如何更新 RecyclerView 适配器数据？

此示例演示了如何更新 RecyclerView 适配器数据。

步骤 1 - 在 Android Studio 中创建一个新项目，转到文件 ⇒ 新建项目，并填写所有必需的详细信息以创建新项目。

步骤 2 - 将以下代码添加到 res/layout/activity_main.xml 中。

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   android:orientation = "vertical"
   android:layout_width = "match_parent"
   android:gravity = "center"
   android:layout_height = "wrap_content">
   <android.support.v7.widget.RecyclerView
      android:id = "@+id/recycler_view"
      android:layout_width = "match_parent"
      android:layout_height = "400dp"
      android:scrollbars = "vertical" />
   <TextView
      android:id = "@+id/text"
      android:textSize = "30sp"
      android:text = "Update"
      android:layout_width = "wrap_content"
      android:layout_height = "wrap_content" />
</LinearLayout>

在上面的代码中，我们使用了 RecyclerView。

步骤 3 - 将以下代码添加到 src/MainActivity.java 中。

<?xml version = "1.0" encoding = "utf-8"?>
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.content.pm.ShortcutInfoCompat;
import android.support.v4.content.pm.ShortcutManagerCompat;
import android.support.v4.graphics.drawable.IconCompat;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;

public class MainActivity extends Activity {
   private RecyclerView recyclerView;
   private customAdapter mAdapter;
   TextView text;
   ArrayList<String> list = new ArrayList<>();
   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
      RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
      recyclerView.setLayoutManager(mLayoutManager);
      recyclerView.setItemAnimator(new DefaultItemAnimator());
      mAdapter = new customAdapter(this,list);
      recyclerView.setAdapter(mAdapter);
      recyclerView.addItemDecoration(new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL));
      list.add("sairamm");
      list.add("Krishna");
      list.add("prasad");
      text = findViewById(R.id.text);
      text.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            list.add("Mammahe");
            mAdapter.notifyDataSetChanged();
         }
      });
   }
}

步骤 4 - 将以下代码添加到 src/customAdapter.java 中。

<?xml version = "1.0" encoding = "utf-8"?>
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;
import android.widget.TextView;
import java.util.ArrayList;

public class customAdapter extends RecyclerView.Adapter<customAdapter.MyViewHolder> {
   Context context;
   ArrayList<String> list;
   public class MyViewHolder extends RecyclerView.ViewHolder {
      public TextView title;
      public MyViewHolder(View view) {
         super(view);
         title = (TextView) view.findViewById(R.id.title);
      }
   }
   public customAdapter(Context context, ArrayList<String> list) {
      this.context = context;
      this.list = list;
   }
   @NonNull
   @Override
   public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
      View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.list_row, viewGroup, false);
      return new MyViewHolder(itemView);
   }
   @Override
   public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, int i) {
      myViewHolder.title.setText(list.get(i));
   }
   @Override
   public int getItemCount() {
      return list.size();
   }
}

步骤 5 - 将以下代码添加到 res/layout/list_row.xml 中。

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   android:orientation = "vertical" android:layout_width = "match_parent"
   android:layout_height = "wrap_content">
   <TextView
      android:id = "@+id/title"
      android:layout_width = "wrap_content"
      android:textSize = "30sp"
      android:layout_marginLeft = "10dp"
      android:layout_height = "wrap_content" />
</LinearLayout>

让我们尝试运行您的应用程序。我假设您已将您的实际 Android 移动设备连接到您的计算机。要从 Android Studio 运行应用程序，请打开项目中的一个 Activity 文件，然后单击工具栏中的运行图标。选择您的移动设备作为选项，然后检查您的移动设备，它将显示您的默认屏幕 -