[置顶] RecyclerView的使用

RecyclerView可以去替换ListView 和GridView
RecyclerView相比较ListView和GridView，它高度解耦，更加灵活，
自带默认的动画效果，可以自定义多种样式的分割线
可以轻易的是想瀑布流效果，对于拖动比较好实现…..
以上的实现原理是通过设置LayoutManager，ItemDecoration , ItemAnimator实现令人瞠目的效果
LayoutManager是控制器显示方式，有ListView效果，GridView效果，GridView横向滑动，横/竖瀑布流
ItemDecoration是控制item的间距，同时可绘制分隔线
ItemAnimator控制item的增删动画，默认效果已经很不错了
还有个开源库RecyclerViewItemAnimators可以实现跟多效果

开始

<android.support.v7.widget.RecyclerView
 android:id="@+id/id_recyclerview"
android:divider="#ffff0000"
android:dividerHeight="10dp"
android:layout_width="match_parent"
android:layout_height="match_parent" />

<!--item 的布局文件代码-->
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:background="#44ff0000"
android:layout_height="wrap_content" >

<TextView
 android:id="@+id/id_num"
android:layout_width="match_parent"
android:layout_height="50dp"
android:gravity="center"
android:text="1" />
</FrameLayout>

//这个是设置显示方式
//  mRecyclerView.setLayoutManager(new LinearLayoutManager(activity));listview显示
//  mRecyclerView.setLayoutManager(new GridLayoutManager(activity,4));//gridview显示
//  mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL));//gridview行显示，瀑布流必须设置item的高度 向左右滑动
//  mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(8, StaggeredGridLayoutManager.HORIZONTAL)); //gridview列显示，瀑布流必须设置item的宽度，否则会出问题



//设置分隔符，自定义样式，默认样式自定义高度颜色
//        mRecyclerView.addItemDecoration(new DividerItemDecoration(activity,DividerItemDecoration.VERTICAL_LIST));//默认样式，灰色，1px竖线
//        mRecyclerView.addItemDecoration(new DividerItemDecoration(activity,DividerItemDecoration.HORIZONTAL_LIST));默认样式，灰色，1px横线
//        mRecyclerView.addItemDecoration(new DividerItemDecoration(activity,DividerItemDecoration.VERTICAL_LIST,R.drawable.divider));//自定义的样式传入一个自定义的样式
//        mRecyclerView.addItemDecoration(new DividerItemDecoration(activity,DividerItemDecoration.VERTICAL_LIST,10, Color.RED));可以自定义颜色，自定义宽度
//        mRecyclerView.addItemDecoration(new DividerGridItemDecoration(activity,R.drawable.divider));//自定义的样式
//        mRecyclerView.addItemDecoration(new DividerGridItemDecoration(activity,10));//第二个参数宽度

//设置动画效果
//        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
//重点来了，设置适配器
// mRecyclerView.setAdapter( mAdapter = new HomeAdapter());

//一定样继承RecyclerView.Adapter，并且在泛型中传入holder类，并且 它必须继承于RecyclerView.ViewHolder
class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {

        @Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            MyViewHolder holder = new MyViewHolder(LayoutInflater.from(
                    activity).inflate(R.layout.item_home, parent,false));
return holder;
        }

        @Override
public void onBindViewHolder(MyViewHolder holder, int position) {
            holder.tv.setText(mDatas.get(position));
//我这里是为了显示瀑布流自己生成的随机数，
//设置不同的宽高，我怕随机产生的数过小，效果不明显，对随机数的大小做了限制，
int a = new Random().nextInt(200);
            ViewGroup.LayoutParams ab= holder.tv.getLayoutParams();
if (a > 100) {
                ab.height=a;
                holder.tv.setLayoutParams(ab);
            }else {
                ab.height=100;
                holder.tv.setLayoutParams(ab);
            }
            Log.e("a",a+"");
        }

//用于显示多少条数据
        @Override
public int getItemCount() {
return mDatas.size();
        }
//这里是模拟添加和移除的动画效果
public void addData(int position) {
            mDatas.add(position, "Insert One");
//注意这里面不再用的是adapter.notifyDataSetChanged()；
//而是adapter.notifyItemInserted(position)；添加到第几个item的地方
            notifyItemInserted(position);
        }

public void removeData(int position) {
            mDatas.remove(position);
//而是adapter.notifyItemRemoved(position)；移除第几个item
            notifyItemRemoved(position);
        }

//这里虽然集成了RecyclerView.ViewHolder，但是，书写的样式跟listview没差别
class MyViewHolder extends RecyclerView.ViewHolder {

            TextView tv;

public MyViewHolder(View view) {
super(view);
                tv = (TextView) view.findViewById(R.id.id_num);
            }
        }
    }



    在Activity中去设置监听
        mAdapter.setOnItemClickLitener(new OnItemClickLitener()
        {

            @Override
public void onItemClick(View view, int position)
            {
//点击
                Toast.makeText(HomeActivity.this, position + " click",
                        Toast.LENGTH_SHORT).show();
            }

            @Override
public void onItemLongClick(View view, int position)
            {
//长按
                Toast.makeText(HomeActivity.this, position + " long click",
                        Toast.LENGTH_SHORT).show();
                        mAdapter.removeData(position);
            }
        });