Android开发学习之RecyclerView

1、在app/build.gradle中添加recyclerview依赖

1 implementation 'com.android.support:recyclerview-v7:28.0.0'

注意依赖版本号

2、布局文件activity_main.xml引入recycleview

1 <android.support.v7.widget.recyclerview
2         android:id="@+id/recycler_view"
3         android:layout_width="match_parent"
4         android:layout_height="match_parent"></android.support.v7.widget.recyclerview>

3、泛型类型fruit.java

 1 package com.example.lalala.recyclerviewdemo;
 2 
 3 public class fruit {
 4     private string name;
 5     private int imageid;
 6     public fruit(string name,int imageid){
 7         this.name = name;
 8         this.imageid = imageid;
 9     }
10 
11     public string getname() {
12         return name;
13     }
14 
15     public int getimageid() {
16         return imageid;
17     }
18 }

4、布局fruit_item.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="horizontal" android:layout_width="match_parent"
 4     android:layout_height="wrap_content">
 5     <imageview
 6         android:id="@+id/fruit_image"
 7         android:layout_width="wrap_content"
 8         android:layout_height="wrap_content" />
 9     <textview
10         android:id="@+id/fruit_name"
11         android:layout_width="wrap_content"
12         android:layout_height="wrap_content"
13         android:layout_gravity="center_vertical"
14         android:layout_marginleft="10dp"
15         />
16 </linearlayout>

5、适配器fruitadapter.java

 1 package com.example.lalala.recyclerviewdemo;
 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 public class fruitadapter extends recyclerview.adapter<fruitadapter.viewholder> {
14     //适配器保存的数据
15     private list<fruit> mfruitlist;
16     //view容器类，viewholder容纳view
17     static class viewholder extends recyclerview.viewholder{
18         imageview imageview;
19         textview textview;
20         public viewholder(view view){
21             super(view);
22             imageview = (imageview)view.findviewbyid(r.id.fruit_image);
23             textview = (textview)view.findviewbyid(r.id.fruit_name);
24         }
25     }
26     //构造函数初始化适配器
27     public fruitadapter(list<fruit> fruitlist){
28         mfruitlist = fruitlist;
29     }
30     //创建viewholder
31     @nonnull
32     @override
33     public viewholder oncreateviewholder(@nonnull viewgroup viewgroup, int i) {
34         view view = layoutinflater.from(viewgroup.getcontext()).inflate(r.layout.fruit_item,viewgroup,false);
35         viewholder viewholder = new viewholder(view);
36         return viewholder;
37     }
38     //绑定数据到viewholder
39     @override
40     public void onbindviewholder(@nonnull viewholder viewholder, int i) {
41         fruit fruit = mfruitlist.get(i);
42         viewholder.imageview.setimageresource(fruit.getimageid());
43         viewholder.textview.settext(fruit.getname());
44     }
45     //返回子项个数
46     @override
47     public int getitemcount() {
48         return mfruitlist.size();
49     }
50 }

6、配置并使用recyclerview

 1 package com.example.lalala.recyclerviewdemo;
 2 
 3 import android.support.v7.app.appcompatactivity;
 4 import android.os.bundle;
 5 import android.support.v7.widget.linearlayoutmanager;
 6 import android.support.v7.widget.recyclerview;
 7 
 8 import java.util.arraylist;
 9 import java.util.list;
10 
11 public class mainactivity extends appcompatactivity {
12 
13     private list<fruit> fruitlist = new arraylist<>();
14 
15     @override
16     protected void oncreate(bundle savedinstancestate) {
17         super.oncreate(savedinstancestate);
18         setcontentview(r.layout.activity_main);
19         initfruit();
20         //使用recyclerview
21         recyclerview recyclerview = (recyclerview)findviewbyid(r.id.recycler_view);
22         //布局管理器
23         linearlayoutmanager layoutmanager = new linearlayoutmanager(this);
24         recyclerview.setlayoutmanager(layoutmanager);
25         fruitadapter adapter = new fruitadapter(fruitlist);
26         recyclerview.setadapter(adapter);
27     }
28     private void initfruit(){
29         for(int i=0;i<8;i++){
30             fruit apple = new fruit("apple",r.mipmap.ic_launcher);
31             fruitlist.add(apple);
32             fruit pear = new fruit("pear",r.mipmap.ic_launcher);
33             fruitlist.add(pear);
34             fruit banana = new fruit("banana",r.mipmap.ic_launcher);
35             fruitlist.add(banana);
36         }
37     }
38 }

7、大功告成，运行截图