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：

 1 package com.cloud.recycleviewdemo;
 2 
 3 import android.support.annotation.NonNull;
 4 import android.support.v7.widget.RecyclerView;
 5 import android.view.LayoutInflater;
 6 import android.view.View;
 7 import android.view.ViewGroup;
 8 import android.widget.ImageView;
 9 import android.widget.TextView;
10 
11 import java.util.List;
12 
13 class RecycleViewAdapter extends RecyclerView.Adapter {
14 
15     private List mItems;
16 
17     RecycleViewAdapter(List items) {
18         mItems = items;
19     }
20 
21     @Override
22     public int getItemCount() {
23         return mItems.size();
24     }
25 
26     @Override
27     public void onBindViewHolder(@NonNull ItemHolder holder, int position) {
28         //设置Item图片
29         holder.image.setImageResource(mItems.get(position).getImageResId());
30         //设置Item文字
31         holder.title.setText(mItems.get(position).getTitle());
32     }
33 
34     @NonNull
35     @Override
36     public ItemHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
37         return new ItemHolder(LayoutInflater
38                 .from(parent.getContext()).inflate(R.layout.item, parent, false));
39     }
40 
41     class ItemHolder extends RecyclerView.ViewHolder {
42 
43         ImageView image;
44         TextView title;
45 
46         ItemHolder(View item) {
47             super(item);
48             image = item.findViewById(R.id.image_view);
49             title = item.findViewById(R.id.text_title);
50         }
51     }
52 }

Item类：

 1 package com.cloud.recycleviewdemo;
 2 
 3 class Item {
 4 
 5     private int mImageResId;
 6     private String mTitle;
 7 
 8     Item(int imageResId, String title) {
 9         mImageResId = imageResId;
10         mTitle = title;
11     }
12 
13     public int getImageResId() {
14         return mImageResId;
15     }
16 
17     public void setImageResId(int imageResId) {
18         mImageResId = imageResId;
19     }
20 
21     public String getTitle() {
22         return mTitle;
23     }
24 
25     public void setTitle(String title) {
26         mTitle = title;
27     }
28 }

MainActivity代码：

 1 package com.cloud.recycleviewdemo;
 2 
 3 import android.support.v7.app.AppCompatActivity;
 4 import android.os.Bundle;
 5 import android.support.v7.widget.DefaultItemAnimator;
 6 import android.support.v7.widget.LinearLayoutManager;
 7 import android.support.v7.widget.RecyclerView;
 8 
 9 import java.util.ArrayList;
10 import java.util.List;
11 
12 public class MainActivity extends AppCompatActivity {
13 
14     private RecyclerView mRecyclerView;
15     private LinearLayoutManager mLinearLayoutManager;
16     private RecycleViewAdapter mRecycleViewAdapter;
17 
18     private List mData;
19 
20     @Override
21     protected void onCreate(Bundle savedInstanceState) {
22         super.onCreate(savedInstanceState);
23         setContentView(R.layout.activity_main);
24 
25         bindViews();
26         initData();
27         //初始化线性布局管理器
28         mLinearLayoutManager = new LinearLayoutManager(this);
29         //设置布局管理器
30         mRecyclerView.setLayoutManager(mLinearLayoutManager);
31         mRecyclerView.setItemAnimator(new DefaultItemAnimator());
32         //初始化适配器
33         mRecycleViewAdapter = new RecycleViewAdapter(mData);
34         //设置适配器
35         mRecyclerView.setAdapter(mRecycleViewAdapter);
36     }
37 
38     private void bindViews() {
39         mRecyclerView = findViewById(R.id.recycle_view);
40     }
41 
42     private void initData() {
43         mData = new ArrayList<>();
44         mData.add(new Item(R.drawable.witcher, "The Witcher 3: Wild Hunt"));
45         mData.add(new Item(R.drawable.recore, "Recore"));
46         mData.add(new Item(R.drawable.origins, "Assassin's Creed Origins"));
47         mData.add(new Item(R.drawable.hunter, "theHunter: Call of the Wild"));
48     }
49 }

Item布局：

 1 xml version="1.0" encoding="utf-8"?>
 2 <android.support.constraint.ConstraintLayout
 3     xmlns:android="http://schemas.android.com/apk/res/android"
 4     xmlns:app="http://schemas.android.com/apk/res-auto"
 5     xmlns:tools="http://schemas.android.com/tools"
 6     android:orientation="vertical"
 7     android:layout_width="match_parent"
 8     android:layout_height="wrap_content"
 9     android:layout_margin="4dp"
10     android:elevation="2dp"
11     android:background="@drawable/background_item">
12 
13     <ImageView
14         android:id="@+id/image_view"
15         android:contentDescription="@null"
16         android:layout_width="0dp"
17         android:layout_height="235dp"
18         android:layout_margin="6dp"
19         tools:src="@drawable/witcher"
20         app:layout_constraintTop_toTopOf="parent"
21         app:layout_constraintStart_toStartOf="parent"
22         app:layout_constraintEnd_toEndOf="parent" />
23 
24     <TextView
25         android:id="@+id/text_title"
26         android:layout_width="wrap_content"
27         android:layout_height="wrap_content"
28         android:textSize="18sp"
29         android:textColor="#000000"
30         android:layout_margin="6dp"
31         android:paddingBottom="4dp"
32         app:layout_constraintTop_toBottomOf="@+id/image_view"
33         app:layout_constraintStart_toStartOf="parent"
34         app:layout_constraintBottom_toBottomOf="parent"
35         tools:text="The Witcher 3: Wild Hunt" />
36 
37 android.support.constraint.ConstraintLayout>

MainActivity布局：

 1 xml version="1.0" encoding="utf-8"?>
 2 <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:app="http://schemas.android.com/apk/res-auto"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:layout_width="match_parent"
 6     android:layout_height="match_parent"
 7     tools:context=".MainActivity">
 8 
 9     <android.support.v7.widget.Toolbar
10         android:id="@+id/toolbar"
11         android:layout_width="match_parent"
12         android:layout_height="48dp"
13         android:background="@color/colorPrimary"
14         android:elevation="5dp"
15         app:layout_constraintEnd_toEndOf="parent"
16         app:layout_constraintStart_toStartOf="parent"
17         app:layout_constraintTop_toTopOf="parent">
18 
19         <ImageView
20             android:contentDescription="@null"
21             android:layout_width="36dp"
22             android:layout_height="36dp"
23             android:src="@drawable/icon" />
24 
25         <TextView
26             android:layout_width="wrap_content"
27             android:layout_height="wrap_content"
28             android:layout_gravity="center"
29             android:text="@string/app_name"
30             android:textColor="#FFFFFF"
31             android:textSize="18sp" />
32 
33     android.support.v7.widget.Toolbar>
34 
35     <android.support.v7.widget.RecyclerView
36         android:id="@+id/recycle_view"
37         android:layout_width="0dp"
38         android:layout_height="0dp"
39         app:layout_constraintBottom_toBottomOf="parent"
40         app:layout_constraintEnd_toEndOf="parent"
41         app:layout_constraintStart_toStartOf="parent"
42         app:layout_constraintTop_toBottomOf="@+id/toolbar"
43         app:layout_constraintVertical_bias="1.0">
44 
45     android.support.v7.widget.RecyclerView>
46 
47 android.support.constraint.ConstraintLayout>