Android:你能嵌套碎片吗？

Question

是否有可能坚持Fragment另一个的布局Fragment？有没人试过这个？

Answer 1

最后!android 4.2更新附带嵌套片段的默认支持,也兼容: 官方NestedFragments.更重要的是,嵌套片段的支持在最新的第11版v4支持库中公布了!

Answer 2

不,片段目前不在层次结构中.试图将一个片段嵌入另一个片段可能会导致问题,通常是微妙的.

Answer 3

编辑:从ACLv11开始,只有replace(...) ViewPagers动态时才需要这样做.

是的,你可以,但有一些方面很痛苦,但我甚至嵌入了FragmentViewPagers.

如果您嵌入XML,那么当布局膨胀时,您将没有任何问题.

如果您在另一个片段中动态嵌入片段,那么您将遇到问题!虽然有可能.

通常涉及发布到处理程序,然后在当前片段转换之后执行然后启动另一个处理程序,这样您就可以非常容易地嵌入片段.但这会导致其他问题,因此您必须小心如何实现这一点.

FoodTestFeast嵌入了ViewPagers,它们被动态删除和添加.

My Base FragmentViewPager - 包含视图寻呼机的片段(具有FragmentPagerAdapter)

我还没有看到任何使用过这种情况的崩溃,但如果有其他人这样做,请告诉我.

/**
 * @project FoodFeast
 * @author chris.jenkins
 * @created Dec 28, 2011
 */
package couk.jenxsolution.food.ui.fragments;

import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.viewpagerindicator.TabPageIndicator;

import couk.jenxsolution.food.R;
import couk.jenxsolution.food.app.FoodApplication;

/**
 * @author chris.jenkins
 */
public class QuizPagerBaseFragment extends QuizBaseFragment
{

    // Data
    private FragmentStatePagerAdapter mAdapter = null;

    // Views
    private int layoutRes;
    private View mRootView;
    private ViewPager mPager;
    private TabPageIndicator mIndicator;

    // Handlers
    private final Handler handler = new Handler();
    private Runnable runPager;
    private boolean mCreated = false;

    /**
     * @see android.support.v4.app.Fragment#onCreateView(android.view.LayoutInflater,
     *      android.view.ViewGroup, android.os.Bundle)
     */
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
        mRootView = inflater.inflate(layoutRes, container, false);
        mPager = (ViewPager) mRootView.findViewById(R.id.pager);
        mPager.setOffscreenPageLimit(2);
        mIndicator = (TabPageIndicator) mRootView.findViewById(R.id.indicator);
        mIndicator.setTypeface(FoodApplication.getInstance().getTFs().getTypeFaceBold());

        return mRootView;
    }

    /**
     * @see android.support.v4.app.Fragment#onActivityCreated(android.os.Bundle)
     */
    @Override
    public void onActivityCreated(Bundle savedInstanceState)
    {
        super.onActivityCreated(savedInstanceState);
        if (runPager != null) handler.post(runPager);
        mCreated = true;
    }

    /**
     * @see android.support.v4.app.Fragment#onPause()
     */
    @Override
    public void onPause()
    {
        super.onPause();
        handler.removeCallbacks(runPager);
    }

    /**
     * Set the ViewPager adapter from this or from a subclass.
     * 
     * @author chris.jenkins
     * @param adapter
     */
    protected void setAdapter(FragmentStatePagerAdapter adapter)
    {
        mAdapter = adapter;
        // mAdapter.notifyDataSetChanged();
        runPager = new Runnable() {

            @Override
            public void run()
            {
                mPager.setAdapter(mAdapter);
                mIndicator.setViewPager(mPager);
                // mAdapter.notifyDataSetChanged();
                mIndicator.setVisibility(View.VISIBLE);
            }
        };
        if (mCreated)
        {
            handler.post(runPager);
        }
    }

    /**
     * Has to be set before onCreateView
     * 
     * @author chris.jenkins
     * @param layoutRes
     */
    protected void setLayoutRes(int layoutRes)
    {
        this.layoutRes = layoutRes;
    }

}

仅供参考你的布局需要看起来像这样(或类似): 注意指标= GONE!

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <com.viewpagerindicator.TabPageIndicator
        android:id="@+id/indicator"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:visibility="gone"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

</LinearLayout>