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，发现如何在Android中制作水平ListView？和水平ListView在Android中？但是，这些问题是在Recyclerview发布之前提出的。现在有没有更好的方法可以通过Recyclerview来实现呢？

现在有没有更好的方法现在可以使用Recyclerview来实现呢？

是。

使用时RecyclerView，您需要指定一个LayoutManager负责布置视图中每个项目的布局。在LinearLayoutManager允许您指定的方向，就像一个正常的LinearLayout会。

要使用创建横向列表RecyclerView，您可以执行以下操作：

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

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

 <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" />

完整的例子

垂直RecyclerView和水平的唯一真正的区别是您如何设置LinearLayoutManager。这是代码片段。完整的示例如下。

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

这个更完整的例子是根据我的垂直RecyclerView答案建模的。

更新Gradle依赖项

确保以下依赖项位于您的应用程序gradle.build文件中：

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

您可以更新的版本号无论是最新的。

创建活动布局

将添加RecyclerView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

我们中的每个项目都会在上方有RecyclerView一个颜色。创建一个新的布局资源文件。ViewTextView

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

将RecyclerView需要一个适配器来填充你的数据在每一行（水平项目）的意见。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);
    }
}

笔记

• 尽管并非绝对必要，但我包括了用于侦听项目单击事件的功能。这在过去是可用的ListViews，是常见的需求。如果不需要，可以删除此代码。

在活动中初始化RecyclerView

将以下代码添加到您的主要活动中。

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();
    }
}

笔记

• 请注意，该活动实现了ItemClickListener我们在适配器中定义的。这使我们能够处理中的项目单击事件onItemClick。

已完成

而已。您应该现在就可以运行您的项目，并获得类似于顶部的图像。

笔记

• 在我的示例中，彩色视图当然可以用真实项目中的图像替换。
• 立式RecyclerView示例

如果你想使用RecyclerView同GridLayoutManager，这是实现横向滚动的方式。

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

尝试构建水平ListView会花费太多时间。我已经通过两种方式解决了它。

1.通过使用其适配器从PagerAdapter扩展的ViewPager。

2.通过如上所述使用RecyclerView。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);

如果您希望使用卧式回收机视图作为ViewPager，那么现在可以LinearSnapHelper在支持库版本24.2.0中添加它。

首先将RecyclerView添加到您的活动/片段

<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>

在我来说，我已经使用了一个CardView内部的RecyclerView

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>

在您的活动/片段中

    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);

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来指定列表的方向，如下所示，可以垂直或水平。

您可以从这篇文章下载完整的工作演示

 <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>

    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);
        }
    }

有一个名为Horizo​​ntalGridView的RecyclerView子类，您可以使用它具有水平方向。 VerticalGridView用于垂直方向

适用于水平和垂直。

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);

}

水平动态中的回收者视图。

回收者视图实施

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));'

回收者视图的适配器类，其中有一个视图保持器，用于保存该回收者的视图

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);
    }
}

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

recyclerView.setAdapter(adapter);

尝试这个：

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

仅当您获得带有某些碎片的回收站视图时。