如何使用 RecyclerView 构建水平的 ListView

Question

我需要在我的 Android 应用程序中实现水平列表视图。我做了一些研究，发现 How can I make a horizontal ListView in Android? and Horizontal ListView in Android?。然而，这些问题是在 Recyclerview 发布之前提出的。现在有没有更好的方法用 Recyclerview 来实现这个？

Answer 1

Is there a better way to implement this now with RecyclerView now?

是的。

当您使用 RecyclerView 时，您需要指定一个 LayoutManager 负责布置视图中的每个项目。 LinearLayoutManager 允许您指定方向，就像正常的 LinearLayout 一样。

要使用 RecyclerView 创建水平列表，您可以这样做：

LinearLayoutManager layoutManager
    = new LinearLayoutManager(requireContext(), LinearLayoutManager.HORIZONTAL, false);

RecyclerView myList = (RecyclerView) findViewById(R.id.my_recycler_view);
myList.setLayoutManager(layoutManager);

Answer 2

有一个名为 HorizontalGridView 的 RecyclerView 子类。您可以使用它来获得水平方向。 VerticalGridView为垂直方向。

Answer 3

尝试构建水平 ListView 花费了太多时间。我已经通过两种方式解决了。

通过使用适配器扩展自 PagerAdapter 的 ViewPager。

像上面一样使用 RecyclerView。我们需要像下面的代码一样应用 LayoutManager:

 LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);

 RecyclerView myList = (RecyclerView) findViewById(R.id.my_recycler_view);
 myList.setLayoutManager(layoutManager);

Answer 4

如果你想用RecyclerView和GridLayoutManager，这是实现水平滚动的方法。

recyclerView.setLayoutManager(
new GridLayoutManager(recyclerView.getContext(), rows, GridLayoutManager.HORIZONTAL, false));

Answer 5

 <android.support.v7.widget.RecyclerView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layoutManager="android.support.v7.widget.LinearLayoutManager" />

Answer 6

随着 RecyclerView 库的发布，现在您可以轻松对齐与文本绑定的图像列表。您可以使用 LinearLayoutManager 来指定您希望将列表定向的方向，垂直或水平，如下所示。

您可以下载完整的working demo from this post。

Answer 7

如果您希望使用 Horizontal Recycler View 作为 ViewPager，那么现在可以借助支持库版本 24.2.0 中添加的 LinearSnapHelper。

首先将 RecyclerView 添加到您的 Activity/Fragment

<android.support.v7.widget.RecyclerView
    android:layout_below="@+id/sign_in_button"
    android:layout_width="match_parent"
    android:orientation="horizontal"
    android:id="@+id/blog_list"
    android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>

在我的例子中，我在 RecyclerView

中使用了 CardView

blog_row.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView

    xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_margin="15dp"
        android:orientation="vertical">

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

            <com.android.volley.toolbox.NetworkImageView
                android:id="@+id/imageBlogPost"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:adjustViewBounds="true"
                android:paddingBottom="15dp"
                android:src="@drawable/common_google_signin_btn_text_light_normal" />

            <TextView
                android:id="@+id/TitleTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
               android:layout_marginBottom="20dp"

                android:text="Post Title Here"
                android:textSize="16sp" />

            <TextView
                android:id="@+id/descriptionTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Post Description Here"
                android:paddingBottom="15dp"
                android:textSize="14sp" />
        </LinearLayout>

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

在你的Activity/Fragment

private RecyclerView mBlogList;

LinearLayoutManager layoutManager =
    new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);

mBlogList = (RecyclerView) findViewById(R.id.blog_list);
mBlogList.setHasFixedSize(true);
mBlogList.setLayoutManager(layoutManager);

LinearSnapHelper snapHelper = new LinearSnapHelper() {
    @Override
    public int findTargetSnapPosition(RecyclerView.LayoutManager lm, int velocityX, int velocityY) {
        View centerView = findSnapView(lm);
        if (centerView == null)
            return RecyclerView.NO_POSITION;

        int position = lm.getPosition(centerView);
        int targetPosition = -1;
        if (lm.canScrollHorizontally()) {
            if (velocityX < 0) {
                targetPosition = position - 1;
            } else {
                targetPosition = position + 1;
            }
        }

        if (lm.canScrollVertically()) {
            if (velocityY < 0) {
                targetPosition = position - 1;
            } else {
                targetPosition = position + 1;
            }
        }

        final int firstItem = 0;
        final int lastItem = lm.getItemCount() - 1;
        targetPosition = Math.min(lastItem, Math.max(targetPosition, firstItem));
        return targetPosition;
    }
};

snapHelper.attachToRecyclerView(mBlogList);

最后一步是将适配器设置为 RecyclerView

mBlogList.setAdapter(firebaseRecyclerAdapter);

