The use of adapters for ListView includes adapters such as ArrayAdapter, SimpleAdapter, and BaseAdapter.
1:ArrayAdapter
- /****
- *
- *
- * ArrayAdapter
- * @author Administrator
- *
- */
- publicclass ArrayAdapterActivity extends Activity {
- private ListView mListView;
- //Define a String array, the data in the array is an item in the ListView
- String[] arrayDate={ "Swordsman" , "Feng Qingyang" , "Linghu Chong" , "Yue Buqun" , "Qiao Feng" , "Xuzhu" , "Duan Yu" , "Zhong Shentong" , "East Evil" , "Western Poison" , "Southern Emperor" , "Northern Beggar" };
- @Override
- protectedvoid onCreate(Bundle savedInstanceState) {
- super .onCreate (savedInstanceState);
- setContentView(R.layout.activity_arrayadapter);
- initView();
- }
- privatevoid initView() {
- mListView=(ListView)findViewById(R.id.listView1);
- //Create a new array adapter ArrayAdapter to bind data, parameters (current Activity, layout file, data source)
- //android.R.layout.simple_list_item_1 has its own layout
- ArrayAdapter<String> adapter=new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1,arrayDate);
- //View (ListView) loads the adapter
- mListView.setAdapter(adapter);
- mListView.setOnItemClickListener(new OnItemClickListener() {
- @Override
- public voidonItemClick(AdapterView<?> parent, View view,
- int position,long id) {
- Toast.makeText(ArrayAdapterActivity.this,arrayDate[position],1).show();
- }
- });
- }
- }
Preview effect:
2:SimpleAdapter
The data using simpleAdapter is generally a List composed of HashMap, and each section of the list corresponds to each row of the ListView. Each key-value data of the HashMap is mapped to the component with the corresponding id in the layout file.
Induction step:
1. Prepare the data source: specify the List data source composed of Map
2. Create a new adapter, set the key value name and the corresponding control id, and bind the data
3. View Loading Adapter
parameter:
new SimpleAdapter(context, data, resource, from, to)
context ------The running environment of the View associated with the SimpleAdapter
data --------- A List of Maps. Each entry in the list corresponds to a row in the list, and each map should contain all the keys specified in the from parameter
resource ------ The resource ID of a layout file that defines the list item. The layout file will contain at least those IDs defined in to
from ---------- a key that will be added to the Map
to -------------The ID of the view bound to the data corresponds to the from parameter
Code:
- /****
- *
- *
- * SimpleAdapter
- *
- * @author Administrator
- *
- */
- publicclass SimpleAdapterActivity extends Activity {
- private ListView mshow_list;
- String[] name = { "张三","李四","小星星","静静","明明","小张" };
- int[] img = {R.drawable.a2, R.drawable.a3,R.drawable.a4, R.drawable.a5,R.drawable.a6,R.drawable.ic_launcher};
- protected void onCreate(android.os.Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- //加载布局文件
- setContentView(R.layout.activity_simpleadapter);
- //2.获取listview控件的对象
- mshow_list=(ListView)findViewById(R.id.show_listview);
- /**
- * 第四步:定义SimpleAdapter(并加载对应item布局文件,获得对应的keY,获得对应item布局文件中的组件的id
- *
- * 第二个参数data:数据源
- * 第三个参数resource :listView每个item对应的布局文件
- * 第四个参数 from:
- * 第五个参数to:
- *new String[]{对应的key}v
- */
- SimpleAdapter simpleAdapter=new SimpleAdapter(this, get_data(),
- R.layout.item_simple,new String[]{
- "type","age","img"},newint[]{R.id.type_txt,R.id.age_txt,R.id.img});
- //第五步:通过setAdapter将适配器绑定到listView控件
- mshow_list.setAdapter(simpleAdapter);
- };
- /***
- * 数据源
- *
- *
- */
- private ArrayList<Map<String, Object>> get_data() {
- // 定义一个ArrayList的集合(集合中又封装一个map类型的集合)
- ArrayList<Map<String, Object>>data_list = new ArrayList<Map<String,Object>>();
