android销毁当前栈 activity销毁fragment

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西门吹雪 2023-09-19 21:20:46

文章标签 android销毁当前栈 java android xml 3d 文章分类 Android 移动开发

Fragment生命周期的四种状态

Fragment和Activity类似，也存在运行状态、暂停状态、停止状态和销毁状态。

运行状态：当前Fragment位于前台展示，可见，可获取焦点。
暂停状态：其他Activity位于前台，该Fragment可见，不能获取焦点。
停止状态：当前Fragment不可见，失去焦点。
销毁状态：当前Fragment被删除，或所在Activity被结束。

Fragment的回调函数

Fragment为11个，与比Activity不同的有5个。分别为：

onAttach()：在片段已与 Activity 关联时调用（Activity 传递到此方法内）。
onCreateView()：调用它可创建与片段关联的视图层次结构。
onActivityCreated()：在 Activity 的 onCreate() 方法已返回时调用。
onDestroyView()：在移除与片段关联的视图层次结构时调用。
onDetach()：在取消片段与 Activity 的关联时调用。

与四种状态结合，如下图：

Fragment相当于Activity的一个片段，被包含在Activity中，一个Activity中可含有多个Fragment，一个Fragment也可以附属在多个Activity上Fragment也可包含Fragment。

结合Viewpage、TabLayout、RecyclerView实现多个Fragment的切换以及页面的滑动效果

以下为activity_main.xml布局文件

<?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.google.android.material.tabs.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
        <com.google.android.material.tabs.TabItem
            android:id="@+id/tabItem_follow"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="关注" />
        <com.google.android.material.tabs.TabItem
            android:id="@+id/tabItem_recommend"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="推荐" />
        <com.google.android.material.tabs.TabItem
            android:id="@+id/tabItem_digital"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="数码" />
    </com.google.android.material.tabs.TabLayout>

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/id_page_vp"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

</LinearLayout>

以下为fragment_main.xml布局文件

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

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <Button
        android:id="@+id/close_comment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="375dp"
        android:background="#0000"
        android:visibility="gone"
        tools:visibility="visible" />

    <FrameLayout
        android:id="@+id/comment_frameLayout"
        android:layout_width="match_parent"
        android:layout_height="375dp"
        android:layout_alignParentBottom="true"
        android:visibility="gone" />
</RelativeLayout>

以下为video_data.xml布局文件（RecyclerView所对应的一个item的布局文件）

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/line4"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="15dp"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="51dp"
            android:gravity="center_vertical"
            android:orientation="horizontal">

            <FrameLayout

                android:layout_width="wrap_content"
                android:layout_height="wrap_content">

                <com.example.testapp1.control.RoundImageButton
                    android:id="@+id/imageButton"
                    android:layout_width="50dp"
                    android:layout_height="50dp"
                    android:background="@drawable/cir1"
                    android:scaleType="fitXY" />

                <com.example.testapp1.control.RoundImageButton
                    android:id="@+id/imageButton1"
                    android:layout_width="15dp"
                    android:layout_height="15dp"
                    android:layout_gravity="bottom|right"
                    android:background="@drawable/cir1" />
            </FrameLayout>

            <TextView
                android:id="@+id/tv1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="5dp"
                android:text="某某某博主"
                android:textSize="8pt" />

            <FrameLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content">

                <Button
                    android:id="@+id/button4"
                    android:layout_width="50dp"
                    android:layout_height="30dp"
                    android:background="#00000000"
                    android:text="+关注"
                    android:textColor="@color/design_default_color_error"
                    android:textSize="6pt" />

                <Button
                    android:id="@+id/button44"
                    android:layout_width="50dp"
                    android:layout_height="30dp"
                    android:background="#00000000"
                    android:text="已关注"
                    android:textColor="@android:color/darker_gray"
                    android:textSize="6pt"
                    android:visibility="invisible" />
            </FrameLayout>

        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <TextView
                android:id="@+id/tv4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="20dp"
                android:ellipsize="end"
                android:maxEms="13"
                android:maxLines="2"
                android:text="emmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm"
                android:textColor="@color/black"
                android:textSize="10pt" />
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:gravity="center_vertical"
            android:orientation="horizontal">

            <TextView
                android:id="@+id/tv5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="25万次播放"
                android:textSize="5pt" />

