RecycleView 实现瀑布流效果

1、用as开发，在build.gradle中添加依赖

dependencies {
...
compile 'com.android.support:recyclerview-v7:21.0.3'
}

2、用Eclipse开发，添加jar包

3、在xml布局文件中添加一个recycleview的布局

<android.support.v7.widget.RecyclerView
android:id="@+id/card_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="7dp"
android:layout_marginTop="5dp"
android:scrollbars="vertical" />

4、activity的oncreate方法中添加如下关键代码

View view = inflater.inflate(R.layout.card_recycleview, null);
card_recycler_view = (RecyclerView) view.findViewById(R.id.card_recycler_view);
card_recycler_view.setHasFixedSize(false);
StaggeredGridLayoutManager mStaggeredGridLayoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);//表示两列，并且是竖直方向的瀑布流
card_recycler_view.setLayoutManager(mStaggeredGridLayoutManager);

5、创建recycleview的数据适配器

public class RenQiAdapter2 extends RecyclerView.Adapter<RenQiAdapter2.ViewHolder> implements View.OnClickListener {

private List<StoreContent> data;//填充数据的集合
protected ImageLoader imageLoader = ImageLoader.getInstance();//采用universal imageloader来加载图片

public RenQiAdapter2(List<StoreContent> data) {
this.data = data;
}

public void setData(List<StoreContent> data) {
this.data = data;
}

@Override
public RenQiAdapter2.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_store_detail_item, viewGroup, false);
ViewHolder vh = new ViewHolder(view);
view.setOnClickListener(this);
return vh;
}

@Override
public void onBindViewHolder(final RenQiAdapter2.ViewHolder viewHolder, final int i) {
viewHolder.itemView.setTag(data.get(i));
viewHolder.iv_store.setImageResource(R.drawable.whitebottom);
viewHolder.iv_store.setTag(data.get(i).getCoverUrl());
imageLoader.loadImage(data.get(i).getCoverUrl(), BaseConstants.optionscopy, new ImageLoadingListener() {
@Override
public void onLoadingStarted(String s, View view) {

}

@Override
public void onLoadingFailed(String s, View view, FailReason failReason) {

}

@Override
public void onLoadingComplete(String imgUrl, View view, Bitmap bitmap) {
if (viewHolder.iv_store.getTag() != null
&& viewHolder.iv_store.getTag().equals(imgUrl)) {
//此处代码获取屏幕的宽高，实现不同屏幕的适配
int width = BaseApplication.getWindowWidth() / 2;
int height = width * bitmap.getHeight() / bitmap.getWidth();//高通过宽等比例缩放
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
width, height);
viewHolder.iv_store.setLayoutParams(params);
viewHolder.iv_store.setImageBitmap(bitmap);

viewHolder.tv_date.setText("总销"
+ data.get(i).getSale() + "件");
viewHolder.tv_price.setText("¥ "
+ CommonUtils.getShortPrice(
data.get(i).getSalePrice(),
2));
}
}

@Override
public void onLoadingCancelled(String s, View view) {

}
});
}

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

@Override
public void onClick(View v) {
if (null != mOnItemClickListener) {
mOnItemClickListener.onClick(v, (StoreContent) v.getTag());
}
}

//创建一个viewholder类
public static class ViewHolder extends RecyclerView.ViewHolder {
ImageView iv_store;
TextView tv_date;
TextView tv_price;

public ViewHolder(View itemView) {
super(itemView);
iv_store = (ImageView) itemView.findViewById(R.id.iv_store);
tv_date = (TextView) itemView.findViewById(R.id.tv_date);
tv_price = (TextView) itemView.findViewById(R.id.tv_price);
}
}

private OnRecyclerViewItemClickListener mOnItemClickListener = null;

public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {
this.mOnItemClickListener = listener;
}

public static interface OnRecyclerViewItemClickListener {
void onClick(View view, StoreContent itemData);
}
}

注：recycleview的数据适配器，继承RecycleView.Adapter的子类，此处继承的是我在本类中定义的ViewHolder。强制重写的方法：

onCreateViewHolder(),onBindViewHolder(),和getItemCount();

在onCreateViewHolder(),方法中，需要返回，与当前adapter绑定的viewholder；

在onBindViewHolder()方法中，将数据填充到控件中；

getItemCont()的作用与listview的adapter方法中的getItemCount()一样。

6、给RecycleView添加adapter

if (null == rebateAdapter) {
rebateAdapter = new RebateAdapter(activity, value);
card_staggeredgridview.setAdapter(rebateAdapter);
card_staggeredgridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
RebateDetail item = (RebateDetail) card_staggeredgridview.getAdapter().getItem(position);
...
}
});
} else {
rebateAdapter.setData(value);
rebateAdapter.notifyDataSetChanged();
}

7、RecycleView仿造listview的onItemClick方法

7.1在adapter中定义一个接口，和抽象方法；

public static interface OnRecyclerViewItemClickListener {
void onClick(View view, StoreContent itemData);
}

7.2在adapter中定义一接口对象，并添加set方法；

private OnRecyclerViewItemClickListener mOnItemClickListener = null;

public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {
this.mOnItemClickListener = listener;
}

7.3adapter类实现View的onClickListener接口，重写抽象方法

public class RenQiAdapter2 extends RecyclerView.Adapter<RenQiAdapter2.ViewHolder> implements View.OnClickListener {
.......
@Override
public void onClick(View v) {
if (null != mOnItemClickListener) {
mOnItemClickListener.onClick(v, (StoreContent) v.getTag());
}
}
}

7.4 在bindviewholder方法中，将数据传递给view

@Override
public void onBindViewHolder(final RenQiAdapter2.ViewHolder viewHolder, final int i) {
......
viewHolder.itemView.setTag(data.get(i));
......
}

7.5 给recycleview添加onitemclick方法

card_staggeredgridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
RebateDetail item = (RebateDetail) card_staggeredgridview.getAdapter().getItem(position);
Intent intent = new Intent(activity, BaoBeiDetailActivity.class);
intent.putExtra("itemid", item.getItemId());
intent.putExtra("clickPostion", position);
activity.startActivity(intent);
activity.overridePendingTransition(R.anim.tran_in, R.anim.tran_out);
}
});

8、RecycleView 的数据更新

listview中更新数据，通过的方法是notifyDataSetChanged()

RecycleView中，可以只更新一条数据

在adapter类中，定义如下方法；可以在其他地方调用

public void changeData(int position){
notifyItemChanged(position);
}

public void addData(int position){
notifyItemInserted(position);
}
public void removeData(int position){
notifyItemRemoved(position);
}