SavedInstanceState总是空的片段 [英] SavedInstanceState is always null in fragment

问题描述

予有使用XML（和的setContentView（）中活性）附连到的活性的片段。一有问题，因为我有我的片段非常动态的观点，所以，当方向变化 我必须恢复的看法所有状态。

我有问题，因为我使用这样的事情：

 公共无效的onSaveInstanceState（包outState）{
        super.onSaveInstanceState（outState）;
        outState.putBoolean（恢复，真正的）;
        outState.putInt（nAndroids，2）;
   }
 

但方向变化后，当与参数捆绑savedInstanceState方法调用（如onCreateView等）我savedInstanceState总是空。

我不是在Android一个菜鸟，但是现在我因为这个问题很生气......

 公共无效onViewCreated（查看视图，捆绑savedInstanceState）{
    super.onViewCreated（查看，savedInstanceState）;

    如果（savedInstanceState == NULL）{
        //未便
    } 其他 {
        // smthelse这是从来没有访问，因为包是总是空
    }

    。getListView（）setDivider（getResources（）getDrawable（R.drawable.list_divider））;
}
 

解决方案

所有的问题是，我不声明机器人：ID为XML中的片段。 Android的需要标识或标签来识别存储的片断并复制所有的元素在里面。所以，球员，记住 - 片段的每个实例都需要唯一的ID或者标签

！

此外，当setRetainInstance（真）声明，然后捆绑应该总是返回null。

I have a fragment attached to the activity using XML (and setContentView() in activity). A have a problem because I have very dynamic views in my fragment, so when orientation changes I must restore all states of views.

I have problem because I'm using something like that:

public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putBoolean("restore", true);
        outState.putInt("nAndroids", 2);
   }

But after orientation change when methods with param Bundle savedInstanceState are called (like onCreateView etc) my savedInstanceState is always null.

I'm not a noob in the Android but now I'm very angry because of this problem...

public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    if (savedInstanceState == null) {
        //smth
    } else {
        // smthelse THIS IS NEVER REACHED BECAUSE BUNDLE IS ALWAYS NULL
    }

    getListView().setDivider(getResources().getDrawable(R.drawable.list_divider));
}

解决方案

All the problem was in that I don't declare android:id for the fragment in XML. Android needs ID or TAG to recognize stored fragment and reproduce all elements in it. So guys, remember - every instance of fragment needs unique id or tag!

Also, when setRetainInstance(true) is declared then bundle should always return null.

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