Android中常用的适配器

1.ArrayAdapter     数组适配器，该适配使用非常简单，但是也有一定的局限性，列表只能是TextView，如下所示

Java代码

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;


public class MainActivity extends Activity {
private ListView listView;
private String[] letters = { "A", "B", "C", "D", "E", "F", "G","H",
"I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T",
"U", "V","W", "X", "Y", "Z" };


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
/**
* 匿名内部类设置适配器 context:上下文,即代表当前的Activity.
* textViewResourceId:列表的布局,本例采用Android自带的布局,当然读者也可以自定义布局
* ,但要注意的是在选择布局的方式时要选择TextView objects:数据源，可以是多种类型,如数组,集合
*/
listView.setAdapter(new ArrayAdapter(MainActivity.this,
android.R.layout.simple_list_item_1, citys));
}
}

布局：

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >


            android:id="@+id/listView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >
   

2.SimpleAdapter       简单适配器，不要看名字简单，其实并不简单，该适配器的功能比较强大，如下例所示

Java代码

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.SimpleAdapter;


public class MainActivity extends Activity {
private ListView listView;
private String[] letters = { "A", "B", "C", "D", "E", "F", "G", "H", "I",
"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
"W", "X", "Y", "Z" };
private String[] names = { "a", "b", "c", "d", "e", "f", "g", "h", "i",
"j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
"w", "x", "y", "z" };
private List> lists;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
lists = new ArrayList>();
for (int i = 0; i < letters.length; i++) {
Map map = new HashMap();
map.put("letter", letters[i]);
map.put("name", names[i]);
lists.add(map);
}
/**
* 匿名内部类设置适配器 
* context:上下文,即代表当前的Activity.
* data:数据源(List集合)
* resource:列表的布局.
* from:字符串数组类型,即所要map所对应的key 
* to:列表的ID
*/
listView.setAdapter(new SimpleAdapter(MainActivity.this, lists,
R.layout.list, new String[] { "letter", "name" }, new int[] {
R.id.letters, R.id.names }));
}
}

布局文件：

list

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >


            android:id="@+id/letters"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />


            android:id="@+id/names"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp" />

activtiy_main

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >


            android:id="@+id/listView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >
   

3.BaseAdapter适配器，该适配器非常灵活，运用非常广，如下例所示

Java代码

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;


public class MainActivity extends Activity {
private ListView listView;
private String[] letters = { "A", "B", "C", "D", "E", "F", "G", "H", "I",
"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
"W", "X", "Y", "Z" };


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
listView.setAdapter(new MyBaseAdapter());
}


class MyBaseAdapter extends BaseAdapter {
// 列表的数量
@Override
public int getCount() {
// TODO Auto-generated method stub
return letters.length;
}


// 返回当前的列表项
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return letters[position];
}


// 返回当前的列表项所在的索引
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}


// 得到并显示列表项
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
if (convertView == null) {
LayoutInflater inflater = getLayoutInflater();
convertView = inflater.inflate(R.layout.list, parent, false);
}
TextView letter = (TextView) convertView.findViewById(R.id.letter);
letter.setText(letters[position]);
return convertView;
}


}
}

list

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >


            android:id="@+id/letter"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

activity_main

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >


            android:id="@+id/listView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >