自定义ListView adapter适配器

转自：http://hilary3113.iteye.com/blog/998352

listview加载adapter过程是这样的．

１　先判断adapter 有多少数据项，根据这个数据确定有多少item. 
２　确定每个item里加载哪个View.　
３　把View里加载要显示的数据．

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:text="123424312423142134" />
    <ListView android:id="@+id/list" android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

listView布局文件：item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView android:id="@+id/name" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView android:id="@+id/sex" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView android:id="@+id/age" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

定义一个类，用来传值 People.java

public class People {
    public String name;
    public String sex;
    public String age;
}

定义适配器 MyAdapter.java

package com.action;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

/**
 *@Author: hilary
 *@Date: 2011-4-11
 **/
public class MyAdapter extends BaseAdapter {
    private List<People> list = new ArrayList<People>();
//  private People people = new People();
    private Context context;

    public MyAdapter(Context context){
        this.context = context;
    }
    //适配器根据getCount()函数来确定要加载多少项
    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int paramInt) {

        return list.get(paramInt);
    }

    @Override
    public long getItemId(int paramInt) {
        return paramInt;
    }
    /*
     * 当列表里的每一项显示到界面时，都会调用这个方法一次，并返回一个view 所以方法里面尽量要简单，不要做没必要的动作(non-Javadoc)
     * 我这里为了大家好理解，没有做优化
     */
    @Override
    public View getView(int paramInt, View paramView, ViewGroup paramViewGroup) {
        //得到列表样式的view对象
        paramView=LayoutInflater.from(context).inflate(R.layout.item, null);
        //通过view来得到Item中的每个控件的操作权
        TextView name = (TextView)paramView.findViewById(R.id.name);
        TextView sex = (TextView)paramView.findViewById(R.id.sex);
        TextView age = (TextView)paramView.findViewById(R.id.age);
        //获得list里面的第paramInt个对象，并把值赋给每个控件
        People people = list.get(paramInt);
        name.setText(people.name);
        sex.setText(people.sex);
        age.setText(people.age);
        //把一项返回，加载这个View
        return paramView;
    }
    public void addList(People people){
        list.add(people);
    }
}

主类

package com.action;

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

public class Tab extends Activity {
    MyAdapter adapter ;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        System.out.println("*********Tab");
        ListView listView =(ListView) findViewById(R.id.list);
        adapter = new MyAdapter(this);
        setPeople();
        listView.setAdapter(adapter);
    }
    public void setPeople(){
        People people;
        for(int i=1;i<5;i++){
            people = new People();
            people.name="张三";
            people.sex = "男";
            people.age ="22";
            adapter.addList(people);
        }
    }
}