getSupportFragmentManager() 和 getChildFragmentManager() 有什么区别? [英] What is difference between getSupportFragmentManager() and getChildFragmentManager()?

问题描述

我的类继承了 Fragment，这就是它不能使用 getSupportFragmentManager() 的原因.我正在使用 getChildFragmentManager 并且它向我显示错误 - IllegalArguementException:未找到 id 的视图...错误.

My class inherits Fragment and that's why it can't use getSupportFragmentManager(). I am using getChildFragmentManager and it is showing me Error - IllegalArguementException: No view found for id... error.

任何指导将不胜感激.

调用AttachmentsListFragment的代码是

Code for calling AttachmentsListFragment is

Bundle b = new Bundle();
b.putSerializable("AttachmentsList", msg.attachments);  
        AttachmentListFragment listfrag = new AttachmentListFragment(msg.attachments);
FragmentTransaction transaction = getFragmentManager().beginTransaction();       
transaction.add(R.id.attachmentslistcontainer, listfrag);
transaction.addToBackStack(null);
transaction.commit();

attachmentslayout.xml 是

attachmentslayout.xml is

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/attachmentslistcontainer"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textViewAttachmentHeader"
        style="@style/Normal.Header.Toolbar"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="@color/list_separator_background"
        android:ellipsize="end"
        android:gravity="center"
        android:maxLines="2"
        android:text="@string/attachments_header"
        android:textColor="#FFFFFFFF"
        android:textSize="22sp"
        android:textStyle="bold"
        android:visibility="visible" />

    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >
    </ListView>

</FrameLayout>

AttachmentsListFragment.java

AttachmentsListFragment.java

public class AttachmentListFragment extends ListFragment implements IAttachmentsData {

    ArrayList<Attachments> items = null;
    Integer cellLayoutID;
    Integer index;

    public AttachmentListFragment() {

    }

    public AttachmentListFragment(ArrayList<Attachments> items) {
        this.items = items;
        Log.i("Logging", "Items size" + items.size()); //$NON-NLS-1$
    }


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Bundle bundle;
        if (savedInstanceState != null) {
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        //super.onCreateView(inflater, container, savedInstanceState);

        //  setContentView(R.layout.attachmentslayout);
        View view = inflater.inflate(R.layout.attachmentslayout, container, false);
        return view;
    }


    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        setListAdapter(new AttachmentAdapter(
                getActivity().getApplicationContext(),
                R.layout.attachmentslistcellcontent,
                items));
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        // TODO Auto-generated method stub
        super.onListItemClick(l, v, position, id);
        index = position;
        Intent intent = new Intent();
        Bundle b = new Bundle();
        b.putByteArray("Data", items.get(position).getImageData());
        intent.putExtras(b);
    }


    public byte[] getData() {
        // TODO Auto-generated method stub
        if (items != null && index < items.size()) {

            return items.get(index).getImageData();
        }
            return null;
    }

}

推荐答案

getChildFragmentManager()的定义是:

返回一个私有的 FragmentManager 用于放置和管理 Fragment在这个 Fragment 里面.

Return a private FragmentManager for placing and managing Fragments inside of this Fragment.

同时getFragmentManager()(或在本例中getSupportFragmentManager())的定义是:

Meanwhile the definition of getFragmentManager() (or in this case getSupportFragmentManager()) is:

返回 FragmentManager 用于与关联的片段进行交互与此片段的活动.

Return the FragmentManager for interacting with fragments associated with this fragment's activity.

基本上，不同之处在于 Fragment 现在有自己的内部 FragmentManager 可以处理 Fragment.子 FragmentManager 是处理只包含在它被添加到的 Fragment 中的 Fragment 的那个.另一个 FragmentManager 包含在整个 Activity 中.

Basically, the difference is that Fragment's now have their own internal FragmentManager that can handle Fragments. The child FragmentManager is the one that handles Fragments contained within only the Fragment that it was added to. The other FragmentManager is contained within the entire Activity.

在这种情况下，我猜您已经将 Fragments 添加到 Activity 的 FragmentManager.您将获得不包含您要查找的内容的子 FragmentManager.因此，您会收到异常，因为它无法找到具有给定 ID 的 Fragment，因为它位于不同的 FragmentManager 中.

In this case, what I'm guessing is you've added the Fragments to the Activity's FragmentManager. You get the child FragmentManager which doesn't contain what you are looking for. Thus you get the exception because it can't find the Fragment with the given ID because it's in a different FragmentManager.

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