Question

我有三种不同的布局cardsListLayout，titleLayout和cardMagazineLayout，将来可能还会有更多布局，它们将用作onCreateViewHolder方法的视图。

我想在onCreateViewHolder方法之间切换视图，以便当用户从AlertDialog列表中选择时

在MainActivity中选中此onOptionsItem的地方，有菜单项“更改布局”，以便当用户按下菜单时，它会显示AlertDialog列表

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.change_layout) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle(getString(R.string.choose_layout));

            String[] layouts = {"Title Layout", "Cards List", "Card Magazine Layout"};
            builder.setItems(layouts, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int index) {
                    switch (index) {
                        case 0: // Title layout
                            Toast.makeText(MainActivity.this,
                                    "Title layout", Toast.LENGTH_LONG).show();
                            break;
                        case 1: // Cards List
                            Toast.makeText(MainActivity.this,
                                    "Card list", Toast.LENGTH_LONG).show();
                            break;
                        case 2: // Cards Magazine Layout
                            Toast.makeText(MainActivity.this,
                                    "Card Magazine Layout", Toast.LENGTH_LONG).show();
                    }
                }
            });

这是我的自定义适配器类PostAdapter

public class PostAdapter extends RecyclerView.Adapter<PostAdapter.PostViewHolder> {
    private Context context;
    private List<Item> items;

    public PostAdapter(Context context, List<Item> items) {
        this.context = context;
        this.items = items;
    }

    @NonNull
    @Override
    public PostAdapter.PostViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(context);

// here's the three layouts that I can't switch between it

        View cardsListLayout = inflater.inflate(R.layout.post_item_card_layout, parent, false);
        View titleLayout = inflater.inflate(R.layout.post_item_grid_layout, parent, false);
        View cardMagazineLayout = inflater.inflate(R.layout.card_magazine_layout,parent,false);

        return new PostViewHolder(titleLayout);
    }

    @Override
    public void onBindViewHolder(@NonNull PostViewHolder holder, int position) {
        final Item item = items.get(position);
        holder.postTitle.setText(item.getTitle());
        final Document document = Jsoup.parse(item.getContent());
        Elements elements = document.select("img");


        Log.e("CODE", "Image: " + elements.get(0).attr("src"));
//        Log.d("Text",document.text());
//        holder.postDescription.setText(document.text());

        Glide.with(context).load(elements.get(0).attr("src"))
                .into(holder.postImage);

        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(context, DetailsActivity.class);
                intent.putExtra("url", item.getUrl());
                intent.putExtra("title", item.getTitle());
                intent.putExtra("content", item.getContent());
                int youtubeThumbnailImagesetVisibility = 0;

                Element element = document.body();

                String youtubeThumbnailImageSrc = "";
                String youTubeLink = "";
                for (Element e : element.getElementsByClass
                        ("YOUTUBE-iframe-video")) {
                    youtubeThumbnailImageSrc = e.attr("data-thumbnail-src");
                    youTubeLink = e.attr("src");
                    Log.e("YouTube thumbnail", youtubeThumbnailImageSrc);
                    Log.e("Youtube link", youTubeLink);
                }

                if (youtubeThumbnailImageSrc.isEmpty()) {
                    youtubeThumbnailImagesetVisibility = 8;
                    intent.putExtra("youtubeThumbnailImagesetVisibility",
                            youtubeThumbnailImagesetVisibility);
                } else {
                    intent.putExtra("youtubeThumbnailImageSrc", youtubeThumbnailImageSrc);
                    intent.putExtra("youTubeLink", youTubeLink);
                }

//             String imageSrc = elements.get(0).attr("src");
//             intent.putExtra("blogImage",imageSrc);

                context.startActivity(intent);
            }
        });

    }

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

    public class PostViewHolder extends RecyclerView.ViewHolder {

        ImageView postImage;
        TextView postTitle;
        TextView postDescription;

        public PostViewHolder(View itemView) {
            super(itemView);
            postImage = itemView.findViewById(R.id.postImage);
            postTitle = itemView.findViewById(R.id.postTitle);
            postDescription = itemView.findViewById(R.id.postDescription);