Answer 8

完整示例

垂直 RecyclerView 和水平 RecyclerView 之间唯一真正的区别在于设置 LinearLayoutManager 的方式。这是代码片段。完整示例如下。

LinearLayoutManager horizontalLayoutManagaer = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.HORIZONTAL, false);
recyclerView.setLayoutManager(horizontalLayoutManagaer);

这个更完整的例子仿照。

更新 Gradle 依赖项

确保以下依赖项在您的应用 gradle.build 文件中：

implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support:recyclerview-v7:27.1.1'

您可以将版本号更新为 the most current。

创建activity布局

将 RecyclerView 添加到您的 xml 布局。

activity_main.xml

<?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">

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

</RelativeLayout>

创建项目布局

我们 RecyclerView 中的每个项目都将在 TextView 上有一个彩色的 View。新建布局资源文件。

recyclerview_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp">

    <View
        android:id="@+id/colorView"
        android:layout_width="100dp"
        android:layout_height="100dp"/>

    <TextView
        android:id="@+id/tvAnimalName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"/>

</LinearLayout>

创建适配器

RecyclerView 需要一个适配器来用您的数据填充每一行（水平项）中的视图。创建一个新的 java 文件。

MyRecyclerViewAdapter.java

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

    private List<Integer> mViewColors;
    private List<String> mAnimals;
    private LayoutInflater mInflater;
    private ItemClickListener mClickListener;

    // data is passed into the constructor
    MyRecyclerViewAdapter(Context context, List<Integer> colors, List<String> animals) {
        this.mInflater = LayoutInflater.from(context);
        this.mViewColors = colors;
        this.mAnimals = animals;
    }

    // inflates the row layout from xml when needed
    @Override
    @NonNull
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.recyclerview_item, parent, false);
        return new ViewHolder(view);
    }

    // binds the data to the view and textview in each row
    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        int color = mViewColors.get(position);
        String animal = mAnimals.get(position);
        holder.myView.setBackgroundColor(color);
        holder.myTextView.setText(animal);
    }

    // total number of rows
    @Override
    public int getItemCount() {
        return mAnimals.size();
    }

    // stores and recycles views as they are scrolled off screen
    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        View myView;
        TextView myTextView;

        ViewHolder(View itemView) {
            super(itemView);
            myView = itemView.findViewById(R.id.colorView);
            myTextView = itemView.findViewById(R.id.tvAnimalName);
            itemView.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
        }
    }

    // convenience method for getting data at click position
    public String getItem(int id) {
        return mAnimals.get(id);
    }

    // allows clicks events to be caught
    public void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }

    // parent activity will implement this method to respond to click events
    public interface ItemClickListener {
        void onItemClick(View view, int position);
    }
}

备注

虽然不是绝对必要的，但我包含了侦听项目点击事件的功能。这在旧的 ListViews 中可用，并且是一种常见的需求。如果不需要，可以删除此代码。

在 Activity

中初始化 RecyclerView

将以下代码添加到您的主activity。

MainActivity.java

public class MainActivity extends AppCompatActivity implements MyRecyclerViewAdapter.ItemClickListener {

    private MyRecyclerViewAdapter adapter;

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

        // data to populate the RecyclerView with
        ArrayList<Integer> viewColors = new ArrayList<>();
        viewColors.add(Color.BLUE);
        viewColors.add(Color.YELLOW);
        viewColors.add(Color.MAGENTA);
        viewColors.add(Color.RED);
        viewColors.add(Color.BLACK);

        ArrayList<String> animalNames = new ArrayList<>();
        animalNames.add("Horse");
        animalNames.add("Cow");
        animalNames.add("Camel");
        animalNames.add("Sheep");
        animalNames.add("Goat");

        // set up the RecyclerView
        RecyclerView recyclerView = findViewById(R.id.rvAnimals);
        LinearLayoutManager horizontalLayoutManager
                = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(horizontalLayoutManager);
        adapter = new MyRecyclerViewAdapter(this, viewColors, animalNames);
        adapter.setClickListener(this);
        recyclerView.setAdapter(adapter);
    }

    @Override
    public void onItemClick(View view, int position) {
        Toast.makeText(this, "You clicked " + adapter.getItem(position) + " on item position " + position, Toast.LENGTH_SHORT).show();
    }
}

备注

请注意，activity 实现了我们在适配器中定义的 ItemClickListener。这允许我们处理 onItemClick.