- for (int i = 0; i<name.length; i++) {
- // key,value intstring map不能new map
- Map<String, Object> data_map = newHashMap<String, Object>();
- data_map.put("type", name[i]);
- data_map.put("age", i + 10+"岁");
- data_map.put("img", img[i]);
- // 将map集合添加(封装)到ArrayList集合中
- data_list.add(data_map);
- }
- // 返回ArrayList集合
- returndata_list;
- }
- }
预览效果:
3:BaseAdapter
步骤
使用BaseAdapter实现复杂的ListView的步骤:
1 首先准备好需要显示在LiseView中的数据 ——List
2 然后编写2 个XML 文件 第一个文件是ListView控件所在的布局文件 第二个文件是ListVIew中每一个item的布局文件
3 创建一个继承自BaseAdapter的类
4 为ListView绑定适配器 setAdapter(继承BaseAdapter 类的实例)
5 用传统方式来覆写适配器的getView函数和getCount 函数(从参数convertView里映射布局文件,find各个控件填充数据)
6 加入ViewHolder类(定义n个控件的声明)用convertView.setTag(viewHolder)在View和Object之间关联,此目的是节省find多次的时间。
代码:
Activity.java
- /***
- *
- *
- * BaseAdapter
- * @author Administrator
- *
- */
- public class BaseAdapterActivity extends Activity {
- private ListView mbaseshow_listview;
- private String[] arrayDate={"东方不败","天龙八部","九阴真经","东邪","南帝","北丐"};
- private int[] img = {R.drawable.l2, R.drawable.l3,R.drawable.l1, R.drawable.a5,R.drawable.a6,R.drawable.ic_launcher};
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- // TODOAuto-generated method stub
- super.onCreate(savedInstanceState);
- // 加载布局
- setContentView(R.layout.baselistview_layout);
- mbaseshow_listview =(ListView) findViewById(R.id.baseshow_listview);
- initView();
- }
- private void initView() {
- // TODOAuto-generated method stub
- MyAdapter myAdapter = new MyAdapter(this,arrayDate,img);
- //绑定适配器
- mbaseshow_listview.setAdapter(myAdapter);
- //刷新适配器
- myAdapter.notifyDataSetChanged();
- /**ListView的item点击事件
- *
- *
- *AdapterView<?> arg0:适配器
- *View arg1:表示当前item的view(视图),通过它可以获取该item中的各个组件
- *position:当前item的id,
- *arg3:表示当前的item在listview中相对位置
- *
- *
- **/
- mbaseshow_listview.setOnItemClickListener(newOnItemClickListener() {
- @Override
- public voidonItemClick(AdapterView<?> arg0, View arg1, int position,
- long arg3) {
- Toast.makeText(BaseAdapterActivity.this,"你点击了"+arrayDate[position],-1000).show();
- }
- });
- mbaseshow_listview.setOnItemLongClickListener(newOnItemLongClickListener() {
- @Override
- public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
- int position,long arg3) {
- Toast.makeText(BaseAdapterActivity.this,"执行了长按事件",0 ).show();
- return false;
- }
- });
- }
- BaseAdapter.java
- public class MyAdapter extends BaseAdapter {
- private String[] datas;
- private LayoutInflater inflater;
- private int[] imgs;
- public MyAdapter(Contextcotext, String[] datas,int[] imgs) {
- this.datas = datas;
- inflater =LayoutInflater.from(cotext);
- this.imgs=imgs;
- }
- /**
- *
- * 返回的item总数量
- *
- */
- public intgetCount() {
- return datas.length;
- }
- /**
- *
- * item的位置
- *
- */
- @Override
- public Object getItem(int position){
- // TODOAuto-generated method stub
- return datas[position];
- }
- /**
- *
- * 对应每个item里面控件的id
- *
- */
- @Override
- public longgetItemId(int position) {
- // TODOAuto-generated method stub
- return position;
- }
- @Override
- public View getView(int position,View convertView, ViewGroup parent) {
- ViewHolde viewHolde = null;
- if (null ==convertView) {
- // 实例化 ViewHolde对象
- viewHolde = newViewHolde();
- convertView = inflater.inflate(
- R.layout.item_listview,null);
- viewHolde.img=(ImageView)convertView.findViewById(R.id.img);
- viewHolde.mtype_txt =(TextView) convertView
- .findViewById(R.id.text);
- convertView.setTag(viewHolde);
- }
- else {
- viewHolde = (ViewHolde)convertView.getTag();
- }
- viewHolde.mtype_txt.setText(datas[position]);
- viewHolde.img.setImageResource(imgs[position]);
- // 返回item视图
- returnconvertView;
- }
- class ViewHolde {
- TextView mtype_txt;
- ImageView img;
- }
- }
预览效果: