Android 用的最多的，也最難用的應(yīng)該就是 ListView 了，下面我們研究一下它的用法。

Android 用的最多的，也最難用的應(yīng)該就是 ListView 了，下面我們研究一下它的用法。

一、最簡(jiǎn)單的 ListView

我們簡(jiǎn)單介紹一下 ListView 的最簡(jiǎn)單用法，不使用布局文件：

package org.lxh.demo;

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

public class MainActivity extends Activity {
    private String[] arrays = { "Sunday", "Monday", "Tuesday", "Wednesday",
            "Thursday", "Friday", "Saturday" };
    private ListView listView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        listView = new ListView(this);
        listView.setAdapter(new ArrayAdapter<String>(this,
                android.R.layout.simple_expandable_list_item_1, arrays));//利用ArrayAdapter對(duì)數(shù)據(jù)進(jìn)行包裝
        super.setContentView(listView);//將ListView設(shè)置為顯示界面
    }

}

運(yùn)行實(shí)例如下：

http://wiki.jikexueyuan.com/project/android-in-action/images/10.png" alt="" />

二、結(jié)合 ArrayAdapter 實(shí)現(xiàn)較復(fù)雜的 ListView

1.main.xml 代碼：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <ListView
        android:id="@+id/list_view"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" /></LinearLayout>

2.fruit_item.xml 代碼：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <ImageView
        android:id="@+id/fruit_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/fruit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginLeft="10sp" />
</LinearLayout>

3.Fruit.java 代碼如下：

package org.lxh.demo;

public class Fruit {
    private String name;
    private int imageId;

    public Fruit(String name, int imageId) {
        this.name = name;
        this.imageId = imageId;
    }

    public String getName() {
        return name;
    }

    public int getImageId() {
        return imageId;
    }
}

4.集成 ArrayAdapter 的 FruitAdapter.java 代碼如下：

package org.lxh.demo;

import java.util.List;

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

public class FruitAdapter extends ArrayAdapter<Fruit> {
    private int resourceId;

    public FruitAdapter(Context context, int textViewResourceId,
            List<Fruit> objects) {
        super(context, textViewResourceId, objects);
        resourceId = textViewResourceId;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        Fruit fruit = getItem(position);
        View view;
        ViewHolder viewHolder;
        if (convertView == null) {
            view = LayoutInflater.from(getContext()).inflate(resourceId, null);
            viewHolder = new ViewHolder();
            viewHolder.fruitImage = (ImageView) view
                    .findViewById(R.id.fruit_image);
            viewHolder.fruitName = (TextView) view
                    .findViewById(R.id.fruit_name);
            view.setTag(viewHolder);
        } else {
            view = convertView;
            viewHolder = (ViewHolder) view.getTag();
        }

        viewHolder.fruitImage.setImageResource(fruit.getImageId());
        viewHolder.fruitName.setText(fruit.getName());
        return view;

    }

    class ViewHolder {
        ImageView fruitImage;
        TextView fruitName;
    }

}

5.MainActivity.java 代碼如下：

package org.lxh.demo;

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

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

public class Hello extends Activity {
    private List<Fruit> fruitList = new ArrayList<Fruit>();

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); // 生命周期方法
        super.setContentView(R.layout.main); // 設(shè)置要使用的布局管理器
        initFruits();
        FruitAdapter adapter = new FruitAdapter(Hello.this,
                R.layout.fruit_item, fruitList);
        ListView listView = (ListView) findViewById(R.id.list_view);
        listView.setAdapter(adapter);

    }

    private void initFruits() {
        Fruit appleFruit = new Fruit("Apple", R.drawable.apple_pic);
        fruitList.add(appleFruit);
        Fruit bananaFruit = new Fruit("Banana", R.drawable.banana_pic);
        fruitList.add(bananaFruit);
        Fruit orangeFruit = new Fruit("Orange", R.drawable.orange_pic);
        fruitList.add(orangeFruit);
        Fruit waterFruit = new Fruit("Apple", R.drawable.watermelon_pic);
        fruitList.add(waterFruit);

    }
}

運(yùn)行實(shí)例如下：

http://wiki.jikexueyuan.com/project/android-in-action/images/11.png" alt="" />

三、結(jié)合上下文菜單實(shí)現(xiàn)單項(xiàng)的刪除

修改 MainActivity.java 程序如下：

package org.lxh.demo;

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

import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.ListView;
import android.widget.AdapterView.AdapterContextMenuInfo;

public class Hello extends Activity {
    private List<Fruit> fruitList = new ArrayList<Fruit>();
    FruitAdapter adapter;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); // 生命周期方法
        super.setContentView(R.layout.main); // 設(shè)置要使用的布局管理器
        initFruits();
        adapter = new FruitAdapter(Hello.this, R.layout.fruit_item, fruitList);
        ListView listView = (ListView) findViewById(R.id.list_view);
        listView.setAdapter(adapter);
        super.registerForContextMenu(listView);//注冊(cè)上下文菜單

    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,// 創(chuàng)建菜單項(xiàng)
            ContextMenuInfo menuInfo) {

        super.onCreateContextMenu(menu, v, menuInfo);
        menu.setHeaderTitle("選擇操作");
        menu.add(Menu.NONE, Menu.FIRST + 1, 1, "刪除");
        menu.add(Menu.NONE, Menu.FIRST + 2, 2, "取消");
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {// 選擇監(jiān)聽(tīng)
        AdapterContextMenuInfo acmiRef = (AdapterContextMenuInfo) item
                .getMenuInfo();// 用來(lái)獲取item信息哎，重要
        int removeIndex = acmiRef.position;
        switch (item.getItemId()) {
        case Menu.FIRST + 1:
            fruitList.remove(removeIndex);
            adapter.notifyDataSetChanged();// 刪除后刷新ListView

            break;
        case Menu.FIRST + 2:

            break;

        default:
            break;
        }
        return false;
    }

    private void initFruits() {
        Fruit appleFruit = new Fruit("Apple", R.drawable.apple_pic);
        fruitList.add(appleFruit);
        Fruit bananaFruit = new Fruit("Banana", R.drawable.banana_pic);
        fruitList.add(bananaFruit);
        Fruit orangeFruit = new Fruit("Orange", R.drawable.orange_pic);
        fruitList.add(orangeFruit);
        Fruit waterFruit = new Fruit("Apple", R.drawable.watermelon_pic);
        fruitList.add(waterFruit);

    }
}

運(yùn)行實(shí)例：

http://wiki.jikexueyuan.com/project/android-in-action/images/12.png" alt="" />

選擇刪除后：

http://wiki.jikexueyuan.com/project/android-in-action/images/13.png" alt="" />

總結(jié)

1. super.registerForContextMenu(listView);//注冊(cè)上下文菜單
2. adapter.notifyDataSetChanged();// 刪除后刷新 ListView
3. AdapterContextMenuInfo acmiRef = (AdapterContextMenuInfo) item.getMenuInfo();// 用來(lái)獲取當(dāng)前 item 信息，重要 int removeIndex = acmiRef.position;//獲取點(diǎn)擊位置的坐標(biāo)