        }
    }

}

我为每一个创建了两个不同的布局管理器，分别是LinearLayoutManager和GridLayoutManager，目前我使用的是GridLayout，所以我暂时评论了LinearLayoutManger，直到知道如何在它们之间切换为止

//      linearLayoutManager = new LinearLayoutManager(this);
        gridLayoutManager = new GridLayoutManager(this, 2, RecyclerView.VERTICAL, false);
//        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setLayoutManager(gridLayoutManager);

我渴望得到的结果

Answer 1

为防止滚动时出现混合布局，您应该将ViewFlipper与三个不同的RecyclerView结合使用，即每种布局都使用RecyclerView。

第1步：

为这三种布局创建一个公共枚举

public enum ViewType {
    CARD_LIST_LAYOUT, TITLE_LAYOUT, CARD_MAGAZINE_LAYOUT;
}

在PostAdapter中创建一个ViewType变量并将其传递给构造函数，然后通过onCreateViewHolder上的＆else检查是否选择了哪种布局

PostAdapter(Context context, List<Item> items, ViewType viewType) {
        this.context = context;
        this.items = items;
        this.viewType = viewType;
    }



    @NonNull
    @Override
    public PostAdapter.PostViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(context);

        View cardListLayout = inflater.inflate(R.layout.post_item_card_layout, parent, false);
        View titleLayout = inflater.inflate(R.layout.post_item_grid_layout, parent, false);
        View cardMagazineLayout = inflater.inflate(R.layout.card_magazine_layout, parent, false);

        if (this.viewType == ViewType.TITLE_LAYOUT) {
            return new PostViewHolder(titleLayout);
        } else if (this.viewType == ViewType.CARD_LIST_LAYOUT) {
            return new PostViewHolder(cardListLayout);
        } else {
            return new PostViewHolder(cardMagazineLayout);
        }
    }

第2步：

在包含主要RecyclerView的类中创建一个ViewFlipper，其中包含三个子级的Layout和RecyclerView

<ViewFlipper 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:id="@+id/parentLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    >


        <LinearLayout
            android:id="@+id/linearLayout1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

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

                >

            </androidx.recyclerview.widget.RecyclerView>

        </LinearLayout>


        <LinearLayout
            android:id="@+id/linearLayout2"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

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

                >


            </androidx.recyclerview.widget.RecyclerView>

        </LinearLayout>


        <LinearLayout
            android:id="@+id/linearLayout3"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

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

                >

            </androidx.recyclerview.widget.RecyclerView>


        </LinearLayout>

    </RelativeLayout>

</ViewFlipper>

在 MainActivity 中定义变量

         viewFlipper = ((ViewFlipper) findViewById(R.id.parentLayout));


        titleRecyclerView = (RecyclerView) findViewById(R.id.titleRecyclerView);
        cardRecyclerView = (RecyclerView) findViewById(R.id.cardRecyclerView);
        cardMagazineRecyclerView = (RecyclerView) findViewById(R.id.cardMagazineRecyclerView);



        linearLayoutManager1 = new LinearLayoutManager(this);
        cardRecyclerView.setLayoutManager(linearLayoutManager1);
        linearLayoutManager2 = new LinearLayoutManager(this);
        cardMagazineRecyclerView.setLayoutManager(linearLayoutManager2);

        gridLayoutManager = new GridLayoutManager(this, 2, RecyclerView.VERTICAL, false);
        titleRecyclerView.setLayoutManager(gridLayoutManager);


        adapter1 = new PostAdapter(this, items, ViewType.TITLE_LAYOUT);
        titleRecyclerView.setAdapter(adapter1);
        adapter2 = new PostAdapter(this, items, ViewType.CARD_LIST_LAYOUT);
        cardRecyclerView.setAdapter(adapter2);
        adapter3 = new PostAdapter(this, items, ViewType.CARD_MAGAZINE_LAYOUT);
        cardMagazineRecyclerView.setAdapter(adapter3);

为每个RecyclerView添加ScrollListener

titleRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {

                }

            }

            @Override
            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                if (dy > 0) {

                }

            }  
        });

cardRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {

                }

            }

            @Override
            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                if (dy > 0) {

