[Android Pro] RecyclerView实现瀑布流效果（二）

referece to : http://blog.csdn.net/u010687392

在上篇中我们知道RecyclerView中默认给我们提供了三种布局管理器，分别是LinearLayoutManager、 GridLayoutManager、StaggeredGridLayoutManager。其中 StaggeredGridLayoutManager可实现交错式网格布局，正好可以用来实现瀑布流。

下面先看看效果图吧，再贴代码：

其中大部分内容实现其实是和上篇文章是一样的，就不多叙述了，就一个地方不同，就是我们在适配器中绑定ViewHolder的方法中需要重新给我们的itemView布局设置height，我这里是生成随机数来设置高度的，代码实现为：

private void getRandomHeight(List<String> lists){//得到随机item的高度
       heights = new ArrayList<>();
       for (int i = 0; i < lists.size(); i++) {
           heights.add((int)(200+Math.random()*400));
       }
   }

在onBindViewHolder方法中：

ViewGroup.LayoutParams params =  holder.itemView.getLayoutParams();//得到item的LayoutParams布局参数
params.height = heights.get(position);//把随机的高度赋予itemView布局
holder.itemView.setLayoutParams(params);//把params设置给itemView布局

从而实现瀑布流效果。

贴一下代码吧：

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private RecyclerView mRecyclerView;
    private List<String> lists;
    private MyRecyclerAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        mRecyclerView = (RecyclerView) this.findViewById(R.id.recyclerView);
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
//        mRecyclerView.addItemDecoration();//设置分割线
        mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL));//设置RecyclerView布局管理器为2列垂直排布
       adapter = new MyRecyclerAdapter(this,lists);
        mRecyclerView.setAdapter(adapter);
        adapter.setOnClickListener(new MyRecyclerAdapter.OnItemClickListener() {
            @Override
            public void ItemClickListener(View view, int postion) {
                Toast.makeText(MainActivity.this,"点击了："+postion,Toast.LENGTH_SHORT).show();
            }
            @Override
            public void ItemLongClickListener(View view, int postion) {
                //长按删除
                lists.remove(postion);
                adapter.notifyItemRemoved(postion);
            }
        });
    }

    private void initData() {
        lists = new ArrayList();
        for (int i = 0; i < 100; i++) {
            lists.add("" + i);
        }
    }

}

MyRecyclerAdapter.java

public class MyRecyclerAdapter extends RecyclerView.Adapter<MyViewHolder> {
    private List<String> lists;
    private Context context;
    private List<Integer> heights;
    private OnItemClickListener mListener;
    public MyRecyclerAdapter(Context context,List<String> lists) {
        this.context = context;
        this.lists = lists;
        getRandomHeight(this.lists);
    }
    private void getRandomHeight(List<String> lists){//得到随机item的高度
        heights = new ArrayList<>();
        for (int i = 0; i < lists.size(); i++) {
            heights.add((int)(200+Math.random()*400));
        }
    }
    public interface OnItemClickListener{
        void ItemClickListener(View view,int postion);
        void ItemLongClickListener(View view,int postion);
    }
    public void setOnClickListener(OnItemClickListener listener){
        this.mListener = listener;
    }
    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item,parent,false);
        MyViewHolder viewHolder = new MyViewHolder(view);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(final MyViewHolder holder, int position) {
        ViewGroup.LayoutParams params =  holder.itemView.getLayoutParams();//得到item的LayoutParams布局参数
        params.height = heights.get(position);//把随机的高度赋予item布局
        holder.itemView.setLayoutParams(params);//把params设置给item布局

        holder.mTv.setText(lists.get(position));//为控件绑定数据
        if(mListener!=null){//如果设置了监听那么它就不为空，然后回调相应的方法
            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                int pos = holder.getLayoutPosition();//得到当前点击item的位置pos
                mListener.ItemClickListener(holder.itemView,pos);//把事件交给我们实现的接口那里处理
                }
            });
            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View v) {
                    int pos = holder.getLayoutPosition();//得到当前点击item的位置pos
                    mListener.ItemLongClickListener(holder.itemView,pos);//把事件交给我们实现的接口那里处理
                    return true;
                }
            });
        }
    }

    @Override
    public int getItemCount() {
        return lists.size();
    }
}
class MyViewHolder extends RecyclerView.ViewHolder{
    TextView mTv;
    public MyViewHolder(View itemView) {
        super(itemView);
        mTv = (TextView) itemView.findViewById(R.id.textView);
    }
}

源码下载地址：http://www.it165.net/uploadfile/files/2015/0705/recyclerView2.rar

转载请注明出处-http://blog.csdn.net/u010687392