android - getSupportFragmentManager().putFragment 问题

Question

我正在开发一个 android 应用程序，我想保存我在矢量 fragment 中的 fragment 。当我在 onSaveIstanceState 中使用 putFragment 时，系统抛出 IllegalStateException

@Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        // Salviamo lo stato 


        //salvo all fragment
        for(int i=0;i<fragments.size();i++)
            getSupportFragmentManager().putFragment(outState, Integer.toString(i), fragments.get(i));

    }

这是日志:

09-13 10:38:10.230: E/AndroidRuntime(24089): java.lang.IllegalStateException: Fragment GenericPageFragment{417716e0} is not currently in the FragmentManager
09-13 10:38:10.230: E/AndroidRuntime(24089):    at android.support.v4.app.FragmentManagerImpl.putFragment(FragmentManager.java:516)
09-13 10:38:10.230: E/AndroidRuntime(24089):    at it.intects.dashboard.droid.BaseActivity.onSaveInstanceState(BaseActivity.java:180)
09-13 10:38:10.230: E/AndroidRuntime(24089):    at android.app.Activity.performSaveInstanceState(Activity.java:1113)
09-13 10:38:10.230: E/AndroidRuntime(24089):    at android.app.Instrumentation.callActivityOnSaveInstanceState(Instrumentation.java:1188)

为什么？我该如何解决这个错误？

Answer 1

调用 savedInstanceState() 后，您不能进行任何 fragment 事务。

当 Activity 返回时，Activity 将恢复最后附加的 fragment 。

如果您想对 fragment 执行任何操作，请使用:

getSupportFragmentManager().beginTransaction().add(R.layout.container,new MyFragment(), "fragment_tag").commit();

A very good tutorial about fragments