Android studio3.5.3没有了不是使用的android.support.v7.widget.RecyclerView这种形式的,而是使用androidx.recyclerview.widget.RecyclerView。
引入包的方法
1.File----Project Structuer----Dependencies----app----"+"----Library Dependency
2.搜索recyclerview引入最上面的androidx
3.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=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
></androidx.recyclerview.widget.RecyclerView>
</androidx.constraintlayout.widget.ConstraintLayout>
item_dome.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="50dp">
<TextView
android:id="@+id/text_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="测试"
android:layout_marginRight="1dp"
android:layout_marginLeft="1dp"
android:layout_marginTop="1dp"
android:layout_marginBottom="1dp"
android:textColor="@android:color/holo_red_dark"
android:background="@android:color/holo_blue_dark" />
</LinearLayout>
MainActivity.java
package com.ldw.recyclerview;
import android.content.Context;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
/**
* author: ldw
* created on: 2020/3/8 0:51
* description:
*/
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;//声明RecyclerView
private RecycleAdapterDome adapterDome;//声明适配器
private Context context;
private List<String> list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = this;
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
list = new ArrayList<>();
for (int i=0;i<10;i++){
list.add("这是第"+i+"个测试");
}
//
adapterDome = new RecycleAdapterDome(context,list);
/*
与ListView效果对应的可以通过LinearLayoutManager来设置
与GridView效果对应的可以通过GridLayoutManager来设置
与瀑布流对应的可以通过StaggeredGridLayoutManager来设置
*/
//LinearLayoutManager manager = new LinearLayoutManager(context,LinearLayoutManager.VERTICAL,false);
LinearLayoutManager manager = new LinearLayoutManager(context);
manager.setOrientation(LinearLayoutManager.VERTICAL);
//RecyclerView.LayoutManager manager = new LinearLayoutManager(context,LinearLayoutManager.VERTICAL,false);
//GridLayoutManager manager1 = new GridLayoutManager(context,2);
//manager1.setOrientation(GridLayoutManager.VERTICAL);
//StaggeredGridLayoutManager manager2 = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(manager);
recyclerView.setAdapter(adapterDome);
}
}
RecycleAdapterDome.java
package com.ldw.recyclerview;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
/**
* author: ldw
* created on: 2020/3/8 0:54
* description:
*/
public class RecycleAdapterDome extends RecyclerView.Adapter<RecycleAdapterDome.MyViewHolder>{
private Context context;
private List<String> list;
private View inflater;
//构造方法,传入数据
public RecycleAdapterDome(Context context, List<String> list){
this.context = context;
this.list = list;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//创建ViewHolder,返回每一项的布局
inflater = LayoutInflater.from(context).inflate(R.layout.item_dome,parent,false);
MyViewHolder myViewHolder = new MyViewHolder(inflater);
return myViewHolder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
//将数据和控件绑定
holder.textView.setText(list.get(position));
}
@Override
public int getItemCount() {
//返回Item总条数
return list.size();
}
//内部类,绑定控件
class MyViewHolder extends RecyclerView.ViewHolder{
TextView textView;
public MyViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.text_view);
}
}
}
效果如下:
第一步:
在布局中使用:
activity_main.xml
<android.support.v7.widget.RecyclerView
android:id="@+id/recycleview"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
下面要编写需要展示的item的样式,为了简单我们就显示一个TextView,别的内容大家可以自己定制:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="70dp"
android:background="#ff00ff"
android:layout_margin="2dp"
android:orientation="vertical">
<TextView
android:id="@+id/recycle_tv"
android:textSize="20dp"
android:gravity="center"
android:layout_width="72dp"
android:layout_height="match_parent" />
</LinearLayout>
Adapter的编写:
package com.ldw.a02recycleview;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
/**
* Created by guwei on 16-7-28.
