recycleView的使用

1.Datas:    要顯示的數據

2.Adapter：適配器，綁定數據集

3.ViewHolder：根據當前的數據保存視圖

4.LayoutManager：佈局管理器。決定item如何擺放

5.ItemDecoration：勉強理解爲item裝飾器，可以美化item

6. ItemAnimator：動畫（當item被增加，刪除，重新擺放時動畫纔有效）。

7. Listener： 事件。RecyclerView本身不提供OnItemClickListener等事件

所需庫文件：

compile 'com.android.support:recyclerview-v7:24.2.1'

佈局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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


    </android.support.v7.widget.RecyclerView>



</LinearLayout>

java文件：

private void initRecyclerView(View view) {
    mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerview);
    httpHelper.get(Contants.API.CAMPAIGN_HOME, new BaseCallback<List<HomeCampaign>>() {
        @Override
        public void onBeforeRequest(Request request) {
        }

        @Override
        public void onFailure(Request request, Exception e) {
        }

        @Override
        public void onResponse(Response response) {
        }

        @Override
        public void onSuccess(Response response, List<HomeCampaign> homeCampaigns) {
            initData(homeCampaigns);
        }

        @Override
        public void onError(Response response, int code, Exception e) {
        }
    });

}


private  void initData(List<HomeCampaign> homeCampaigns){
    mAdatper = new HomeCatgoryAdapter(homeCampaigns,getActivity());
    mAdatper.setOnCampaignClickListener(new HomeCatgoryAdapter.OnCampaignClickListener() {
        @Override
        public void onClick(View view, Campaign campaign) {
            Toast.makeText(getContext(),"title="+campaign.getTitle(),Toast.LENGTH_LONG).show();
        }
    });
    mRecyclerView.setAdapter(mAdatper);
    mRecyclerView.addItemDecoration(new CardViewtemDecortion());
    mRecyclerView.setLayoutManager(new LinearLayoutManager(this.getActivity()));
}

adapter文件：

public class HomeCatgoryAdapter extends RecyclerView.Adapter<HomeCatgoryAdapter.ViewHolder> {
    private  static int VIEW_TYPE_L=0;
    private  static int VIEW_TYPE_R=1;
    private LayoutInflater mInflater;
    private List<HomeCampaign> mDatas;
    private  Context mContext;
    private  OnCampaignClickListener mListener;
    public HomeCatgoryAdapter(List<HomeCampaign> datas,Context context){
        mDatas = datas;
        this.mContext = context;
    }

    public void setOnCampaignClickListener(OnCampaignClickListener listener){
        this.mListener = listener;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
        mInflater = LayoutInflater.from(viewGroup.getContext());
        if(type == VIEW_TYPE_R){
            return  new ViewHolder(mInflater.inflate(R.layout.template_home_cardview2,viewGroup,false));
        }
        return  new ViewHolder(mInflater.inflate(R.layout.template_home_cardview,viewGroup,false));
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int i) {
        HomeCampaign homeCampaign = mDatas.get(i);
        viewHolder.textTitle.setText(homeCampaign.getTitle());
        Picasso.with(mContext).load(homeCampaign.getCpOne().getImgUrl()).into(viewHolder.imageViewBig);
        Picasso.with(mContext).load(homeCampaign.getCpTwo().getImgUrl()).into(viewHolder.imageViewSmallTop);
        Picasso.with(mContext).load(homeCampaign.getCpThree().getImgUrl()).into(viewHolder.imageViewSmallBottom);
    }

    @Override
    public int getItemCount() {
        return mDatas.size();
    }


    @Override
    public int getItemViewType(int position) {
        if(position % 2==0){
            return  VIEW_TYPE_R;
        }
        else return VIEW_TYPE_L;
    }
      class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
        TextView textTitle;
        ImageView imageViewBig;
        ImageView imageViewSmallTop;
        ImageView imageViewSmallBottom;
        public ViewHolder(View itemView) {
            super(itemView);
            textTitle = (TextView) itemView.findViewById(R.id.text_title);
            imageViewBig = (ImageView) itemView.findViewById(R.id.imgview_big);
            imageViewSmallTop = (ImageView) itemView.findViewById(R.id.imgview_small_top);
            imageViewSmallBottom = (ImageView) itemView.findViewById(R.id.imgview_small_bottom);
            imageViewBig.setOnClickListener(this);
            imageViewSmallTop.setOnClickListener(this);
            imageViewSmallBottom.setOnClickListener(this);
        }

        @Override
        public void onClick(View v) {
            HomeCampaign homeCampaign = mDatas.get(getLayoutPosition());
            if(mListener !=null){
                switch (v.getId()){
                    case  R.id.imgview_big:
                        mListener.onClick(v,homeCampaign.getCpOne());
                        break;

                    case  R.id.imgview_small_top:
                        mListener.onClick(v,homeCampaign.getCpTwo());
                        break;

                    case  R.id.imgview_small_bottom:
                        mListener.onClick(v,homeCampaign.getCpThree());
                        break;
                }
            }
        }
    }

    public  interface OnCampaignClickListener{
        void onClick(View view, Campaign campaign);
    }

}

條目分割線文件

public class CardViewtemDecortion extends RecyclerView.ItemDecoration {

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        super.onDraw(c, parent, state);
    }

    @Override
    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
        super.onDrawOver(c, parent, state);
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int layoutOrientation = getOrientation(parent);
        if (layoutOrientation == LinearLayoutManager.VERTICAL) {
            outRect.top = 10;
            outRect.left=5;
            outRect.right=5;
        } else if(layoutOrientation == LinearLayoutManager.HORIZONTAL) {
            outRect.left = 5;
        }
    }

    private int getOrientation(RecyclerView parent) {
        if (parent.getLayoutManager() instanceof LinearLayoutManager) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
            return layoutManager.getOrientation();
        } else throw new IllegalStateException("DividerItemDecoration can only be used with a LinearLayoutManager.");
    }
}