Adapter详解

动态添加数据适配器adapter

Adapter是适配器，许多UI组件需要搭配Adapter来显示界面，例如Spinner与ListView,另外当我们需要动态的添加数据给UI组件时就需要Adapter了。

我们来介绍几个常见的Adapter：

ArrayAdapter<T>(comman)
SimpleAdapter extends Baseadapter(comman)
******************************************************************************

这两个适配器非常常见，也非常有用，通常传输的数据可以是ArrayList<>封装的数据。

示例如下：ArrayAdapter

[java]
private String[] string={"china","america","易做图"};
List list=new ArrayList<String>();
for(int i=0;i<string.length;i++)
{
list.add(string[i]);
}
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.易做图_spinner_item,list);

private String[] string={"china","america","易做图"};
List list=new ArrayList<String>();
for(int i=0;i<string.length;i++)
{
list.add(string[i]);
}
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.易做图_spinner_item,list);首先我们定义封装数据，然后再定义Adapter，最后调用setAdapter（）方法。

ArrayAdapter有三个参数，第一个参数为Activity.this,第三个参数为动态添加给adapter的数据
对于第二个数据：
R.layout.易做图_spinner_item:意思是将数据传给一个简单地TextView组件

示例：SimpleAdapter

[java]
public class SimpleAdapter extends Activity{
private String[] names =new String[]{"nick","lebron","kobe","kevin"};
private int[] imgsIds[] =new Int[] {R.drawable.1,R.drawable.2,R.drawable.3,R.drawable.4};
@Override
public void onCreate(Bundle savedInsatnceState)
{
super.onCreate(savedInsatnceState);
setTitle("易做图adapter");
setContentView(R.layout.main);
List<Map><String,Object> list=new ArrayList<Map><String,Object>（）;//创建动态数组ArrayList
for(int i=0;i<names.length;i++){
Map<String,Object> map=new HashMap=<String,Object>;
map.put("name",names[i]);
map.put("headerImg",imgsIds[i]);
list.add(map);
}
SimpleAdapter adapter=new SimpleAdaper(this,list,R.layout.main,new String[]{"name","headerImg"},new int[]{R.id.name,R.id.headerImg});
ListView list=(ListView)findViewById(R.id.mylist);
list.setAdaper(adapter);
}
}

public class SimpleAdapter extends Activity{
private String[] names =new String[]{"nick","lebron","kobe","kevin"};
private int[] imgsIds[] =new Int[] {R.drawable.1,R.drawable.2,R.drawable.3,R.drawable.4};
@Override
public void onCreate(Bundle savedInsatnceState)
{
super.onCreate(savedInsatnceState);
setTitle("易做图adapter");
setContentView(R.layout.main);
List<Map><String,Object> list=new ArrayList<Map><String,Object>（）;//创建动态数组ArrayList
for(int i=0;i<names.length;i++){
Map<String,Object> map=new HashMap=<String,Object>;
map.put("name",names[i]);
map.put("headerImg",imgsIds[i]);
list.add(map);
}
SimpleAdapter adapter=new SimpleAdaper(this,list,R.layout.main,new String[]{"name","headerImg"},new int[]{R.id.name,R.id.headerImg});
ListView list=(ListView)findViewById(R.id.mylist);
list.setAdaper(adapter);
}
}

接下来我们介绍另一个常用的Adapter：BaseAdapter
BaseAdapter implements SpinnerAdapter implements ListViewAdapter（可用于ListView和Spinner）

示例：

[java]
public MyListView extensds Activity{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInsatnceState);
mDate=getDate();
MyAdapter myadapter=new MyAdapter(this);
ListView list=(ListView)findById(R.id.myList);
setAdapter(myadapter);
}
private List<Map<String, Object>> getData() {
            List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("title", "G1");
            map.put("info", "google 1");
            map.put("img", R.drawable.i1);
            list.add(map);
     //添加第二个Map数据
            map = new HashMap<String, Object>();
            map.put("title", "G2");
            map.put("info", "google 2");
            map.put("img", R.drawable.i2);
            list.add(map);
     //添加第三个Map数据
            map = new HashMap<String, Object>();
            map.put("title", "G3");
            map.put("info", "google 3");
            map.put("img", R.drawable.i3);
            list.add(map);
        return list; //返回List数据
    }
@verride
protected void onListItemClicked(ListView 1,View v,int position,long id){
Log.v("MyListView4_click",(String)mData.get(position).get("title"));
    }
public void showInfo(){
    new AlertDiolog.Builder(this)
    .setTitle("MyListView")
    .setMessage(Introduce)
    .setPositiveButton("Ensure",new DialogInte易做图ce.OnClickListener()
    {@Override
    public void onClick(DialogInte易做图ce dialog,int which){} }).show();
    }
}
private final class ViewHolder{
public ImageView img;
public TextView title;
public TextView info;
public Button viewBu;
}
public class MyAdapter extens BaseAdapter{
private LayoutInlfater myInflater;
public MyAdapter(Context context){
this.myInflater=LayoutInflater.from(context);
}
@Override
public int getCount(){
&n

补充：软件开发 , Java ,