*/
public class MyAdapter extends RecyclerView.Adapter<MyViewHolder>{
private LayoutInflater inflater;
private Context mContext;
private List<String> mDatas;
//创建构造参数
public MyAdapter(Context context , List<String> datas){
this.mContext = context;
this.mDatas = datas;
inflater = LayoutInflater.from(context);
}
//创建ViewHolder
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.recycleview_item , parent , false);
MyViewHolder viewHolder = new MyViewHolder(view);
return viewHolder;
}
//绑定ViewHolder
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
//为textview 赋值
holder.tv.setText(mDatas.get(position));
}
@Override
public int getItemCount() {
//Log.i("TAG", "mDatas "+mDatas);
return mDatas.size();
}
//新增item
public void addData(int pos){
mDatas.add("新增");
notifyItemInserted(pos);
}
//移除item
public void deleateData(int pos){
mDatas.remove(pos);
notifyItemRemoved(pos);
}
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView tv;
public MyViewHolder(View itemView) {
super(itemView);
tv = (TextView) itemView.findViewById(R.id.recycle_tv);
tv.setTextSize(20);
}
}
Adapter的编写主要是要继承自 RecyclerView.Adapter<holder>
原来继承BaseAdapter的时候还是建议使用ViewHolder的方法的。现在已经直接集成在RecyclerView.Adapter<holder>中了强制使用(这也是为你好!因为这样更省资源,不需要每次都使用find方法。这个不是本次重点)。
然后重写三个方法:
- onCreateViewHolder() //创建ViewHolder 该方法下指定我们自己定义的item 并绑定
- onBindViewHolder() //绑定ViewHolder 该方法为绑定的自定义的item中的组件进行设置(比如我们例子中的TextView , 使用set方法设置显示的内容)
- getItemCount() //返回数据的大小
MainActivity.java :
package com.ldw.a02recycleview;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
public String TAG = "RECYCLE";
private RecyclerView mRecycleView;
private List<String> mData;
private MyAdapter myAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initdata();
initview();
toolbar();
}
private void initdata() {
mData = new ArrayList<String>();
for (int i = 0; i < 43; i++) {
mData.add("item" + i);
Log.i(TAG, "initdata: item" + i);
}
}
private void initview() {
mRecycleView = (RecyclerView) findViewById(R.id.recycleview);
myAdapter = new MyAdapter(this, mData);
mRecycleView.setAdapter(myAdapter);//设置适配器
//设置布局管理器 , 将布局设置成纵向
LinearLayoutManager linerLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
mRecycleView.setLayoutManager(linerLayoutManager);
//设置分隔线
//mRecycleView.addItemDecoration(new DividerItemDecoration(this , DividerItemDecoration.VERTICAL_LIST));
//设置增加或删除条目动画
mRecycleView.setItemAnimator(new DefaultItemAnimator());
}
private void toolbar() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
myAdapter.addData(1);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
switch (id) {
case R.id.action_gridview:
/**
* GridLayoutManager(xx1 , xx2);
* 参数1: content
* 参数2: 列数
* **/
mRecycleView.setLayoutManager(new GridLayoutManager(this, 3));
break;
case R.id.action_listview:
/**
* 默认样式
*
* 垂直列表
* **/
mRecycleView.setLayoutManager(new LinearLayoutManager(this));
break;
/**
*水平显示
*
* 参数1:列数
* 参数2:水平显示
* **/
case R.id.action_settings:
mRecycleView.setLayoutManager(new StaggeredGridLayoutManager(5,
StaggeredGridLayoutManager.HORIZONTAL));
break;
}
return super.onOptionsItemSelected(item);
}
}
为RecyclerView的item添加监听事件。
RecyclerView本身没有为item设置监听事件,想要使用onclick或者onLongclick事件需要自己定义(这是最坑爹的),然后暴露方法供调用
实现RecyclerView 的item 的监听事件需要以下几步:
1、在Adapter方法中添加监听接口onItemClickListener和onItemLongClickListener;
2、暴露接口的set方法;
3、在onBindviewHolder方法中编写onItemClickListener和onItemLongClickListener的监听
4、调用该方法
在Adapter方法中添加监听接口onItemClickListener和onItemLongClickListener
public interface OnItemClieckLinster{
void onItemClickListener(View view , int pos);
void onItemLongClickListener(View view , int pos);
}
暴漏方法:
private OnItemClieckLinster onItemClieckLinster;
public void setOnItemClieckLinster(OnItemClieckLinster listener){
this.onItemClieckLinster = listener;
}
实现监听,重写onBindViewHolder方法
//绑定ViewHolder
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
//为textview 赋值
holder.tv.setText(mDatas.get(position));
if(onItemClieckLinster != null){
//onitemclicklistener
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
onItemClieckLinster.onItemClickListener(holder.itemView , position);
}
});
//onitemlongclicklistener
holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
onItemClieckLinster.onItemLongClickListener(holder.itemView , position);
return false;
}
});
}
}
调用监听
myAdapter.setOnItemClieckLinster(new MyAdapter.OnItemClieckLinster() {
@Override
public void onItemClickListener(View view, int pos) {
Toast.makeText(MainActivity.this, "click" + pos , Toast.LENGTH_SHORT).show();
}
@Override
public void onItemLongClickListener(View view, int pos) {
Toast.makeText(MainActivity.this, "long click" + pos , Toast.LENGTH_SHORT).show();
}
});