RecyclerView
一种可以替换掉listview gridview 瀑布流等控件的新视图控件，控制视图回收和复用 ==优化内存可以替换listview
与listview的不同之处是：listview缓存convertview不同的是,Recyclerview缓存的是viewholder.
提供了一种插拔式的体验，高度的解耦，异常的灵活，通过设置它提供的不同LayoutManager，ItemDecoration , ItemAnimator实现想要的效果
1、RecyclerView.Adapter 适配器
2、RecyclerView.ItemDecoration 每个item附加的子视图，可用来绘制Divider,设置padding等
3、RecyclerView.ItemAnimator 负责添加、删除数据时的动画效果
4、RecyclerView.ViewHolder 缓存的对象
5、RecyclerView.LayoutManager 布局器，负责Item视图的布局
具体使用1、activity：
private Activity activity;
private List<PicData> mpicDatas;
private MyAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recycleview);
activity = this;
// 获取recycleView 设置布局管理器 设置items 分割线 设置 item 动画
RecyclerView my_recycleview = (RecyclerView) this
.findViewById(R.id.my_recycleview);
my_recycleview.setLayoutManager(new LinearLayoutManager(
getApplicationContext()));
my_recycleview.setItemAnimator(new DefaultItemAnimator());// 设置默认的动画
mpicDatas = Tool.getData();
adapter = new MyAdapter(mpicDatas);
adapter.setOnMyItemClickListener(new OnMyItemClickListener() {
@Override
public void OnItemClick(View view, int position) {
Toast.makeText(activity, "Click" + mpicDatas.get(position),
Toast.LENGTH_SHORT).show();
adapter.removeData(position);
}
@Override
public void OnItemLongClick(View view, int position) {
Toast.makeText(activity, "LongClick" + mpicDatas.get(position),
Toast.LENGTH_SHORT).show();
adapter.addData(position, mpicDatas.get(position));
}
});
my_recycleview.setAdapter(adapter);
// 自定义动画有问题
// my_recycleview.setItemAnimator(new MyItemAnimator());
}
2、适配器 要处理点击事件和对应的视图处理：
// 提供 个数 和viewholder 已经绑定数据 onBindViewHolder
// 触发事件 和动画效果需要自己灵活处理
public class MyAdapter extends RecyclerView.Adapter<ViewHolder> {
List<PicData> mpicdatas;
private OnMyItemClickListener mOnItemClickListener;
public MyAdapter() {
}
public MyAdapter(List<PicData> mpicdatas) {
this.mpicdatas = mpicdatas;
}
public MyAdapter(List<PicData> mpicdatas,
OnMyItemClickListener mOnItemClickListener) {
this.mpicdatas = mpicdatas;
this.mOnItemClickListener = mOnItemClickListener;
}
// 移除数据
public void removeData(int po) {
if(po>mpicdatas.size()-1){
return;
}
mpicdatas.remove(po);
notifyItemRemoved(po);
}
// 指定位置添加数据
public void addData(int po, PicData mPicData) {
if(po>mpicdatas.size()){
po=mpicdatas.size();
}
if(po<0){
po=0;
}
mpicdatas.add(po, mPicData);
notifyItemInserted(po);
}
// 获取对象个数
@Override
public int getItemCount() {
return mpicdatas.size();
}
// 具体用于绑定对应数据
@Override
public void onBindViewHolder(ViewHolder mViewHolder1, int arg1) {
final MyViewHolder mViewHolder = (MyViewHolder) mViewHolder1;
PicData mPicData = mpicdatas.get(arg1);
// mViewHolder.im.setBackground(background)
mViewHolder.tv_des.setText(mPicData.getDes());
mViewHolder.tv_name.setText(mPicData.getName());
// 设置点击事件
if (mOnItemClickListener != null) {
// 判断是否设置过点击事件 如果设置过 不再设置 防止重复创建 增加内存开销
if (!mViewHolder.itemView.hasOnClickListeners()) {
mViewHolder.itemView
.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
int po = mViewHolder.getPosition();
mOnItemClickListener.OnItemClick(v, po);
}
});
mViewHolder.itemView
.setOnLongClickListener(new OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
int po = mViewHolder.getPosition();
mOnItemClickListener.OnItemLongClick(v, po);
return true;
}
});
}
}
}
// 创建一个可返回的holder 用于回收和复用
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int arg1) {
MyViewHolder holder = new MyViewHolder(LayoutInflater.from(
RecycleviewActivity.this).inflate(
R.layout.activity_recycleview_item, parent, false));
return holder;
}
// viewholder 静态内部类
class MyViewHolder extends ViewHolder {
private TextView tv_name;
private TextView tv_des;
private ImageView im;
public MyViewHolder(View view) {
super(view);
tv_name = (TextView) view.findViewById(R.id.tv_title);
tv_des = (TextView) view.findViewById(R.id.tv_des);
im = (ImageView) view.findViewById(R.id.im_holder);
}
}
// 设置点击事件
public void setOnMyItemClickListener(
OnMyItemClickListener mOnItemClickListener) {
this.mOnItemClickListener = mOnItemClickListener;
}
}
3、点击事件的接口
import android.view.View;
public interface OnMyItemClickListener {
public void OnItemClick(View view, int position);
public void OnItemLongClick(View view, int position);
}
4、model
public class PicData {
private String name;
private String des;
private String path;
public PicData() {
}
public PicData(String name, String des, String path) {
this.des = des;
this.name = name;
this.path = path;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDes() {
return des;
}
public void setDes(String des) {
this.des = des;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
}
5、工具
public class Tool {
/**
* 获取对应的测试数据
* @return
*/
public static List<PicData> getData(){
String image[]={
"http://imgsrc.baidu.com/forum/w%3D580/sign=f786dbba8744ebf86d716437e9f8d736/9fe5546034a85edf11571c9a49540923df547580.jpg",
"http://upload.wendu.cn/2016/0225/thumb_300_0_1456366681530.jpg",
"http://upload.wendu.cn/2016/0225/thumb_300_0_1456386396842.jpg",
"http://upload.wendu.cn/2016/0225/thumb_300_0_1456386399211.jpg",
"http://upload.wendu.cn/2016/0217/thumb_300_0_1455684747338.jpg",
"http://upload.wendu.cn/2016/0203/thumb_300_0_1454499202633.png",
"http://upload.wendu.cn/2016/0122/thumb_300_0_1453463650114.jpg",
"http://upload.wendu.cn/2016/0123/thumb_213_160_1453513340130.png",
"http://upload.wendu.cn/2016/0129/thumb_300_0_1454030278472.jpg"
};
List<PicData> mlist=new ArrayList<PicData>();
for(int i=0;i<image.length;i++){
mlist.add(new PicData("第几张"+i, "测试第几张图片 测试数据"+i, image[i]));
}
return mlist;
}
}
6、布局
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<android.support.v7.widget.RecyclerView
android:id="@+id/my_recycleview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</RelativeLayout>