                }

            }  
        });

cardMagazineRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {

                }

            }

            @Override
            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                if (dy > 0) {

                }

            }  
        });

第3步：

最后，在onOptionsItemSelected上单击时在三个布局之间切换

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.change_layout) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle(getString(R.string.choose_layout));

            String[] layouts = {"Title Layout", "Cards List", "Card Magazine Layout"};
            builder.setItems(layouts, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int index) {
                    switch (index) {
                        case 0: // Title layout
                            viewFlipper.setDisplayedChild(0);

                            break;
                        case 1: // Cards List Layout
                            viewFlipper.setDisplayedChild(1);
                            break;
                        case 2: // Cards Magazine Layout
                            viewFlipper.setDisplayedChild(2);
                    }
                }
            });

            AlertDialog dialog = builder.create();
            dialog.show();
            return true;
        }

[重要提示] 您应该对每个布局或RecyclerView进行3次对旧的主RecyclerView的任何实现，例如以上ScrollListener的示例。

希望与您一起工作，如有任何疑问，请通知我

Answer 2

您只需在适配器内部实现 VIEW_TYPE 即可实现。 RecyclerView Adapter public int getViewType(int position)中有一个重写的方法，通常该方法用于将各种类型的视图混合到RecyclerView中。

但是您也可以在您的情况下使用它。首先定义您的视图类型的枚举。然后，在适配器内部维护一个变量以存储当前的viewType，然后从警报对话框项单击中相应地更新该变量。

将当前的viewType值用于onCreateViewHolder和onBindViewHolder方法中，以确定当前应使用的布局以及现在需要更新的UI元素。还要从单击警报对话框的项目中更新RecyclerView布局管理器。

public class PostAdapter extends RecyclerView.Adapter<PostAdapter.PostViewHolder> {

    public enum ViewType {
         VIEW_TYPE_GRID, VIEW_TYPE_CARD, VIEW_TYPE_CARD_MAGAZINE
    }

    private Context context;
    private List<Item> items;
    private ViewType currentViewType;

    public PostAdapter(Context context, List<Item> items, ViewType viewType) {
        this.context = context;
        this.items = items;
        this.currentViewType = viewType;
    }

    // Call this method from alert dialog item click.
    public void updateViewType(ViewType type) {
        this.currentViewType = type;
    }

    @Override
    public int getItemViewType(int position) {
        return this.currentViewType.ordinal();
    }

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

    @Override
    public PostAdapter.PostViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(context);

        // here's the layouts that you want to switch between, based on the viewType
        if (viewType == ViewType.VIEW_TYPE_CARD.ordinal()) {
            View cardLayout = inflater.inflate(R.layout. post_item_card_layout, parent, false);
            return new PostViewHolder(cardLayout);
        }
        else if (viewType == ViewType.VIEW_TYPE_GRID.ordinal()) {
            View gridLayout = inflater.inflate(R.layout. post_item_grid_layout,parent,false);
            return new PostViewHolder(gridLayout);
        }
        else {
            View cardMagazineLayout = inflater.inflate(R.layout. card_magazine_layout, parent, false);
            return new PostViewHolder(cardMagazineLayout);
        }
    }

    @Override
    public void onBindViewHolder(@NonNull PostViewHolder holder, int position) {
        final Item item = items.get(position);
        // Similarly handle different view layout items here based on the viewType returned from getItemViewType method.
        if (getItemViewType(position) == ViewType.VIEW_TYPE_CARD.ordinal()) {

        } else if (getItemViewType(position) == ViewType.VIEW_TYPE_GRID.ordinal()) {

        } else {

        }
    }
}

更新：每次调用updateViewType方法时，您还需要这样调用notifyDataSetChanged方法：

mAdapter.updateViewType(PostAdapter.ViewType.VIEW_TYPE_GRID);
mAdapter.notifyDataSetChanged()

***我已经在设备上测试了此代码，并且可以正常工作。请注意，在放大布局并使用诸如TextView和ImageView之类的布局元素时，应谨慎处理VIEW_TYPE。在我之前的回答中，我将视图类型与错误的布局混合在一起，这可能是唯一的原因，以便您将混合的布局视为输出。

