RecyclerView基本使用

前言

因为工作期间，一直用的旧的View，还没用过新出的这些ViewO(∩_∩)O~

一、基本用法

这里直接添上了头部以及删除添加
1. build.gradle

 compile 'com.android.support:recyclerview-v7:25.2.0'

2. 布局

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

3. 在activity中的使用

 List<String> list = new ArrayList<>();
    MyAdapter myAdapter;

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

        RecyclerView recycler = (RecyclerView) findViewById(R.id.recycler);
        GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 2);//设置样式，也可以用LinearLayoutManager线性布局或者StaggeredGridLayoutManager瀑布流布局
        gridLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);//设置方向
        recycler.setLayoutManager(gridLayoutManager);

        //这是为了添加头部，是第一条的话（即头部header），就跨两列，不是第一条就还是一列
        gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
            @Override
            public int getSpanSize(int position) {
                if (position == 0) return 2;
                else return 1;
            }
        });
        recycler.setHasFixedSize(true); //如果item大小是一致的，则可以设置，这样子可以改善性能
        recycler.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL));//设置分割线，默认是android自带的listDivider
        recycler.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));//设置分割线，默认是android自带的listDivider
        recycler.setItemAnimator(new DefaultItemAnimator()); //设置ITEM增加删除的动画
        for (int i = 0; i < 9; i++) {
            list.add(i + "--");
        }
        View inflate = LayoutInflater.from(this).inflate(R.layout.section, null); //header
        myAdapter = new MyAdapter(inflate, list);
        recycler.setAdapter(myAdapter);
    }


    public void addItem(View view) {
        list.add(0, "添加");
        myAdapter.notifyItemInserted(1);
    }

    public void removeItem(View view) {
        list.remove(0);
        myAdapter.notifyItemRemoved(1);
    }

4. adapter

   class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
        private View header;
        private List<String> datas;
        public static final int ITEM_VIEW_TYPE_HEADER = 0;
        public static final int ITEM_VIEW_TYPE_ITEM = 1;


        public MyAdapter(View header, List<String> datas) {
            if (header == null) {
                throw new IllegalArgumentException("header is null");
            }
            this.header = header;
            this.datas = datas;
        }

        boolean isHeader(int position) {
            return position == 0;
        }

        @Override
        public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            if (viewType == ITEM_VIEW_TYPE_HEADER) {
                return new ViewHolder(header);
            }
            View view = LayoutInflater.from(parent.getContext()).inflate(android.R.layout.simple_list_item_1, parent, false);
            ViewHolder viewHolder = new ViewHolder(view);
            return viewHolder;
        }

        @Override
        public int getItemViewType(int position) {
            return isHeader(position) ? ITEM_VIEW_TYPE_HEADER : ITEM_VIEW_TYPE_ITEM;
        }

        @Override
        public void onBindViewHolder(ViewHolder holder, int position) {
            if (isHeader(position)) return;
            holder.mtxt.setText(datas.get(position - 1));
        }

        @Override
        public int getItemCount() {
            if (datas != null) {
                return datas.size() + 1;
            }
            else
                return 1;
        }

        class ViewHolder extends RecyclerView.ViewHolder {
            public TextView mtxt;
            public ViewHolder(View itemView) {
                super(itemView);
                mtxt = (TextView) itemView.findViewById(android.R.id.text1);
            }
        }
    }

效果图

噫噫噫？删除的时候分割线咋么没变？原因是 recycler.setHasFixedSize(true);这个啦，把这行代码删除就OK了哦

二、一步改变分割线样式

这里我们就把setHasFixedSize删除哈，其他代码不变
1. drawable下添加xml

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="180dp"/>
    <solid android:color="#006683"/>
    <size android:height="2dp" android:width="2dp"/>
</shape>

2. 在styles.xml中添加item,去修改listDivider的样式

        <item name="android:listDivider">@drawable/roundrect</item>

效果

三、关闭动画

    public void closeDefaultAnimator() {
        RecyclerView.ItemAnimator itemAnimator = recyclerView.getItemAnimator();
        itemAnimator.setAddDuration(0);
        itemAnimator.setChangeDuration(0);
        itemAnimator.setMoveDuration(0);
        itemAnimator.setRemoveDuration(0);
        ((SimpleItemAnimator) itemAnimator).setSupportsChangeAnimations(false);
    }

四、图片列表刷新闪烁解决

1. 首先关闭动画
2. 使用notifyItemRangeChanged进行刷新
   3.item的image设置tag，比较tag，相同时则不必在加载一次图片。