如何在Android Studio中将ListView更改为RecyclerView？

我不知道如何使用RecyclerView替换ListView。有人能帮我吗？非常感谢。我在不同的在线平台上找到了很多资源，但我不知道如何更改代码。当我试图修改代码时，它不起作用

代码如下所示：

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getSimpleName();

    private ProgressDialog pDialog;
    private ListView lv;

    // URL to get contacts JSON
    private static String url = "https://api.androidhive.info/contacts/";

    ArrayList<HashMap<String, String>> contactList;

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

        contactList = new ArrayList<>();

        lv = (ListView) findViewById(R.id.list);

        new GetContacts().execute();
    }

    /**
     * Async task class to get json by making HTTP call
     */
    private class GetContacts extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // Showing progress dialog
            pDialog = new ProgressDialog(MainActivity.this);
            pDialog.setMessage("Please wait...");
            pDialog.setCancelable(false);
            pDialog.show();

        }

        @Override
        protected Void doInBackground(Void... arg0) {
            HttpHandler sh = new HttpHandler();

            // Making a request to url and getting response
            String jsonStr = sh.makeServiceCall(url);

            Log.e(TAG, "Response from url: " + jsonStr);

            if (jsonStr != null) {
                try {
                    JSONObject jsonObj = new JSONObject(jsonStr);

                    // Getting JSON Array node
                    JSONArray contacts = jsonObj.getJSONArray("contacts");

                    // looping through All Contacts
                    for (int i = 0; i < contacts.length(); i++) {
                        JSONObject c = contacts.getJSONObject(i);

                        String id = c.getString("id");
                        String name = c.getString("name");
                        String email = c.getString("email");
                        String address = c.getString("address");
                        String gender = c.getString("gender");

                        // Phone node is JSON Object
                        JSONObject phone = c.getJSONObject("phone");
                        String mobile = phone.getString("mobile");
                        String home = phone.getString("home");
                        String office = phone.getString("office");

                        // tmp hash map for single contact
                        HashMap<String, String> contact = new HashMap<>();

                        // adding each child node to HashMap key => value
                        contact.put("id", id);
                        contact.put("name", name);
                        contact.put("email", email);
                        contact.put("mobile", mobile);

                        // adding contact to contact list
                        contactList.add(contact);
                    }
                } catch (final JSONException e) {
                    Log.e(TAG, "Json parsing error: " + e.getMessage());
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(getApplicationContext(),
                                    "Json parsing error: " + e.getMessage(),
                                    Toast.LENGTH_LONG)
                                    .show();
                        }
                    });

                }
            } else {
                Log.e(TAG, "Couldn't get json from server.");
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(),
                                "Couldn't get json from server. Check LogCat for possible errors!",
                                Toast.LENGTH_LONG)
                                .show();
                    }
                });

            }

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            // Dismiss the progress dialog
            if (pDialog.isShowing())
                pDialog.dismiss();

            ListAdapter adapter = new SimpleAdapter(
                    MainActivity.this, contactList,
                    R.layout.list_item, new String[]{"name", "email",
                    "mobile"}, new int[]{R.id.name,
                    R.id.email, R.id.mobile});

            lv.setAdapter(adapter);
        }

    }
}

activity_main.xml

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="hk.edu.ouhk.android.jsonparsing.MainActivity">

    <ListView
        android:id="@+id/list"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dip">

    <TextView
        android:id="@+id/name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="2dip"
        android:paddingTop="6dip"
        android:textColor="@color/colorPrimaryDark"
        android:textSize="16sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/email"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="2dip"
        android:textColor="#5d5d5d" />

    <TextView
        android:id="@+id/mobile"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#686868"
        android:textStyle="bold" />

</LinearLayout>

基本上，您需要使用ViewHolder模式创建RecycleServiceAdapter，只需将ListView替换为RecyclerView即可，因为从url获取数据似乎没有问题，并且您已经成功地从数据创建了Arraylist

现在要采取的步骤 1.将recyclerview添加到活动的xml中 2.在recyclerview项中创建显示数据的布局 3.然后，您需要制作一个适配器，用于获取您提供的数据并将其绑定到该适配器 回收者视图 4.然后将适配器添加到回收器视图中

我附上简单的回收视图，这是我刚才为我做的。这很简单，不言自明。否则你可以评论，我会详细解释的

Main Activity
public class MainActivity extends AppCompatActivity {
ArrayList<String> moviesList;
RecyclerView recyclerView;
RecyclerAdapter recyclerAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    moviesList=new ArrayList<>();
    recyclerView=findViewById(R.id.recyclerView);
    recyclerAdapter=new RecyclerAdapter(moviesList);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(recyclerAdapter);
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil"); }
 }



RecyclerAdapter in this we are creating custom viewholder for us
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> 
  {
public RecyclerAdapter(ArrayList<String> moviesList) {
    this.moviesList = moviesList;
}

ArrayList<String> moviesList;
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext());
    View view=layoutInflater.inflate(R.layout.row_layout,parent,false);
    ViewHolder viewHolder= new ViewHolder(view);
    return viewHolder;
}

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
holder.rowTextView.setText(String.valueOf(position));
holder.textView.setText(moviesList.get(position));
}

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

class ViewHolder extends RecyclerView.ViewHolder {
    ImageView imageView;
    TextView textView,rowTextView;
    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        imageView=itemView.findViewById(R.id.imageView);
        textView=itemView.findViewById(R.id.textView);
        rowTextView=itemView.findViewById(R.id.rowTextView);
    }
  }
 }

