RecycleView的实现步骤:
1.搭建环境:由于RecycleView是在android5.0之后出来的,用来代替listview,以前的版本能用。需要添加包
选择recycleview-v7包
2.布局文件添加recycleview
<android.support.v7.widget.RecyclerView
android:id="@+id/recycle_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
3.实例化RecycleView控件
4.创建DataBean类,存放bean属性
5.创建LoadListData()方法,给RecycleView填充数据
private void LoadListData() {
//集合对象
ArrayList<DataBean> list = new ArrayList<>();
//给Bean类放数据,最后把装好数据的Bean类放到集合里
for(int i=0;i<35;i++){
//创建Bean类对象,
DataBean bean = new DataBean();
bean.icon = R.drawable.animal01;
bean.name = "dog"+i;
//把Bean类放入集合里
list.add(bean);
}
}
6.在主方法中调用LoadListData()方法;
7.创建MyRecycleAdapter适配器,并配置
(1)创建适配器Myadapter继承自RecyclerView.Adapter<Myadapter.listViewHolder>,并实现内部的方法;
(2)在适配器中创建构造方法:
(3)在实现的public MyRecycleAdapter.ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 方法中创建ViewHolder,并把ViewHolder返回出去,
①先转换一个View布局,决定了item的样子, 参数:1.上下文 2.Xml布局资源 3.为null,
View view = View.inflate(mContext, R.layout.item, null);
②创建item布局
item布局代码:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/item_iv_icon"
android:layout_width="75dp"
android:layout_height="75dp"/>
<TextView
android:layout_centerVertical="true"
android:layout_toRightOf="@+id/item_iv_icon"
android:textSize="30sp"
android:id="@+id/item_tv_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</RelativeLayout>
③创建ViewHolder,并把ViewHolder返回出去代码:public MyRecycleAdapter.ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//转换一个View布局,决定了item的样子, 参数:1.上下文 2.Xml布局资源 3.为null
View view = View.inflate(mContext, R.layout.item, null);
//创建一个ViewHolder对象
ListViewHolder listViewHolder = new ListViewHolder(view);
//把VIewHolder对象传出去
return listViewHolder;
}
(4)当VIewHolder和数据绑定时回调
代码:public void onBindViewHolder(ListViewHolder holder, int position) {
//从集合里拿对应item数据对象
DataBean dataBean = mDataBeen.get(position);
//给holder里面的控件对象设置数据
holder.setData(dataBean);
}
(5)决定RecycleView有多少条item
代码:public int getItemCount() {
//数据不为空,有几条数据就显示几条数据
if(list!=null&&list.size()>0){
return list.size();
}
return 0;
(6)配置自动帮我们写的ViewHolder,参数View布局对象
代码:
public class ListViewHolder extends RecyclerView.ViewHolder {
private final ImageView mIcon;
private final TextView mTextView;
public ListViewHolder(View itemView) {
super(itemView);
mIcon = (ImageView)itemView.findViewById(R.id.item_iv_icon);
mTextView = (TextView) itemView.findViewById(R.id.item_tv_text);
}
public void setData(DataBean data) {
//给ImageView设置图片数据
mIcon.setImageResource(data.icon);
//给TextView设置文本数据
mTextView.setText(data.name);
}
}
8.创建适配器MyRecycleAdapter对象 参数:1.上下文2.数据加载集合;
MyRecycleAdapter adapter = new MyRecycleAdapter(this,list);
9.设置适配器
recyclerView.setAdapter(adapter);
10.布局管理器所需参数, 上下文
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
11.设置布局管理器,参数linearLayoutManager对象
recyclerView.setLayoutManager(linearLayoutManager);
MainAcitivity代码:
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recycle_view);
LoadListData();
}
private void LoadListData() {
//集合对象
ArrayList<DataBean> list = new ArrayList<>();
//给Bean类放数据,最后把装好数据的Bean类放到集合里
for(int i=0;i<35;i++){
//创建Bean类对象,
DataBean bean = new DataBean();
bean.icon = R.drawable.animal01;
bean.name = "dog"+i;
//把Bean类放入集合里
list.add(bean);
}
//创建适配器Adapter对象 参数:1.上下文2.数据加载集合
MyRecycleAdapter adapter = new MyRecycleAdapter(this,list);
//设置适配器
recyclerView.setAdapter(adapter);
//布局管理器所需参数, 上下文
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
//设置布局管理器,参数linearLayoutManager对象
recyclerView.setLayoutManager(linearLayoutManager);
}
}
MyRecycleAdapterdaima ://RecycleView的适配器,要注意指定的泛型,一般我们就是类名的ViewHolder继承ViewHolder(内部已经实现了复用优化机制)
public class MyRecycleAdapter extends RecyclerView.Adapter<MyRecycleAdapter.ListViewHolder>{
private Context mContext;
//泛型是RecycleView所需的bean类
private List<DataBean>list;
//创建构造方法;一个需要接受两个参数,上下文,集合对象(包含了我们所需要的数据)
public MyRecycleAdapter(Context context, List<DataBean> list) {
mContext = context;
this.list = list;
}
@Override
//创建ViewHolder,并把ViewHolder返回出去
public MyRecycleAdapter.ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//转换一个View布局,决定了item的样子, 参数:1.上下文 2.Xml布局资源 3.为null
View view = View.inflate(mContext, R.layout.item, null);
//创建一个ViewHolder对象
ListViewHolder listViewHolder = new ListViewHolder(view);
//把VIewHolder对象传出去
return listViewHolder;
}
@Override
//当VIewHolder和数据绑定时回调
public void onBindViewHolder(MyRecycleAdapter.ListViewHolder holder, int position) {
//从集合里拿对应item数据对象
DataBean dataBean = list.get(position);
//给Holder里面的控件对象设置数据
holder.setData(dataBean);
}
@Override
//决定RecycleView有多少条item
public int getItemCount() {
if(list!=null&&list.size()>0){
return list.size();
}
return 0;
}
public class ListViewHolder extends RecyclerView.ViewHolder {
private final ImageView mIcon;
private final TextView mTextView;
public ListViewHolder(View itemView) {
super(itemView);
mIcon = (ImageView)itemView.findViewById(R.id.item_iv_icon);
mTextView = (TextView) itemView.findViewById(R.id.item_tv_text);
}
public void setData(DataBean data) {
//给ImageView设置图片数据
mIcon.setImageResource(data.icon);
//给TextView设置文本数据
mTextView.setText(data.name);
}
}
}