一旦顶部的回收视图变大，如何制作固定在布局滚动底部的按钮

Question

我有一个非常基本但困难的问题，我有一个按钮固定在视图底部，但在 recyclerview 容器下方。一旦容器大小增加，我希望按钮位于 recyclerview（可滚动）下方，而不是固定在 view.Is 的底部，有办法实现吗？

我在网上查找了一些想法，但还没有找到任何类似的想法。

我基本上是在用

 <?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:background="@color/white"
    android:clickable="false">

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/cl_root_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipChildren="false">

        <LinearLayout
            android:id="@+id/activity_g"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <android.support.design.widget.AppBarLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:elevation="0dp">


                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:background="@color/white"
                    app:subtitleTextColor="@color/white"
                    app:titleTextAppearance="@style/Toolbar.TitleText"
                    app:titleTextColor="@color/white">


                    <TextView
                        android:id="@+id/nav_back_btn"
                        style="@style/Body1RegLeftBlack"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="20dp"
                        android:layout_marginStart="@dimen/activity_horizontal_margin"
                        android:gravity="center_horizontal"
                        android:background="@drawable/ic_backarrow" />

                    <TextView
                        android:id="@+id/g_main_title"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="18dp"
                        android:layout_marginTop="15dp"
                        android:letterSpacing="0.01"
                        android:gravity="center_horizontal"
                        android:text="@string/g"
                        android:textAppearance="@style/TextAppearance.Text.Roboto.Medium"
                        android:textColor="#de000000"
                        android:textSize="20sp"
                        android:textStyle="normal"

                        />

                </android.support.v7.widget.Toolbar>


            </android.support.design.widget.AppBarLayout>

            <android.support.v4.widget.NestedScrollView
                android:id="@+id/info_scrollview"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <LinearLayout
                    android:id="@+id/infoContainer"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:background="@color/white"
                    android:clickable="false"
                    android:orientation="vertical">

                    <RelativeLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="30dp">

                        <TextView
                            android:id="@+id/info_location"
                            style="@style/Headline2LeftBlack"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginStart="@dimen/activity_horizontal_margin"
                            android:textAppearance="@style/TextAppearance.Text.Chronicle"
                            android:textSize="28sp"
                            tools:text="@string/five_thirty_fifth_ave" />

                        <TextView
                            style="@style/Body1RegRightRed"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_alignBaseline="@+id/info_location"
                            android:layout_alignParentEnd="true"
                            android:layout_marginEnd="@dimen/activity_horizontal_margin"
                            android:layout_toEndOf="@+id/info_location"
                            android:text="@string/location_change"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:visibility="gone" />
                    </RelativeLayout>

                    <LinearLayout
                        android:layout_width="match_parent"
                        android:layout_height="48dp"
                        android:layout_marginTop="44dp"
                        android:gravity="center_vertical"
                        android:weightSum="2">

                        <TextView
                            style="@style/Body1RegLeftBlack"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginStart="16dp"
                            android:layout_weight="1"
                            android:id="@+id/g_start_date"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:text="@string/g_start_date" />

                        <TextView
                            style="@style/Body1RegRightBlack"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginEnd="16dp"
                            android:layout_weight="1"
                            android:id="@+id/g_start_time"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:text="@string/g_start_time" />
                    </LinearLayout>

                    <View
                        android:layout_width="match_parent"
                        android:layout_height="1dp"
                        android:background="@color/registerUserSeparatorColor" />

                    <LinearLayout
                        android:layout_width="match_parent"
                        android:layout_height="48dp"
                        android:gravity="center_vertical"
                        android:weightSum="2">

                        <TextView
                            style="@style/Body1RegLeftBlack"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginStart="16dp"
                            android:layout_weight="1"
                            android:id="@+id/g_end_date"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:visibility="invisible"
                            android:text="@string/g_end_date" />

                        <TextView
                            style="@style/Body1RegRightBlack"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginEnd="16dp"
                            android:layout_weight="1"
                            android:id="@+id/g_end_time"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:text="@string/g_end_time" />
                    </LinearLayout>

                    <View
                        android:layout_width="match_parent"
                        android:layout_height="1dp"
                        android:background="@color/registerUserSeparatorColor" />


                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="16dp"
                        android:layout_marginTop="28dp"
                        android:letterSpacing="0.01"
                        android:lineSpacingExtra="4sp"
                        android:paddingTop="30dp"
                        android:textAppearance="@style/TextAppearance.Text.Roboto.Medium"
                        android:textColor="@color/black"
                        android:textSize="20sp"
                        android:textStyle="normal"
                        android:text="@string/g" />


