Android ListView 列表视图

列表显示的三个元素

ListView : 用来显示列表的View

Adapter : 适配器 用来把数据映射到ListView 上的中介

Data: 数据 将被映射的字符串,图片或者基本组件等资源

根据列表的适配器类型 可分为三种: ArrayAdapter,  SimpleAdapter ,SimpleCursorAdapter  .

ArrayAdapter  最简单 ,只能显示一行字

SimpleAdapter 扩充性好,可以自定义各种效果 ,

SimpleCursorAdapter  可以认为是对数据库的简单结合,可以把数据库的内容以列表的形式显示出来.

ArrayAdapter适配器  简单实例:

package com.app.listviewtest;

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

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {
	//创建ListView 对象
	private ListView mListView ;
	//添加数据
	List<Object> data;
	private List getData(){
		data = new ArrayList<Object>();
		data.add("Java");
		data.add("android");
		data.add("c");
		data.add("c++");
		return data;
	}
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		mListView = new  ListView(this);//获得组件
		//设置适配器
		mListView.setAdapter(new ArrayAdapter<Object>(this,android.R.layout.simple_expandable_list_item_1,getData()));
		//设置布局 显示listView
		setContentView(mListView);

		mListView.setOnItemClickListener( new AdapterView.OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> parent, View view,
					int position, long id) {
				String text =data.get(position).toString();
				switch (position) {

					case 0 :
						 Toast.makeText(getApplicationContext(),text+"被点击" , 0).show();
						break;
					case 1 :
						Toast.makeText(getApplicationContext(),text+"被点击" , 0).show();
						break;
					case 2 :
						Toast.makeText(getApplicationContext(),text+"被点击" , 0).show();
						break;
					case 3 :
						Toast.makeText(getApplicationContext(),text+"被点击" , 0).show();
						break;

					default :
						break;
				}
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

 SimpleAdapter 的简单使用:

布局文件:

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

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <ImageView
                android:id="@+id/ImageView1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
              />
            <TextView
                android:id="@+id/TextView1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                />
        </LinearLayout>
</LinearLayout>

Java文件:

package com.app.listviewtest;

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

import android.app.ListActivity;
import android.os.Bundle;
import android.view.Window;
import android.widget.SimpleAdapter;

public class simpleAdapterActivity extends ListActivity {
	//数据源
	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("ImageView1", R.drawable.ic_launcher);
		map.put("TextView1", "图片一");
		list.add(map);
		map = new HashMap<String, Object>();
		map.put("ImageView1", R.drawable.ic_launcher);
		map.put("TextView1", "图片二");
		list.add(map);
		map = new HashMap<String, Object>();
		map.put("ImageView1", R.drawable.ic_launcher);
		map.put("TextView1", "图片3");
		list.add(map);
		map = new HashMap<String, Object>();
		map.put("ImageView1", R.drawable.ic_launcher);
		map.put("TextView1", "图片4");
		list.add(map);
		return list;
	}
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		//隐藏标题
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		//设置 适配器  (上下文,数据,模板的资源ID,组件对应的资源,xml布局文件中组件的id)
		//public SimpleAdapter(Context context, List<? extends Map<String, ?>> data,int resource, String[] from, int[] to) {}
		SimpleAdapter adapter = new SimpleAdapter(getApplicationContext(), getData(),
				R.layout.simpleadapter_activity,new String[]{"ImageView1","TextView1"},
				new int[] {R.id.ImageView1,R.id.TextView1});
		setListAdapter(adapter);
	}
}