***另外，getItemViewType方法被错误地重命名为getViewType，这是我的代码中导致混合输出的另一个元凶。

Answer 3

为此无需使用多个Recyclerview

您可以将单个Recyclerview与Multiple viewType一起使用

当您想更改Recyclerview的布局时，只需更改LayoutManager中的viewType和Recyclerview即可

示例代码

尝试这种方式

首先为您的多个viewType创建三布局

grid_layout

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="150dp"
    android:layout_height="150dp"
    app:cardElevation="10dp"
    app:cardUseCompatPadding="true">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:adjustViewBounds="true"
            android:contentDescription="@string/app_name"
            android:scaleType="centerCrop"
            android:src="@drawable/dishu" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:background="#6a000000"
            android:gravity="center"
            android:padding="10dp"
            android:text="dummy text"
            android:textColor="@android:color/white" />
    </RelativeLayout>

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

cardlist_layout

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 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"
    app:cardElevation="10dp"
    app:cardUseCompatPadding="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:orientation="vertical">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:adjustViewBounds="true"
            android:contentDescription="@string/app_name"
            android:scaleType="centerCrop"
            android:src="@drawable/dishu" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingStart="5dp"
            android:paddingEnd="10dp"
            android:text="Dummy Title"
            android:textColor="@android:color/black"
            android:textStyle="bold" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingStart="5dp"
            android:paddingEnd="10dp"
            android:text="Dummy Tex" />


    </LinearLayout>
</android.support.v7.widget.CardView>

title_layout

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 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"
    app:cardElevation="10dp"
    app:cardUseCompatPadding="true">

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

        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="vertical">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:paddingStart="5dp"
                android:paddingEnd="5dp"
                android:text="dummy text"
                android:textColor="@android:color/black"
                android:textStyle="bold" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="start"
                android:paddingStart="5dp"
                android:paddingEnd="5dp"
                android:text="I have three different layouts cardsListLayout , titleLayout , cardMagazineLayoutand there may be more in the future, which used as a views on onCreateViewHolder method." />
        </LinearLayout>

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="150dp"
            android:adjustViewBounds="true"
            android:contentDescription="@string/app_name"
            android:scaleType="centerCrop"
            android:src="@drawable/dishu" />


    </LinearLayout>
</android.support.v7.widget.CardView>

DataAdapter

package neel.com.recyclerviewdemo;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

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

    public static final int ITEM_TYPE_GRID = 0;
    public static final int ITEM_TYPE_CARD_LIST = 1;
    public static final int ITEM_TYPE_TITLE_LIST = 2;
    private Context mContext;
    private int VIEW_TYPE = 0;

    public DataAdapter(Context mContext) {
        this.mContext = mContext;
    }

    public void setVIEW_TYPE(int viewType) {
        VIEW_TYPE = viewType;
        notifyDataSetChanged();
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = null;
        // check here the viewType and return RecyclerView.ViewHolder based on view type
        switch (VIEW_TYPE) {
            case ITEM_TYPE_GRID:
                // if VIEW_TYPE is Grid than return GridViewHolder
                view = LayoutInflater.from(mContext).inflate(R.layout.grid_layout, parent, false);
                return new GridViewHolder(view);
            case ITEM_TYPE_CARD_LIST:
                // if VIEW_TYPE is Card List than return CardListViewHolder
                view = LayoutInflater.from(mContext).inflate(R.layout.cardlist_layout, parent, false);
                return new CardListViewHolder(view);
            case ITEM_TYPE_TITLE_LIST:
                // if VIEW_TYPE is Title List than return TitleListViewHolder
                view = LayoutInflater.from(mContext).inflate(R.layout.title_layout, parent, false);
                return new TitleListViewHolder(view);
        }
        return new GridViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        final int itemType = getItemViewType(position);
        // First check here the View Type
        // than set data based on View Type to your recyclerview item
        if (itemType == ITEM_TYPE_GRID) {
        if (holder instanceof CardViewHolder) {
            GridViewHolder viewHolder = (GridViewHolder) holder;
            // write here code for your grid list
      }
        } else if (itemType == ITEM_TYPE_CARD_LIST) {
       if (holder instanceof CardViewHolder) {
            CardListViewHolder buttonViewHolder = (CardListViewHolder) holder;
            // write here code for your grid list
       }
        } else if (itemType == ITEM_TYPE_TITLE_LIST) {
            if (holder instanceof CardViewHolder) {
            TitleListViewHolder buttonViewHolder = (TitleListViewHolder) holder;
            // write here code for your TitleListViewHolder
          }
        }
    }