                    <android.support.v7.widget.RecyclerView
                        android:id="@+id/g_item_list"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:overScrollMode="never"
                        android:divider="@null"
                        tools:listitem="@layout/item_g"/>

                    <TextView
                        style="@style/Body1RegLeftRed"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="16sp"
                        android:layout_marginTop="20dp"
                        android:id="@+id/add_g"
                        android:lineHeight="22sp"
                        android:text="@string/add_g"
                        android:textSize="16sp" />

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="16dp"
                        android:layout_marginTop="58dp"
                        android:letterSpacing="0.01"
                        android:lineSpacingExtra="4sp"
                        android:visibility="invisible"
                        android:textAppearance="@style/TextAppearance.Text.Roboto.Medium"
                        android:textColor="@color/black"
                        android:textSize="20sp"
                        android:textStyle="normal"
                        android:text="@string/arrival_notifications" />

                    <RelativeLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:visibility="gone"
                        android:id="@+id/text_message_container"
                        android:layout_marginStart="16dp">

                        <TextView
                            android:id="@+id/text_message"
                            style="@style/Body1RegLeftBlack"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginTop="11dp"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:text="@string/text_message" />

                        <TextView
                            style="@style/Body2RegLeftGrey"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_below="@+id/text_message"
                            android:layout_marginTop="2dp"
                            android:id="@+id/tap_phone_number_text"
                            android:textAppearance="@style/TextAppearance.Text.Roboto.Regular"
                            android:text="@string/tap_to_add_a_phone_number" />

                        <android.support.v7.widget.SwitchCompat
                            android:id="@+id/text_message_switch"
                            style="@style/Color1SwitchStyle"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_alignParentEnd="true"
                            android:layout_centerVertical="true"
                            android:layout_marginEnd="16dp" />
                    </RelativeLayout>
                    <View
                        android:layout_width="match_parent"
                        android:layout_height="1dp"
                        android:layout_marginStart="16dp"
                        android:visibility="gone"
                        android:layout_marginTop="11dp"
                        android:background="@color/settingsSeparatorLineColor" />


                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:textSize="16sp"
                        android:layout_marginTop="100dp"
                        android:textAppearance="@style/TextAppearance.Text.Roboto.Medium"
                        android:textStyle="normal"

                        android:letterSpacing="0.07"
                        android:lineSpacingExtra="0sp"
                        android:layout_gravity="center"
                        android:layout_marginBottom="30dp"
                        android:id="@+id/submit_btn"
                        android:text="@string/submit_list"
                        />

                </LinearLayout>
            </android.support.v4.widget.NestedScrollView>
        </LinearLayout>
    </android.support.design.widget.CoordinatorLayout>
</android.support.design.widget.CoordinatorLayout>

上面的问题是，submit_list btn 不会保持固定，如果 recyclerview 增长但视图中仍有足够的 space 空闲。

我想让按钮保持固定并且不滚动，直到 recyclerview 的大小超出底部的某个限制（在屏幕上不再可见），之后按钮相对于recyclerview 的最后一项，不再与底部对齐。有什么想法吗？

举个形象的例子：

如您所见，初始屏幕的提交按钮与底部对齐，其余内容就位。当我添加更多用户时：

它仍然停留在底部，因为 recyclerview 项目仍在屏幕内现在，只要我再添加一项，列表就会向上滚动：

如我所见，我希望它位于回收视图下方，而不是固定在屏幕底部（上面的屏幕截图来自 ios 它工作的地方），想知道我们是否可以对 android?

Answer 1

在布局文件夹中创建 button.xml，显然在其中创建一个按钮。

给你的适配器添加一些东西：

//This will check if the current position is past the last item in your list, 
//if it is then it will return the button layout value to this method

@Override
public int getItemViewType(int pos) {
return (pos == mItems.size()) ? R.layout.button : R.layout.mItem;
}

然后在你的 onCreateViewHolder 中做这样的事情

@Override
public mViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

View itemView;

if(viewType == R.layout.item){
    itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, 
parent, false);
}

else {
    itemView = 
LayoutInflater.from(parent.getContext()).inflate(R.layout.button, parent, 
false);
}

return new mViewHolder(itemView);
}

并且在你的 OnBindViewHolder

@Override
public void onBindViewHolder(mViewHolder mHolder, int pos) {
if(pos == mItems.size()) {
    mHolder.button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            //Do something....
        }
    });
}
else {
    String members = mItems.get(pos);
    mHolder.title.setText(members);
}
}

