Android RecycleView 自定义Item的使用

自定义布局的RecycleView需要自己实现Adapter，ViewHolder和布局；

自定义Adapter继承RecycleView.Adapter，重写getItemCount()，onBindViewHolder()和onCreateViewHolder()；

自定义ViewHolder继承于RecycleView.ViewHolder；

getItemCount()返回RecycleView中Item的个数，onBindViewHolder()主要实现数据和布局的绑定，onCreateViewHolder()加载布局；

效果：

适配器代码：

 package com.cloud.recycleviewdemo;

 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.ImageView;
 import android.widget.TextView;

 import java.util.List;

 class RecycleViewAdapter extends RecyclerView.Adapter<RecycleViewAdapter.ItemHolder> {

     private List<Item> mItems;

     RecycleViewAdapter(List<Item> items) {
         mItems = items;
     }

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

     @Override
     public void onBindViewHolder(@NonNull ItemHolder holder, int position) {
         //设置Item图片
         holder.image.setImageResource(mItems.get(position).getImageResId());
         //设置Item文字
         holder.title.setText(mItems.get(position).getTitle());
     }

     @NonNull
     @Override
     public ItemHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         return new ItemHolder(LayoutInflater
                 .from(parent.getContext()).inflate(R.layout.item, parent, false));
     }

     class ItemHolder extends RecyclerView.ViewHolder {

         ImageView image;
         TextView title;

         ItemHolder(View item) {
             super(item);
             image = item.findViewById(R.id.image_view);
             title = item.findViewById(R.id.text_title);
         }
     }
 }

Item类：

 package com.cloud.recycleviewdemo;

 class Item {

     private int mImageResId;
     private String mTitle;

     Item(int imageResId, String title) {
         mImageResId = imageResId;
         mTitle = title;
     }

     public int getImageResId() {
         return mImageResId;
     }

     public void setImageResId(int imageResId) {
         mImageResId = imageResId;
     }

     public String getTitle() {
         return mTitle;
     }

     public void setTitle(String title) {
         mTitle = title;
     }
 }

MainActivity代码：

 package com.cloud.recycleviewdemo;

 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.support.v7.widget.DefaultItemAnimator;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;

 import java.util.ArrayList;
 import java.util.List;

 public class MainActivity extends AppCompatActivity {

     private RecyclerView mRecyclerView;
     private LinearLayoutManager mLinearLayoutManager;
     private RecycleViewAdapter mRecycleViewAdapter;

     private List<Item> mData;

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

         bindViews();
         initData();
         //初始化线性布局管理器
         mLinearLayoutManager = new LinearLayoutManager(this);
         //设置布局管理器
         mRecyclerView.setLayoutManager(mLinearLayoutManager);
         mRecyclerView.setItemAnimator(new DefaultItemAnimator());
         //初始化适配器
         mRecycleViewAdapter = new RecycleViewAdapter(mData);
         //设置适配器
         mRecyclerView.setAdapter(mRecycleViewAdapter);
     }

     private void bindViews() {
         mRecyclerView = findViewById(R.id.recycle_view);
     }

     private void initData() {
         mData = new ArrayList<>();
         mData.add(new Item(R.drawable.witcher, "The Witcher 3: Wild Hunt"));
         mData.add(new Item(R.drawable.recore, "Recore"));
         mData.add(new Item(R.drawable.origins, "Assassin's Creed Origins"));
         mData.add(new Item(R.drawable.hunter, "theHunter: Call of the Wild"));
     }
 }

Item布局：

 <?xml version="1.0" encoding="utf-8"?>
 <android.support.constraint.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:orientation="vertical"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:layout_margin="4dp"
     android:elevation="2dp"
     android:background="@drawable/background_item">

     <ImageView
         android:id="@+id/image_view"
         android:contentDescription="@null"
         android:layout_width="0dp"
         android:layout_height="235dp"
         android:layout_margin="6dp"
         tools:src="@drawable/witcher"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent" />

     <TextView
         android:id="@+id/text_title"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:textSize="18sp"
         android:textColor="#000000"
         android:layout_margin="6dp"
         android:paddingBottom="4dp"
         app:layout_constraintTop_toBottomOf="@+id/image_view"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"
         tools:text="The Witcher 3: Wild Hunt" />

 </android.support.constraint.ConstraintLayout>

MainActivity布局：

 <?xml version="1.0" encoding="utf-8"?>
 <android.support.constraint.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=".MainActivity">

     <android.support.v7.widget.Toolbar
         android:id="@+id/toolbar"
         android:layout_width="match_parent"
         android:layout_height="48dp"
         android:background="@color/colorPrimary"
         android:elevation="5dp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent">

         <ImageView
             android:contentDescription="@null"
             android:layout_width="36dp"
             android:layout_height="36dp"
             android:src="@drawable/icon" />

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_gravity="center"
             android:text="@string/app_name"
             android:textColor="#FFFFFF"
             android:textSize="18sp" />

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

     <android.support.v7.widget.RecyclerView
         android:id="@+id/recycle_view"
         android:layout_width="0dp"
         android:layout_height="0dp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/toolbar"
         app:layout_constraintVertical_bias="1.0">

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

 </android.support.constraint.ConstraintLayout>