RecycleView的實現步驟:
1.搭建環境:由於RecycleView是在android5.0之後出來的,用來代替listview,以前的版本能用。需要添加包
選擇recycleview-v7包
2.佈局文件添加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.實例化RecycleView控件
4.創建DataBean類,存放bean屬性
5.創建LoadListData()方法,給RecycleView填充數據
private void LoadListData() {
//集合對象
ArrayList<DataBean> list = new ArrayList<>();
//給Bean類放數據,最後把裝好數據的Bean類放到集合裏
for(int i=0;i<35;i++){
//創建Bean類對象,
DataBean bean = new DataBean();
bean.icon = R.drawable.animal01;
bean.name = "dog"+i;
//把Bean類放入集合裏
list.add(bean);
}
}
6.在主方法中調用LoadListData()方法;
7.創建MyRecycleAdapter適配器,並配置
(1)創建適配器Myadapter繼承自RecyclerView.Adapter<Myadapter.listViewHolder>,並實現內部的方法;
(2)在適配器中創建構造方法:
(3)在實現的public MyRecycleAdapter.ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 方法中創建ViewHolder,並把ViewHolder返回出去,
①先轉換一個View佈局,決定了item的樣子, 參數:1.上下文 2.Xml佈局資源 3.爲null,
View view = View.inflate(mContext, R.layout.item, null);
②創建item佈局
item佈局代碼:
<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創建ViewHolder,並把ViewHolder返回出去代碼:public MyRecycleAdapter.ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//轉換一個View佈局,決定了item的樣子, 參數:1.上下文 2.Xml佈局資源 3.爲null
View view = View.inflate(mContext, R.layout.item, null);
//創建一個ViewHolder對象
ListViewHolder listViewHolder = new ListViewHolder(view);
//把VIewHolder對象傳出去
return listViewHolder;
}
(4)當VIewHolder和數據綁定時回調
代碼:public void onBindViewHolder(ListViewHolder holder, int position) {
//從集合裏拿對應item數據對象
DataBean dataBean = mDataBeen.get(position);
//給holder裏面的控件對象設置數據
holder.setData(dataBean);
}
(5)決定RecycleView有多少條item
代碼:public int getItemCount() {
//數據不爲空,有幾條數據就顯示幾條數據
if(list!=null&&list.size()>0){
return list.size();
}
return 0;
(6)配置自動幫我們寫的ViewHolder,參數View佈局對象
代碼:
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) {
//給ImageView設置圖片數據
mIcon.setImageResource(data.icon);
//給TextView設置文本數據
mTextView.setText(data.name);
}
}
8.創建適配器MyRecycleAdapter對象 參數:1.上下文2.數據加載集合;
MyRecycleAdapter adapter = new MyRecycleAdapter(this,list);
9.設置適配器
recyclerView.setAdapter(adapter);
10.佈局管理器所需參數, 上下文
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
11.設置佈局管理器,參數linearLayoutManager對象
recyclerView.setLayoutManager(linearLayoutManager);
MainAcitivity代碼:
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() {
//集合對象
ArrayList<DataBean> list = new ArrayList<>();
//給Bean類放數據,最後把裝好數據的Bean類放到集合裏
for(int i=0;i<35;i++){
//創建Bean類對象,
DataBean bean = new DataBean();
bean.icon = R.drawable.animal01;
bean.name = "dog"+i;
//把Bean類放入集合裏
list.add(bean);
}
//創建適配器Adapter對象 參數:1.上下文2.數據加載集合
MyRecycleAdapter adapter = new MyRecycleAdapter(this,list);
//設置適配器
recyclerView.setAdapter(adapter);
//佈局管理器所需參數, 上下文
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
//設置佈局管理器,參數linearLayoutManager對象
recyclerView.setLayoutManager(linearLayoutManager);
}
}
MyRecycleAdapterdaima ://RecycleView的適配器,要注意指定的泛型,一般我們就是類名的ViewHolder繼承ViewHolder(內部已經實現了複用優化機制)
public class MyRecycleAdapter extends RecyclerView.Adapter<MyRecycleAdapter.ListViewHolder>{
private Context mContext;
//泛型是RecycleView所需的bean類
private List<DataBean>list;
//創建構造方法;一個需要接受兩個參數,上下文,集合對象(包含了我們所需要的數據)
public MyRecycleAdapter(Context context, List<DataBean> list) {
mContext = context;
this.list = list;
}
@Override
//創建ViewHolder,並把ViewHolder返回出去
public MyRecycleAdapter.ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//轉換一個View佈局,決定了item的樣子, 參數:1.上下文 2.Xml佈局資源 3.爲null
View view = View.inflate(mContext, R.layout.item, null);
//創建一個ViewHolder對象
ListViewHolder listViewHolder = new ListViewHolder(view);
//把VIewHolder對象傳出去
return listViewHolder;
}
@Override
//當VIewHolder和數據綁定時回調
public void onBindViewHolder(MyRecycleAdapter.ListViewHolder holder, int position) {
//從集合裏拿對應item數據對象
DataBean dataBean = list.get(position);
//給Holder裏面的控件對象設置數據
holder.setData(dataBean);
}
@Override
//決定RecycleView有多少條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) {
//給ImageView設置圖片數據
mIcon.setImageResource(data.icon);
//給TextView設置文本數據
mTextView.setText(data.name);
}
}
}