 This is layout for the item which I want to show in recycler view
  <?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<ImageView
    android:id="@+id/imageView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="22dp"
    android:layout_marginTop="16dp"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:srcCompat="@drawable/ic_launcher_background" />

<TextView
    android:id="@+id/textView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="32dp"
    android:layout_marginTop="22dp"
    android:text="TextView"
    android:textAppearance="@style/TextAppearance.AppCompat.Large"
    app:layout_constraintStart_toEndOf="@+id/imageView"
    app:layout_constraintTop_toTopOf="parent" />

<TextView
    android:id="@+id/rowTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="33dp"
    android:layout_marginTop="16dp"
    android:text="TextView"
    app:layout_constraintStart_toEndOf="@+id/imageView"
    app:layout_constraintTop_toBottomOf="@+id/textView" />
   </androidx.constraintlayout.widget.ConstraintLayout>

主要活动
公共类MainActivity扩展了AppCompatActivity{
ArrayList电影列表；
回收视图回收视图；
回收器适配器回收器适配器；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
moviesList=newarraylist（）；
recyclerView=findViewById（R.id.recyclerView）；
recyclerAdapter=新的recyclerAdapter（电影列表）；
recyclerView.setLayoutManager（新的LinearLayoutManager（本））；
recyclerView.setAdapter（recyclerAdapter）；
电影列表。添加（“Kapil”）；
电影列表。添加（“Kapil”）；
电影列表。添加（“Kapil”）；
电影列表。添加（“Kapil”）；
电影列表。添加（“Kapil”）；
电影列表。添加（“Kapil”）；
moviesList.add（“Kapil”）；}
}
RecyclerAdapter在这里，我们正在为我们创建自定义的viewholder
公共类RecyclerAdapter扩展了RecyclerView.Adapter
{
公共回收器适配器（ArrayList电影列表）{
this.moviesList=moviesList；
}
ArrayList电影列表；
@非空
@凌驾
public ViewHolder onCreateViewHolder（@NonNull ViewGroup parent，int viewType）{
LayoutInflater LayoutInflater=LayoutInflater.from（parent.getContext（））；
视图=布局更平坦。充气（R.layout.row\u布局，父级，false）；
ViewHolder ViewHolder=新的ViewHolder（视图）；
返回视图持有者；
}
@凌驾
public void onBindViewHolder（@NonNull ViewHolder，int位置）{
holder.rowTextView.setText（String.valueOf（position））；
holder.textView.setText（moviesList.get（position））；
}
@凌驾
public int getItemCount（）{
返回moviesList.size（）；
}
类ViewHolder扩展了RecyclerView.ViewHolder{
图像视图图像视图；
文本视图文本视图，行文本视图；
公共视图持有者（@NonNull View itemView）{
超级（项目视图）；
imageView=itemView.findViewById（R.id.imageView）；
textView=itemView.findViewById（R.id.textView）；
rowTextView=itemView.findViewById（R.id.rowTextView）；
}
}
}
这是我要在“回收器”视图中显示的项目的布局

---

只需将数组列表传递给它。就像我做的那样

但是我不知道如何写ViewHolder。你能给我一些提示吗？谢谢。这很简单，只要读几篇像这样的初学者的帖子就可以了。你说它不起作用是什么意思？你犯了什么错误？

Main Activity
public class MainActivity extends AppCompatActivity {
ArrayList<String> moviesList;
RecyclerView recyclerView;
RecyclerAdapter recyclerAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    moviesList=new ArrayList<>();
    recyclerView=findViewById(R.id.recyclerView);
    recyclerAdapter=new RecyclerAdapter(moviesList);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(recyclerAdapter);
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil");
    moviesList.add("Kapil"); }
 }



RecyclerAdapter in this we are creating custom viewholder for us
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> 
  {
public RecyclerAdapter(ArrayList<String> moviesList) {
    this.moviesList = moviesList;
}

ArrayList<String> moviesList;
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext());
    View view=layoutInflater.inflate(R.layout.row_layout,parent,false);
    ViewHolder viewHolder= new ViewHolder(view);
    return viewHolder;
}

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
holder.rowTextView.setText(String.valueOf(position));
holder.textView.setText(moviesList.get(position));
}

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

class ViewHolder extends RecyclerView.ViewHolder {
    ImageView imageView;
    TextView textView,rowTextView;
    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        imageView=itemView.findViewById(R.id.imageView);
        textView=itemView.findViewById(R.id.textView);
        rowTextView=itemView.findViewById(R.id.rowTextView);
    }
  }
 }

 This is layout for the item which I want to show in recycler view
  <?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<ImageView
    android:id="@+id/imageView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="22dp"
    android:layout_marginTop="16dp"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:srcCompat="@drawable/ic_launcher_background" />

<TextView
    android:id="@+id/textView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="32dp"
    android:layout_marginTop="22dp"
    android:text="TextView"
    android:textAppearance="@style/TextAppearance.AppCompat.Large"
    app:layout_constraintStart_toEndOf="@+id/imageView"
    app:layout_constraintTop_toTopOf="parent" />

<TextView
    android:id="@+id/rowTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="33dp"
    android:layout_marginTop="16dp"
    android:text="TextView"
    app:layout_constraintStart_toEndOf="@+id/imageView"
    app:layout_constraintTop_toBottomOf="@+id/textView" />
   </androidx.constraintlayout.widget.ConstraintLayout>