同时更改您的 getItemCount 以获取额外的项目（在您的情况下为按钮）

@Override
public int getItemCount() {
return mItems.size() + 1;
}

另外别忘了在 mViewHolder 中找到你的按钮（我猜你已经知道了）mButton = (Button) view.findViewById(R.id.button);

这样就可以了。

Answer 2

See if this works  

  <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
        android:layout_height="match_parent">
        <ScrollView
            android:layout_width="match_parent"
            android:layout_height="match_parent">
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">
            <android.support.v7.widget.RecyclerView
                android:layout_width="match_parent"
                android:layout_height="match_parent"/>
            <Button
                android:layout_alignParentBottom="true"
                android:text="button"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
        </RelativeLayout>
        </ScrollView>

    </RelativeLayout>

Answer 3

如果你不想做分页那么你可以试试下面的布局文件

<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rvItem"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:nestedScrollingEnabled="false"
        tools:itemCount="5"
        tools:listitem="@layout/item_recycler_tasker_home" />

    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/rvItem"
        android:layout_centerHorizontal="true"
        android:text="MyButton" />
</RelativeLayout>

通过这样做，所有 recyclerview 的项目都会一次性加载，因为 recyclerView 的高度是 wrap_content 它将只获取所有项目所需的高度，然后在 recyclerview 之后你可以看到你的按钮

Answer 4

这是一个demo link

还有一个Gif link

public class WeirdStickyBottomActivity extends AppCompatActivity {

    private RecyclerView mRecyclerView;
    private TextView mStickyView;
    private LinearLayoutManager mLayoutManager;
    private MyAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_weird_sticky_bottom);

        mRecyclerView = findViewById(R.id.recyclerview);
        mStickyView = findViewById(R.id.sticky);
        Button mAddButton = findViewById(R.id.button_add);
        Button mDeleteButton = findViewById(R.id.button_delete);

        mLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
        mAdapter = new MyAdapter(this);
        mRecyclerView.setAdapter(mAdapter);
        hideStickyLayoutIfNeed();

        mAddButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mAdapter.addItems();
                hideStickyLayoutIfNeed();
            }
        });

        mDeleteButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mAdapter.deleteItems();
                hideStickyLayoutIfNeed();
            }
        });

        mStickyView.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Toast.makeText(WeirdStickyBottomActivity.this, "Sticky Click", Toast.LENGTH_SHORT).show();
            }
        });
    }

    private void hideStickyLayoutIfNeed() {
        mRecyclerView.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
            @Override
            public boolean onPreDraw() {
                mRecyclerView.getViewTreeObserver().removeOnPreDrawListener(this);
                int firstVisible = mLayoutManager.findFirstVisibleItemPosition();
                int lastCompletelyVisible = mLayoutManager.findLastCompletelyVisibleItemPosition();

                //adapter list size display beyond the screen
                if (firstVisible > 0 || lastCompletelyVisible < mAdapter.getItemCount() - 1) {
                    mAdapter.addStickyItem(true);
                    if (mStickyView.getVisibility() == View.VISIBLE) {
                        mStickyView.setVisibility(View.GONE);
                    }
                } else if (firstVisible == 0 && lastCompletelyVisible == mAdapter.getItemCount() - 1) {
                    if (mStickyView.getVisibility() != View.VISIBLE) {
                        mStickyView.setVisibility(View.VISIBLE);
                    }
                }
                mRecyclerView.smoothScrollToPosition(mAdapter.getItemCount() - 1);
                return true;
            }
        });
    }

    private static class MyAdapter extends RecyclerView.Adapter<ItemHolder> {

        private int mStickyIndex = -1;

        static final int HOLDER_TYPE_NORMAL = 1;
        static final int HOLDER_TYPE_STICKY = 2;

        private List<String> dataList = new ArrayList<>();
        private Context mContext;

        MyAdapter(Context context) {
            this.mContext = context;
            addItems();
        }

        public void addItems() {
            boolean hasStickyItem = mStickyIndex > 0;
            if (hasStickyItem) {
                dataList.remove(mStickyIndex);
                mStickyIndex = -1;
            }
            int size = dataList.size();
            for (int i = size; i < size + 5; i++) {
                dataList.add("This is a item");
            }
            notifyDataSetChanged();
        }

        public void deleteItems() {
            int size = dataList.size();
            if (size < 6) {
                return;
            }
            boolean hasStickyItem = mStickyIndex > 0;
            if (hasStickyItem) {
                dataList.remove(mStickyIndex);
                mStickyIndex = -1;
            }
            if (size > size - 5) {
                dataList.subList(size - 5, size - 1).clear();
            }
            notifyDataSetChanged();
        }

        public void addStickyItem(boolean notify) {
            //did not add sticky item before
            if (mStickyIndex <= 0) {
                mStickyIndex = dataList.size();
                dataList.add(mContext.getResources().getString(R.string.sticky_layout));
                if (notify) {
                    notifyDataSetChanged();
                }
            }
        }