    @Override
    public int getItemCount() {
        return 40;
    }

    // RecyclerView.ViewHolder class for gridLayoutManager
    public class GridViewHolder extends RecyclerView.ViewHolder {

        public GridViewHolder(@NonNull View itemView) {
            super(itemView);
        }
    }

    // RecyclerView.ViewHolder class for Card list View
    public class CardListViewHolder extends RecyclerView.ViewHolder {

        public CardListViewHolder(@NonNull View itemView) {
            super(itemView);
        }
    }

    // RecyclerView.ViewHolder class for Title list View
    public class TitleListViewHolder extends RecyclerView.ViewHolder {

        public TitleListViewHolder(@NonNull View itemView) {
            super(itemView);
        }
    }
}

MainActivity

package neel.com.recyclerviewdemo;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

    DataAdapter dataAdapter;
    private RecyclerView myRecyclerView;
    private LinearLayoutManager linearLayoutManager;
    private GridLayoutManager gridLayoutManager;

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

        myRecyclerView = findViewById(R.id.myRecyclerView);
        myRecyclerView.setHasFixedSize(true);

        linearLayoutManager = new LinearLayoutManager(this);
        gridLayoutManager = new GridLayoutManager(this, 3);

        myRecyclerView.setLayoutManager(gridLayoutManager);

        dataAdapter = new DataAdapter(this);
        myRecyclerView.setAdapter(dataAdapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.home_menu, menu);
        // return true so that the menu pop up is opened
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        if (item.getItemId() == R.id.action_dialog) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Please choose a layout");

            String[] layouts = {"Title Layout", "Cards List", "Grid View"};
            builder.setItems(layouts, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int index) {
                    switch (index) {
                        case 0: // Title layout
                            dataAdapter.setVIEW_TYPE(2);
                            myRecyclerView.setLayoutManager(linearLayoutManager);
                            myRecyclerView.setAdapter(dataAdapter);
                            break;
                        case 1: // Cards List
                            dataAdapter.setVIEW_TYPE(1);
                            myRecyclerView.setLayoutManager(linearLayoutManager);
                            myRecyclerView.setAdapter(dataAdapter);
                            break;
                        case 2: // Grid  Layout
                            dataAdapter.setVIEW_TYPE(0);
                            myRecyclerView.setLayoutManager(gridLayoutManager);
                            myRecyclerView.setAdapter(dataAdapter);
                    }
                }
            });

            builder.show();
        }
        return super.onOptionsItemSelected(item);
    }
}

activity_main布局

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

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

输出

https://youtu.be/L3slKTy2bzI

Answer 4

不再做。只需在alertdialog单击上更改recyclerview的布局即可。如果要使用网格布局，而不是将其更改为网格布局，请设置LinearLayout并设置adapter.notifydatasetchanged，如果要更改recyclerview Adapter行的布局，则可以在recyclerview的适配器中添加参数化构造函数。之后，读取参数并据此设置视图。就像这样

 public CategoryRecyclerview(List<MainCategory> mainCategories, Context context, FragmentManager fragmentManager,String layouttype) {
    this.context = context;
    layouttype= this.layouttype;}

并将其放在oncreateviewholder中

 if(layouttype.equals("GRID")){
        View view = inflater.inflate(R.layout.grid, viewGroup, false);
        CategoryRecyclerview.Myviewholder viewHolder = new CategoryRecyclerview.Myviewholder(view);
        holders.add(viewHolder);
        return viewHolder;
    }

在notifydataset更改之后。

单击AlertDialog项目列表时，在RecyclerView布局之间切换

4 个答案: