Android学习 —— 多种适配器方式实现ListView

笔记摘要：

本文主要对ListView列表显示的实现进行了分析，对于列表显示，分为两个部分，第一个部分是整体布局，也就是ListView所在的布局，但ListView中的一个个横条Item布局也需要我们自己去构建，所以需要创建一个Item的布局文件，然后通过配置器来引入，当然也引入一些数据，最后为ListView设置适配器即可。适配器有多种，这里就介绍了几种不同的适配器：ArrayAdapter、SimpleAdapter、CursorAdapter、以及自定义的Adapter。

ArrayAdapter

ArrayAdapter的使用比较简单，只需为ListView设置ArrayAdapter，然后传入要显示的内容即可。由名字也可以看出，是一个类似于数组的形式，所以条目都统一了样式，

比较单一，传值也比较简便。

main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

条目显示布局：listview_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:gravity="center_vertical"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/btn_rating_star_on_normal_holo_light" />

    <TextView
        android:id="@+id/tv_content"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="我是文本"
        android:textSize="24sp" />

</LinearLayout>

MainActivity

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

public class MainActivity extends Activity {
	ListView lv; 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		lv = (ListView) findViewById(R.id.listView_id);
		lv.setAdapter(new ArrayAdapter(this,R.layout.listview_item, R.id.tv_content,new String[]{"功能1","功能2","功能3"}));
	}
}

SimpleAdatper

构造函数：

SimpleAdapter(Context context, List<? extends Map<String, ?>> data, int resource, String[] from, int[] to)

由SimpleAdapter的构造函数列表可以看出，

List<? extends Map<String, ?>>需要一个存储Map集合的List集合，来提供数据

int resource：一个布局文件来提供页面布局

From：A list of column names that will be added to the Map associated with each item.，需要适配数据的列名，其与Map集合的键相对应。

To : The views that should display column in the "from" parameter. These should all be TextViews. 与From相对应的TextView的资源ID

整体布局文件Main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

     <TextView
        
        android:id="@+id/info_textView" 
        android:text="产品详细信息"
        android:textSize="25sp"
        android:gravity="center"
        android:layout_width="match_parent"
    	android:layout_height="wrap_content"
        />
    <ListView
        android:layout_below="@id/info_textView"
        android:id="@+id/listView_id" 
        android:layout_width="match_parent"
    	android:layout_height="match_parent"
        ></ListView>
</RelativeLayout>

条目的布局文件listView_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="match_parent"
    android:orientation="horizontal" >
    
    <TextView
        android:id="@+id/model_textView" 
        android:text="型号"
        android:textSize="20sp"
        android:gravity="center_horizontal"
        android:layout_weight="1"
        android:layout_width="match_parent"
    	android:layout_height="match_parent"
        />
    <TextView 
        android:text="颜色"
        android:textSize="20sp"
        android:gravity="center_horizontal"
        android:layout_weight="1"
        android:id="@+id/color_textView" 
        android:layout_width="match_parent"
    	android:layout_height="match_parent"
        />
    <TextView 
        android:text="大小"
        android:textSize="20sp"
        android:layout_weight="1"
        android:gravity="center_horizontal"
        android:id="@+id/size_textView" 
        android:layout_width="match_parent"
    	android:layout_height="match_parent"
        />

</LinearLayout>

MainActivity

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.view.Menu;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class MainActivity extends Activity {
	private ListView listView;
	private List<Map<String,String>> data ;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		listView = (ListView) findViewById(R.id.listView_id);
		
		
		Map<String,String> itemdata1 = new HashMap<String,String>();
		itemdata1.put("型号","复古");
		itemdata1.put("颜色","浅灰");
		itemdata1.put("大小","Large");
		
		Map<String,String> itemdata2 = new HashMap<String,String>();
		itemdata2.put("型号","时尚");
		itemdata2.put("颜色","紫金");
		itemdata2.put("大小","small");
		
		data = new ArrayList<Map<String,String>>();
		data.add(itemdata1);
		data.add(itemdata2);
		