            <FrameLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="180dp">

                <ImageButton
                    android:id="@+id/imageButton2"
                    android:layout_width="20dp"
                    android:layout_height="20dp"
                    android:background="@mipmap/detail_sharebar_like"
                    android:visibility="visible" />

                <ImageButton
                    android:id="@+id/imageButton22"
                    android:layout_width="20dp"
                    android:layout_height="20dp"
                    android:background="@mipmap/detail_sharebar_likehighlighted"
                    android:visibility="invisible" />
            </FrameLayout>

            <TextView
                android:id="@+id/tv3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="1dp"
                android:text="22268"
                android:textColor="@color/black"
                android:textSize="6pt" />

            <ImageButton
                android:id="@+id/imageButton3"
                android:layout_width="23dp"
                android:layout_height="23dp"
                android:layout_marginLeft="7dp"
                android:background="@mipmap/comment_immersive_v4_5_white_big"
                tools:src="@android:drawable/ic_menu_view" />

            <TextView
                android:id="@+id/tv6"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="1dp"
                android:text="268"
                android:textColor="@color/black"
                android:textSize="6pt" />

            <ImageButton
                android:id="@+id/imageButton4"
                android:layout_width="23dp"
                android:layout_height="23dp"
                android:layout_marginLeft="7dp"
                android:background="@mipmap/halo_share_icon"
                tools:src="?attr/actionModeShareDrawable" />
        </LinearLayout>
    </LinearLayout>

    <VideoView
        android:id="@+id/video_view"
        android:layout_width="match_parent"
        android:layout_height="250dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:layout_marginTop="10dp"
        android:gravity="center_vertical"
        android:orientation="horizontal">

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recycler_view1"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    </LinearLayout>

    <VideoView
        android:id="@+id/video_view1"
        android:layout_width="match_parent"
        android:layout_height="250dp"
        android:layout_marginTop="25dp" />
</LinearLayout>

以下为MainActivity.java

public class MainActivity extends FragmentActivity {
    private static final String TAG = "--MainActivity---甘---";

    private List<Fragment> mFragmentList = new ArrayList<Fragment>();
    private FragmentAdapter mFragmentAdapter;

    private ViewPager mPageVp;

    private FollowVideoFragment mFollowVideoFragment;
    private RecommendVideoFragment mRecommendVideoFragment;
    private DigitalVideoFragment mDigitalVideoFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "-----------onCreate-------------");
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mPageVp = this.findViewById(R.id.id_page_vp);
        //绑定viewpage与TabLayout
        TabLayout tabLayout = findViewById(R.id.tabs);
        mPageVp.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mPageVp));

        init();
    }

    private void init() {
        mFollowVideoFragment = new FollowVideoFragment();
        mRecommendVideoFragment = new RecommendVideoFragment();
        mDigitalVideoFragment = new DigitalVideoFragment();

        mFragmentList.add(mFollowVideoFragment);
        mFragmentList.add(mRecommendVideoFragment);
        mFragmentList.add(mDigitalVideoFragment);

        mFragmentAdapter = new FragmentAdapter(this.getSupportFragmentManager(), mFragmentList);
        mPageVp.setAdapter(mFragmentAdapter);
        mPageVp.setCurrentItem(1);
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.i(TAG, "-----------onStart-------------");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.i(TAG, "-----------onRestart-------------");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.i(TAG, "-----------onResume-------------");
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.i(TAG, "-----------onPause-------------");
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.i(TAG, "-----------onStop-------------");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.i(TAG, "-----------onDestroy-------------");
    }

}

以下为FollowVideoFragment.java

public class FollowVideoFragment extends Fragment {
    private static final String TAG = "--FollowVideoFragment---甘---";

    @Override
    public void onAttach(@NonNull Context context) {
        Log.i(TAG,"--------onAttach---------");
        super.onAttach(context);
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        Log.i(TAG, "--------onCreate---------");
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        Log.i(TAG, "--------onCreateView---------");
        super.onCreateView(inflater, container, savedInstanceState);
        View videoView = inflater.inflate(R.layout.fragment_main, container, false);
        //此处通过RecyclerView实现页面的滑动效果
        RecyclerView recyclerView = videoView.findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        LinearLayoutManager layoutManager = new LinearLayoutManager(videoView.getContext());
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setAdapter(adapter);
        return videoView;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        Log.i(TAG, "--------onActivityCreated---------");
        super.onActivityCreated(savedInstanceState);
    }

    @Override
    public void onStart() {
        Log.i(TAG, "--------onStart---------");
        super.onStart();
    }

    @Override
    public void onResume() {
        Log.i(TAG, "--------onResume---------");
        super.onResume();
    }

    @Override
    public void onPause() {
        Log.i(TAG, "--------onPause---------");
        super.onPause();
    }

    @Override
    public void onStop() {
        Log.i(TAG, "--------onStop---------");
        super.onStop();
    }

    @Override
    public void onDestroyView() {
        Log.i(TAG, "--------onDestroyView---------");
        super.onDestroyView();
    }

    @Override
    public void onDestroy() {
        Log.i(TAG, "--------onDestroy---------");
        super.onDestroy();
    }

    @Override
    public void onDetach() {
        Log.i(TAG, "--------onDetach---------");
        super.onDetach();
    }

其他两个Fragment的代码和FollowVideoFragment几乎一样，此处不在列出。此处三个Fragment对应同一Adapter(适配器)，每一个Fragment都要有与其对应的适配器。本人在Adapter后还建立了holder用于对应一个item的绑定数据。
VideoAdapter.java

public class VideoAdapter extends RecyclerView.Adapter<VideoViewHolder> {

    private List<BaseData> dataList;
    private Context mContext;

    public VideoAdapter(List<BaseData> list, Context context) {
        dataList = list;
        mContext = context;
    }
    //为RecyclerView的item创建view
    @Override
    public VideoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View viewVideo = LayoutInflater.from(parent.getContext()).inflate(R.layout.video_data, parent, false);
        VideoViewHolder videoViewHolder = new VideoViewHolder(viewVideo, mContext);
                return videoViewHolder;
    }

//为item绑定数据
    @Override
    public void onBindViewHolder(VideoViewHolder holder, int position) {
        holder.bindData(dataList.get(position));
    }

    @Override
    public int getItemCount() {
        return dataList.size();
    }
}

VideoViewHolder.java，因本人demo的实体类数据不同且需放同一list中，并为绑定数据方便，实现多态，封装了一个BaseHolder的方法，读者可将继承改为RecyclerView.ViewHolder

public class VideoViewHolder extends RecyclerView.ViewHolder<VideoData> {
    private VideoView videoView;
    
    TextView personName;
    //RoundImageButton与RoundImageButton是自定义控件
    RoundImageButton personHeadId;
    RoundImageButton personLevelid;
    TextView personIntroduction;
    TextView videoNumber;
    TextView goodNumber;
    TextView commentNumber;
    VideoView video1;
    VideoView video2;
    RecyclerView recyclerView;

    private Context mContext;
    @Override
    public void bindData(VideoData videoData) {
        personName.setText(videoData.getName());
        personHeadId.setImageResource(videoData.getHeadId());
        personLevelid.setImageResource(videoData.getLevelId());
        personIntroduction.setText(videoData.getIntroduction());
        videoNumber.setText(videoData.getVideoNumber());
        goodNumber.setText(videoData.getGoodNumber());
        commentNumber.setText(videoData.getCommentNumber());
       itemView.findViewById(R.id.imageButton4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(view.getContext(), NextActivity.class);
                view.getContext().startActivity(intent);
            }
        });
        
    }
    public VideoViewHolder(View view, Context mContext) {
        super(view);
        this.mContext = mContext;
        personName = view.findViewById(R.id.tv1);
        personHeadId = view.findViewById(R.id.imageButton);
        personLevelid = view.findViewById(R.id.imageButton1);
        personIntroduction = view.findViewById(R.id.tv4);
        videoNumber = view.findViewById(R.id.tv5);
        goodNumber = view.findViewById(R.id.tv3);
        commentNumber = view.findViewById(R.id.tv6);
        video1 = view.findViewById(R.id.video_view);
        video2 = view.findViewById(R.id.video_view1);
        recyclerView = view.findViewById(R.id.recycler_view1);
    }


}

tips：以上代码可能有些绕，简单来说就是Activity包含Fragment，又因为想实现滑动效果，Fragment中包含了RecyclerView，Adapter作为适配器为RecyclerView创建item对应的view并可绑定数据（holder的代码可以放入其中），holder为item绑定数据。