_out_right);
4 ft.addToBackStack(null);
5 ft.replace(R.id.details,"detail");
6 ft.commit();
fragment一定要有一个无参构造函数，如果要给fragment传参，一定要使用Bundle方式传参，而不重载构造函数传参，因为在fragment重新生成的使用不会执行这个带参构造函数，而是执行无参构造函数。
1 public static VechileFrag newInstance(Vehicle vehicle, String userId, boolean isAdd) {
2 VechileFrag mf = new VechileFrag();
3 Bundle args = new Bundle();
4 args.putString("userId", userId);
5 args.putBoolean("isAdd", isAdd);
6 args.putParcelable("vehicle", vehicle);
7 mf.setArguments(args);
8 return mf;
9 }
10
11
12 @Override
13 public void onCreate(Bundle savedInstanceState) {
14 super.onCreate(savedInstanceState);
15 Bundle args = getArguments();
16 if (args != null) {
17 userId = args.getString("userId");
18 isAdd = args.getBoolean("isAdd");
19 vehicle = args.getParcelable("vehicle");
20 if (vehicle == null) {
21 vehicle = new Vehicle();
22 }
23 }
24 }
1 @Override
2 public void onCreate(Bundle savedInstanceState) {
3 super.onCreate(savedInstanceState);
4 setHasOptionsMenu(true);
5 }
Fragment fragment = fragments.get(i);
if(!fragment.isAdded()) {
if(currentIndex!=-1)
fragments.get(currentIndex).onPause();
ft = fm.beginTransaction();
ft.setTransition(android.support.v4.app.FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.add(R.id.framelayout,fragment);
// ft.addToBackStack(null);
ft.commit();
currentIndex=i;
}
else
{
ft = fm.beginTransaction();
fragments.get(currentIndex).onPause();
ft.setTransition(android.support.v4.app.FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.hide(fragments.get(currentIndex));
ft.show(fragments.get(i));
fragments.get(i).onStart();
ft.commit();
currentIndex=i;
}