        @NonNull
        @Override
        public ItemHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            return ItemHolder.create(parent, viewType == HOLDER_TYPE_STICKY);
        }

        @Override
        public void onBindViewHolder(@NonNull ItemHolder holder, int position) {
            holder.bind(dataList.get(position));
        }

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

        @Override
        public int getItemViewType(int position) {

            if (position == mStickyIndex) {
                return HOLDER_TYPE_STICKY;
            }

            return HOLDER_TYPE_NORMAL;
        }
    }

    private static class ItemHolder extends RecyclerView.ViewHolder {

        private TextView textView;
        private boolean isSticky;

        private ItemHolder(@NonNull View itemView, boolean isSticky) {
            super(itemView);
            textView = itemView.findViewById(R.id.text);
            this.isSticky = isSticky;
        }

        void bind(String text) {
           textView.setText(text);
            if (isSticky) {
                textView.setOnClickListener(new View.OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        Toast.makeText(v.getContext(), "Sticky Click", Toast.LENGTH_SHORT).show();
                    }
                });
                textView.setBackgroundColor(textView.getResources().getColor(R.color.colorPrimary));
            } else {
                textView.setOnClickListener(null);
                textView.setBackgroundColor(Color.WHITE);
            }
        }

        static ItemHolder create(ViewGroup parent, boolean isSticky) {
            return new ItemHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_item, parent, false), isSticky);
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true"
        android:orientation="vertical"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:layout_behavior="android.support.design.widget.AppBarLayout$Behavior">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/toolbar_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleMarginEnd="64dp"
            app:expandedTitleMarginStart="48dp"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:title="Collapse">

            <android.support.v7.widget.Toolbar
                android:id="@+id/tb_toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:title="@string/app_name">

                <Button
                    android:id="@+id/button_add"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/button_add" />

                <Button
                    android:id="@+id/button_delete"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/button_delete" />


            </android.support.v7.widget.Toolbar>

        </android.support.design.widget.CollapsingToolbarLayout>

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:id="@+id/sticky_parent"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/recyclerview"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <TextView
            android:id="@+id/sticky"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_gravity="bottom"
            android:background="@color/colorPrimary"
            android:gravity="center"
            android:text="@string/sticky_layout" />

    </FrameLayout>

</android.support.design.widget.CoordinatorLayout>

Answer 5

您可以使用 ConstraintLayout

实现此目的

示例代码

layout file

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">


    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/myRecyclerView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_margin="8dp"
        app:layout_constraintBottom_toTopOf="@+id/btnBottom"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHeight_default="wrap"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/btnBottom"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="12dp"
        android:layout_marginRight="20dp"
        android:padding="12dp"
        android:text="Continue"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        android:textColor="@android:color/white"
        app:backgroundTint="@color/colorPrimary" />

</androidx.constraintlayout.widget.ConstraintLayout>

Activity code

public class MainActivity extends AppCompatActivity {

    RecyclerView myRecyclerView;
    ArrayList<String> arrayList = new ArrayList<>();
    DataAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        myRecyclerView = findViewById(R.id.myRecyclerView);
        myRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        myRecyclerView.setHasFixedSize(true);

        addDataToList();

        adapter = new DataAdapter(this, arrayList);
        myRecyclerView.setAdapter(adapter);

    }

    private void addDataToList() {
        for (int i = 0; i < 5; i++) {
            arrayList.add("NILU_PILU :-> " + i);
        }
    }

}

DataAdapter class

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.ArrayList;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

public class DataAdapter extends RecyclerView.Adapter<DataAdapter.ViewHolder> {

    ArrayList<String> arrayList = new ArrayList<>();
    private Context mContext;

    public DataAdapter(Context mContext, ArrayList<String> arrayList) {
        this.mContext = mContext;
        this.arrayList = arrayList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.aaa, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.tvText.setText(arrayList.get(position));
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView tvText;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            tvText = itemView.findViewById(R.id.tvText);
        }
    }
}

OUTPUTS

一旦顶部的回收视图变大，如何制作固定在布局滚动底部的按钮

How do I make my button which is fixed at the bottom of a layout scroll, once the recyclerview on top grows in size

android

android-layout

android-recyclerview

android-appcompat

android-button