我有3个片段A,B,C.我写了一段代码来替换它们并维护backstack：
public void addFragment(Fragment fragmentToAdd,String fragmentTag) {
FragmentManager supportFragmentManager = getSupportFragmentManager();
Fragment activeFragment = getActiveFragment();
FragmentTransaction fragmentTransaction = supportFragmentManager
.beginTransaction();
if (null != activeFragment) {
fragmentTransaction.hide(activeFragment);
}
fragmentTransaction.replace(R.id.layout_child_activity,fragmentToAdd,fragmentTag);
if (supportFragmentManager.getBackStackEntryCount() > 1) {
supportFragmentManager.popBackStack();
}
fragmentTransaction.addToBackStack(fragmentTag);
fragmentTransaction.commit();
}
在这段代码中
if (supportFragmentManager.getBackStackEntryCount() > 1) {
supportFragmentManager.popBackStack();
}
如果堆栈长度大于1,我使用pop来获取最新的片段.现在由于这个,当长度大于1时,它会一次又一次地调用onCreate视图.
喜欢 ：
>打开A.
>开放B.
>打开C.(如果打开C. onCreateView的A被调用.)
解决方法
正如文档所说,正如行为是正常的,来自后台交易. Backstack,从不保存Fragments,它只是保存事务
http://developer.android.com/intl/es/guide/components/fragments.html
我做了什么,我不确定它是否是最好的方式,但是
当我想清除我做的所有交易
1)在您的活动中检查后堆栈中是否有任何交易,
并在你的片段中添加一个标志,在你的情况下是A.
int backStackCount = getSupportFragmentManager().getBackStackEntryCount();
if(backStackCount > 0) {
Transactions.MUST_DETACH_FROM_BACKSTACK = true;
getSupportFragmentManager().popBackStackImmediate(null,FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
2)在你的片段A里面,获取标志并删除fragent onCreateView并像这样返回null
public class Transactions extends android.support.v4.app.Fragment{
public static boolean MUST_DETACH_FROM_BACKSTACK = false;
public Transactions() {
// required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
Log.i("FRAGMENT","onCreateView "+MUST_DETACH_FROM_BACKSTACK);
// Inflate the layout for this fragment
if (MUST_DETACH_FROM_BACKSTACK) {
MUST_DETACH_FROM_BACKSTACK = false;
getActivity().getSupportFragmentManager().beginTransaction().remove(this).commit();
return null;
}
return inflater.inflate(R.layout.fragment_transactions,container,false);
}
@Override
public void onViewCreated(View view,Bundle savedInstanceState) {
super.onViewCreated(view,savedInstanceState);
Log.i("FRAGMENT","onViewCreated");
if(view != null){
Log.i("FRAGMENT","ThreadStarted");
startThread(view);
}
}
但要小心我得到onResume()之后调用
OnCreateView()
即使使用getActivity().getSupportFragmentManager().beginTransaction().remove(this).commit();
因此,如果你有任何conde onResume方法,你应该适当地处理它
