RecyclerView（一）：基本使用

关于RecyclerView，我想大家都不陌生了，其基本使用就直接上流程步骤了。
第一步：添加依赖；

compile 'com.android.support:recyclerview-v7:25.1.1'

第二步：创建对象并初始化；

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.aaaaa.snaphelperdemo.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </android.support.v7.widget.RecyclerView>
</RelativeLayout>

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

        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recyclerview);
        // 设置布局管理器
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        linearLayoutManager.setOrientation(LinearLayout.VERTICAL);
        recyclerView.setLayoutManager(linearLayoutManager);
        // 设置item添加、移除动画
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        // 添加分割线
        recyclerView.addItemDecoration(new DividerItemDecoration(
                getApplicationContext(), DividerItemDecoration.VERTICAL));
        // 添加adapter
    }

第三步：写adapter；
A 布局文件recyclerview_item.xml

<?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="match_parent">

    <TextView
        android:id="@+id/recyclerview_item_text"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:layout_gravity="center"/>

</LinearLayout>

B Adapter代码

package com.example.aaaaa.recyclerviewtest;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

/**
 * Created by 49375 on 2019/3/19.
 */

public class RecyclerViewTestAdapter extends RecyclerView.Adapter<RecyclerViewTestAdapter.MyHolder> {
    @Override
    public RecyclerViewTestAdapter.MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_item, null);
        MyHolder myHolder = new MyHolder(view);
        return myHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerViewTestAdapter.MyHolder holder, int position) {
        holder.textView.setText(String.valueOf(position));
    }

    @Override
    public int getItemCount() {
        return 20;
    }

    // ViewHolder用来初始化控件
    public class MyHolder extends RecyclerView.ViewHolder {
        TextView textView;
        public MyHolder(View itemView) {
            super(itemView);
            textView = (TextView)itemView.findViewById(R.id.recyclerview_item_text);
        }
    }
}

C onCreate中recyclerView设置adapter

 // 添加adapter
        RecyclerView.Adapter adapter = new RecyclerViewTestAdapter();
        recyclerView.setAdapter(adapter);

以上，就是recyclerView的基本使用步骤，后续将会对RecyclerView实现侧滑删除、snaphelper实现view Pager+fragment左右翻页的功能等做记录。