Android 如何使用RecyclerView构建水平ListView？

我需要在我的Android应用程序中实现一个水平列表视图。我做了一些研究，遇到了一些问题，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通过Recyclerview实现这一点

现在有没有更好的方法通过RecyclerView来实现这一点

对

使用

RecyclerView

时，需要指定负责在视图中布局每个项目的

LayoutManager

。允许您指定方向，就像正常的

线性布局一样

要使用
RecyclerView
创建水平列表，可以执行以下操作：

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

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

有一个名为RecyclerView的子类，您可以使用它来获得水平方向。
对于垂直方向
尝试构建水平ListView花费了太多时间。我从两个方面解决了这个问题

1.使用其适配器从PagerAdapter延伸的ViewPager

2.使用如上所述的RecyclerView。需要按照以下代码应用LayoutManager：

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

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

如果要将
RecyclerView
与
GridLayoutManager
一起使用，这是实现水平滚动的方法

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

随着RecyclerView库的发布，现在您可以轻松地将图像列表与文本绑定。您可以使用LinearLayoutManager指定列表的垂直或水平方向，如下所示


您可以下载完整的
如果您希望使用水平回收器视图作为查看页面，现在可以在支持库24.2.0版中添加的
LinearSnapHelper
的帮助下进行下载

首先将RecyclerView添加到您的活动/片段中

<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>

    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);

在您的活动/片段中

<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>

    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);

完整示例

垂直
RecyclerView
与水平视图之间唯一的真正区别在于如何设置
LinearLayoutManager
。下面是代码片段。下面是完整的示例

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

这个更完整的例子是仿照

更新渐变依赖项
确保应用程序
gradle.build
文件中存在以下依赖项：

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任何版本

创建活动布局
将
RecyclerView
添加到xml布局中

activity_main.xml

创建适配器
RecyclerView
需要一个适配器来用数据填充每行（水平项）中的视图。创建一个新的java文件

myRecycleServiceAdapter.java

注释


请注意，该活动实现了我们在适配器中定义的
项ClickListener
。这允许我们在
onItemClick
中处理项目单击事件

完成了
就这样。您现在应该能够运行您的项目，并获得类似于顶部图像的内容

笔记

当然，我的示例中的彩色视图可以替换为实际项目中的图像

试试这个：

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

只有在你有一个回收视图和一些碎片的情况下
 

 <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);
        }
    }

导入androidx.appcompat.app.appcompat活动；
导入android.content.Context；
导入android.content.ContextWrapper；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.os.AsyncTask；
导入android.os.Bundle；
导入android.os.Environment；
导入android.view.view；
导入android.widget.ImageView；
导入android.widget.Toast；
导入java.io.File；
导入java.io.FileInputStream；
导入java.io.FileNotFoundException；
导入java.io.FileOutputStream；
导入java.io.IOException；
导入java.io.InputStream；
导入java.net.HttpURLConnection；
公共类MainActivity扩展了AppCompatActivity
{
图像视图mImageView1；
位图；
字符串mSavedInfo；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
mImageView1=（ImageView）findviewbyd（R.id.image）；
}
公共位图getBitmapFromURL（字符串src）{
试一试{
java.net.URL=新的java.net.URL（src）；
HttpURLConnection connection=（HttpURLConnection）url.openConnection（）；
connection.setDoInput（true）；
connection.connect（）；
InputStream输入=连接。getInputStream（）；
位图myBitmap=BitmapFactory.decodeStream（输入）；
返回我的位图；
}捕获（IOE异常）{
e、 printStackTrace（）；
返回null；
}
}
公共无效按钮2（视图）{
新下载的ImageFromtherAD（）.execute（）；
}
私有类从RAD扩展异步任务下载图像{
@凌驾
受保护的字符串doInBackground（字符串…参数）{
位图=getBitmapFromURL（“https://cdn.pixabay.com/photo/2016/08/08/09/17/avatar-1577909_960_720.png");
返回null；
}
@凌驾
受保护的void onPostExecute（字符串s）{
super.onPostExecute（s）；
文件sdCardDirectory=Environment.getExternalStorageDirectory（）；
File image=新文件（sdCardDirectory，“test.png”）；
布尔成功=假；
FileOutputStream扩展流；
mSavedInfo=saveToInternalStorage（位图）；
如果（成功）{
Toast.makeText（getApplicationContext（），“成功保存图像”，Toast.LENGTH_LONG.show（）；
}否则{
Toast.makeText（getApplicationContext（），“图像保存期间出错”+mSav
<?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>

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);
    }
}

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();
    }
}

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

 <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);
        }
    }

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);

}

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));'

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);