[android] 练习使用ListView（一）

练习使用ListView,BaseAdapter，先展示文字的，再练习图片的

MainActivity.java

package com.android.test;

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

public class MainActivity extends Activity {
    private ListView lv_images;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lv_images = (ListView) findViewById(R.id.lv_images);
        ListAdapter adapter = new ImageAdapter();
        lv_images.setAdapter(adapter);
    }
    /**
     * 适配器
     * @author taoshihan
     *
     */
    class ImageAdapter extends BaseAdapter {

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            String url=(String) getItem(position);
            View view;
            if(convertView!=null){
                view=convertView;
            }else{
                view=View.inflate(getApplicationContext(), R.layout.image_item, null);
            }
            TextView tv_image=(TextView) view.findViewById(R.id.tv_image);
            
            tv_image.setText(url);
            return view;
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return Images.IMAGE_URLS.length;
        }

        @Override
        public Object getItem(int position) {
            return Images.IMAGE_URLS[position];
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return position;
        }

    }
    static class Images{
        public final static String[] IMAGE_URLS = new String[]{
            "http://img.my.csdn.net/uploads/201508/05/1438760758_3497.jpg",    
            "http://img.my.csdn.net/uploads/201508/05/1438760758_6667.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760757_3588.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760756_3304.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760755_6715.jpeg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760726_5120.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760726_8364.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760725_4031.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760724_9463.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760724_2371.jpg",  
            "http://img.my.csdn.net/uploads/201508/05/1438760707_4653.jpg"
        };
    }
}

activity_main.xml

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

image_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/tv_image"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>