android之list基本用法

1.//在ListView上输入字母，就会自动筛选出以此内容开头的Item

getListView().setTextFilterEnabled(true);

列表的显示需要三个元素：

1．ListVeiw 用来展示列表的View。

2．适配器 用来把数据映射到ListView上的中介。

3．数据 具体的将被映射的字符串，图片，或者基本组件。

根据列表的适配器类型，列表分为三种，ArrayAdapter，SimpleAdapter和SimpleCursorAdapter

其中以ArrayAdapter最为简单，只能展示一行字。SimpleAdapter有最好的扩充性，可以自定义出各种效果。

SimpleCursorAdapter可以认为是SimpleAdapter对数据库的简单结合，可以方面的把数据库的内容以列表的形式展示出来。

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ArrayAdapter用法

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xml添加ListView控件

new一个ListView

创建一个ArrayAdapter

ListView.setAdapter

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private ListView listView;

private List<String> data = new ArrayList<String>();

listView = new ListView(this);

ArrayAdapter adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_multiple_choice, getData());

listView.setAdapter(adapter);

setContentView(listView);

private List<String> getData() {

data.add("test1");

data.add("test2");

data.add("test3");

return data;

}

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SimpleCursorAdapter用法

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listView = new ListView(this);

Cursor cursor = getContentResolver().query(People.CONTENT_URI, null, null, null, null);

startManagingCursor(cursor); //将获得的Cursor对象交由Activity管理，这样Cursor的生命周期

//和Activity便能够自动同步，省去自己手动管理Cursor

ListAdapter listAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_expandable_list_item_1,

cursor,

new String[]{People.NAME},

new int[]{android.R.id.text1});

listView.setAdapter(listAdapter);

setContentView(listView);

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SimpleAdapter用法

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private ListView listView;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

listView = new ListView(this);

SimpleAdapter adapter = new SimpleAdapter(this, getData(), R.layout.vlist, new String[]{"image","text"}, new int[]{R.id.image,R.id.text});

listView.setAdapter(adapter);

setContentView(listView);

}

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("image", R.drawable.icon);

map.put("text", "item1");

list.add(map);

map = new HashMap<String, Object>();

map.put("image", R.drawable.icon);

map.put("text", "item2");

list.add(map);

return list;

}

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重写BaseAdapter，自定义item，其他和SimpleAdapter，就是adapter是自定义的

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public final class ViewHolder{

public ImageView img;

public TextView title;

public TextView info;

public Button viewBtn;

}

public class MyAdapter extends BaseAdapter{

private LayoutInflater mInflater;

public MyAdapter(Context context){

this.mInflater = LayoutInflater.from(context);

}

@Override

public int getCount() {

// TODO Auto-generated method stub

return mData.size();

}

@Override

public Object getItem(int arg0) {

// TODO Auto-generated method stub

return null;

}

@Override

public long getItemId(int arg0) {

// TODO Auto-generated method stub

return 0;

}

@Override

public View getView(int position, View convertView, ViewGroup parent) {

ViewHolder holder = null;

if (convertView == null) {

holder=new ViewHolder();

convertView = mInflater.inflate(R.layout.vlist2, null);

holder.img = (ImageView)convertView.findViewById(R.id.img);

holder.title = (TextView)convertView.findViewById(R.id.title);

holder.info = (TextView)convertView.findViewById(R.id.info);

holder.viewBtn = (Button)convertView.findViewById(R.id.view_btn);

convertView.setTag(holder);

}else {

holder = (ViewHolder)convertView.getTag();

}

holder.img.setBackgroundResource((Integer)mData.get(position).get("img"));

holder.title.setText((String)mData.get(position).get("title"));

holder.info.setText((String)mData.get(position).get("info"));

holder.viewBtn.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

showInfo();

}

});

return convertView;

}

}