完成

就是这样。您现在应该可以运行您的项目并获得类似于顶部图像的内容。

注释

我示例中的彩色视图当然可以用真实项目中的图像替换。

Answer 9

试试这个：

myrecyclerview.setLayoutManager(
        new LinearLayoutManager(getActivity(),
                                LinearLayoutManager.HORIZONTAL,false));
myrecyclerview.setAdapter(recyclerAdapter);

只有在你有一个带有一些片段的回收站视图的情况下。

Answer 10

XML 文件

<HorizontalScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:scrollbars="vertical|horizontal" />

</HorizontalScrollView>

代码

import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;

public class MainActivity extends AppCompatActivity{

    ImageView mImageView1;
    Bitmap bitmap;
    String mSavedInfo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mImageView1 = (ImageView) findViewById(R.id.image);
    }
    public Bitmap getBitmapFromURL(String src) {
        try {
            java.net.URL url = new java.net.URL(src);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
    public void button2(View view) {
        new DownloadImageFromTherad().execute();
    }
    private class DownloadImageFromTherad extends AsyncTask<String, Integer, String> {
        @Override
        protected String doInBackground(String... params) {
            bitmap = getBitmapFromURL("https://cdn.pixabay.com/photo/2016/08/08/09/17/avatar-1577909_960_720.png");
            return null;
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            File sdCardDirectory = Environment.getExternalStorageDirectory();
            File image = new File(sdCardDirectory, "test.png");
            boolean success = false;
            FileOutputStream outStream;
            mSavedInfo = saveToInternalStorage(bitmap);
            if (success) {
                Toast.makeText(getApplicationContext(), "Image saved with success", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(getApplicationContext(), "Error during image saving" + mSavedInfo, Toast.LENGTH_LONG).show();
            }
        }
    }
    private String saveToInternalStorage(Bitmap bitmapImage) {
        ContextWrapper cw = new ContextWrapper(getApplicationContext());
        // path to /data/data/yourapp/app_data/imageDir
        File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
        File mypath = new File(directory, "profile.jpg");
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(mypath);
            bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return directory.getAbsolutePath();
    }
    private void loadImageFromStorage(String path) {
        try {
            File f = new File(path, "profile.jpg");
            Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
            mImageView1.setImageBitmap(b);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
    public void showImage(View view) {
        loadImageFromStorage(mSavedInfo);
    }
    
}

Answer 11

It's for both for Horizontal and for Vertical.

RecyclerView recyclerView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test_recycler);
    recyclerView = (RecyclerView)findViewById(R.id.recyclerViewId);

    RecyclAdapter adapter = new RecyclAdapter();

    //Vertical RecyclerView
    RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
    recyclerView.setLayoutManager(mLayoutManager);

    //Horizontal RecyclerView
    //recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext(),LinearLayoutManager.HORIZONTAL,false));

    recyclerView.setAdapter(adapter);

}

Answer 12

水平动态中的 Recycler 视图。

回收器视图实现

RecyclerView musicList = findViewById(R.id.MusicList);

// RecyclerView musiclist = findViewById(R.id.MusicList1);
// RecyclerView musicLIST = findViewById(R.id.MusicList2);
LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
musicList.setLayoutManager(layoutManager);

String[] names = {"RAP", "CH SHB", "Faheem", "Anum", "Shoaib", "Laiba", "Zoki", "Komal", "Sultan","Mansoob Gull"};
musicList.setAdapter(new ProgrammingAdapter(names));'

用于回收器视图的适配器class，其中有一个用于保存该回收器视图的视图容器

public class ProgrammingAdapter 
     extendsRecyclerView.Adapter<ProgrammingAdapter.programmingViewHolder> {

private String[] data;

public ProgrammingAdapter(String[] data)
{
    this.data = data;
}

@Override
public programmingViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    View view = inflater.inflate(R.layout.list_item_layout, parent, false);

    return new programmingViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull programmingViewHolder holder, int position) {
    String title = data[position];
    holder.textV.setText(title);
}

@Override
public int getItemCount() {
    return data.length;
}

public class programmingViewHolder extends RecyclerView.ViewHolder{
    ImageView img;
    TextView textV;
    public programmingViewHolder(View itemView) {
        super(itemView);
        img =  itemView.findViewById(R.id.img);
        textV =  itemView.findViewById(R.id.textt);
    }
}

Answer 13

recyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));

recyclerView.setAdapter(adapter);

Answer 14

您可以在代码或布局 xml 文件中更改方向。

在xml文件中

在您的布局 xml 文件中，将 orientation 设置为 horizontal 并将 layoutManager 设置为 LinearLayoutManager、GridLayoutManager、StaggeredGridLayoutManager。根据您的要求选择。

<androidx.recyclerview.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />

在代码中

如果您想以编程方式更改方向，请将 layoutManager 设置为水平方向。

recyclerView.layoutManager = LinearLayoutManager(context, RecyclerView.HORIZONTAL, false)

Answer 15

只需在 XML

上的 RecyclerView 中添加这些属性

android:orientation="horizontal" app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"

如何使用 RecyclerView 构建水平的 ListView

How to build a horizontal ListView with RecyclerView

android

android-layout

android-recyclerview