RecyclerView刷新与加载更多

   序言:上一篇述说了android架构层，本篇主要学习RecyclerView刷新与加载，原理就是刷新使用的是SwipeRefireshLayout，而加载更多是采用RecyclerView的滚动监听(addOnScrollListener),

      1.第一步当然是先写布局啦

<?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="match_parent"   android:orientation="vertical"><android.support.v4.widget.SwipeRefreshLayout    android:id="@+id/srf_mains"    android:layout_width="wrap_content"    android:layout_height="wrap_content">    <android.support.v7.widget.RecyclerView        android:id="@+id/rv_ab"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:background="@android:color/holo_blue_bright"/></android.support.v4.widget.SwipeRefreshLayout></LinearLayout>

其中SwipeRefireshLayout是谷歌原生的刷新控件，所以现在好多软件都采用这种效果来刷新数据，RecyclerView是

ListView和GridView的更新迭代产品，虽然代码相对复杂点，没有setonImtemOnclickListener,只能在itemview设置或者设置回调，但却相对灵活，也很强大，能实现横向，纵向，瀑布流等效果。

2.业务逻辑

public class Main2Activity extends AppCompatActivity {    private List<String> list = new ArrayList<>();    MyViewAdapter myViewAdapter;    SwipeRefreshLayout srf_mains;    RecyclerView rv_ab;    @TargetApi(Build.VERSION_CODES.M)    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main2);        //初始化视图        initView();        //业务逻辑        initData();    }    private void initView() {        srf_mains = (SwipeRefreshLayout) findViewById(R.id.srf_mains);        rv_ab = (RecyclerView) findViewById(R.id.rv_ab);    }    private void initData() {        //给集合创建假数据        for (int i=0;i<20;i++){            list.add("第"+i+"条数据");        }        //设置recyclerview的样式，这里采用纵向线性样式        rv_ab.setLayoutManager(new LinearLayoutManager(this));        //创建适配器        myViewAdapter = new MyViewAdapter();        //设置设配器        rv_ab.setAdapter(myViewAdapter);        //SwipeRefreshLayout设置刷新监听，这里模拟集合数据清空，重新添加        srf_mains.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {            @Override            public void onRefresh() {                if (list.size()>0){                    list.clear();                    for (int i=0;i<20;i++){                        list.add("第"+i+"条数据");                    }                }                myViewAdapter.notifyDataSetChanged();                srf_mains.setRefreshing(false);                ToastUtils.show(Main2Activity.this,"刷新成功");            }        });         //recyclerview设置滚动监听，当到达最底部时分页加载数据，刷新适配器        rv_ab.addOnScrollListener(new RecyclerView.OnScrollListener() {            @Override            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {                super.onScrollStateChanged(recyclerView, newState);                if(newState == RecyclerView.SCROLL_STATE_IDLE){                    list.add(list.size()-1,"底部");                    myViewAdapter.notifyDataSetChanged();                }            }        });    }

3.最后粘上adapter的代码

private class MyViewAdapter extends RecyclerView.Adapter<MyViewAdapter.MyViewHolder> {    @Override    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        if (viewType==0){            return new MyViewHolder(LayoutInflater.from(Main2Activity.this).inflate(R.layout.item_view, parent, false));        }        return new MyViewHolder(LayoutInflater.from(Main2Activity.this).inflate(R.layout.item_views, parent, false));    }    @Override    public int getItemViewType(int position) {        if (position==list.size()-1){            return 1;        }        return 0;    }    @Override    public void onBindViewHolder(MyViewHolder holder, int position) {        if (position!=list.size()-1){            holder.tv_iteme.setText(list.get(position));        }    }    @Override    public int getItemCount() {        return list.size();    }    public class MyViewHolder extends RecyclerView.ViewHolder {        TextView tv_iteme;        public MyViewHolder(View itemView) {            super(itemView);            tv_iteme = (TextView) itemView.findViewById(R.id.tv_iteme);        }    }}

总结:我采用的是分类型的adapter，一部分是数据显示部分，底部是加载更多显示，通过对recyclerview的滚动监听，当滑动到底部来加载更多，也就是分页显示，刷新部分采用的是官方的控件。