		//SimpleAdapter(Context context, List<? extends Map<String,?>> data, int resource, String[] from, int[] to)
				//context,上下文 
				//List<? extends Map<String, ?>> data,提供要显示的数据
				//int resource,一个布局文件来提供页面布局
				//String[] from, 需要适配数据的列名，其与Map集合的键相对应。
				//int[] to 与from相对应的显示视图，必须都是TextView，通过R.id.TextView来引入
		listView.setAdapter(new SimpleAdapter(this, data, R.layout.listview_item, new String[]{"颜色","型号","大小"}, 
				new int[]{R.id.model_textView,R.id.color_textView,R.id.size_textView}));
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.activity_main, menu);
		return true;
	}

}

CursorAdapter

注意：

在使用CursorAdapter为Listview适配的时候，Sqlite标准要求cursor必须有一个属性 "_id"，否则就无法使用

在使用SimpleCursorAdapter时，有一个相同的方法已经过时，对于这样的处理，为了向下兼容，我们可以将低版本和高版本的方法都提供出去，只需对用户的版本进行判断调用响应的方法即可

总体布局文件

<LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <LinearLayout 
        android:layout_width="match_parent"
    	android:layout_height="wrap_content"
    	android:orientation="horizontal"
        >
    <TextView
	    android:text="姓名"
	    android:textSize="23sp"
	    android:id="@+id/name_textView"
	    android:layout_weight="1"
	    android:layout_gravity="center_horizontal"
	    android:gravity="center"
	    android:layout_width="match_parent"
    	android:layout_height="wrap_content"
	    />
	<TextView
	    android:text="电话"
	    android:textSize="23sp"
	    android:id="@+id/phone_textView"
	    android:layout_weight="1"
	    android:gravity="center"
	    android:layout_gravity="center_horizontal"
	    android:layout_width="match_parent"
    	android:layout_height="wrap_content"
	    />
	<TextView
	    android:text="收入"
	    android:textSize="23sp"
	    android:id="@+id/money_textView"
	    android:layout_weight="1"
	    android:gravity="center"
	    android:layout_gravity="center_horizontal"
	    android:layout_width="match_parent"
    	android:layout_height="wrap_content"
	    />
    </LinearLayout>
    
    <ListView 
        android:id="@+id/listView_id"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        ></ListView>
  
  </LinearLayout>

条目布局文件

<?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="match_parent"
    android:orientation="horizontal" >
    
	<TextView
	    android:text="姓名"
	    android:id="@+id/name_textView"
	    android:textSize="20sp"
	    android:layout_weight="1"
	    android:layout_gravity="center_horizontal"
	    android:gravity="center"
	    android:layout_width="match_parent"
    	android:layout_height="wrap_content"
	    />
	<TextView
	    android:text="电话"
	    android:id="@+id/phone_textView"
	    android:textSize="20sp"
	    android:layout_weight="1"
	    android:gravity="center"
	    android:layout_gravity="center_horizontal"
	    android:layout_width="match_parent"
    	android:layout_height="wrap_content"
	    />
	<TextView
	    android:text="收入"
	    android:id="@+id/money_textView"
	    android:textSize="20sp"
	    android:layout_weight="1"
	    android:gravity="center"
	    android:layout_gravity="center_horizontal"
	    android:layout_width="match_parent"
    	android:layout_height="wrap_content"
	    />
</LinearLayout>

MainActivity

import android.app.Activity;
import android.database.Cursor;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter;
import android.util.Log;
import android.webkit.WebChromeClient.CustomViewCallback;
import android.widget.LinearLayout;
import android.widget.ListView;

import com.itheima.db.dao.PersonDao2;

public class MainActivity extends Activity {
	private static final String TAG = "MainActivity";
	private ListView listView;

	@SuppressWarnings("deprecation")
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		listView = (ListView) findViewById(R.id.listView_id);
		
		/*PersonDBOpenHelper helper = new PersonDBOpenHelper(this);
		helper.getWritableDatabase();*/
		
		PersonDao dao = new PersonDao(this);
		Cursor cursor = dao.findAllCursor();//查询所有的记录并返回Cursor
		while(cursor.moveToNext()){
			int id = cursor.getInt(cursor.getColumnIndex("_id"));
			String name = cursor.getString(cursor.getColumnIndex("name"));
			String phone = cursor.getString(cursor.getColumnIndex("phone"));
			int money = cursor.getInt(cursor.getColumnIndex("money"));
			Log.i(TAG,id+" name: "+name+" phone: "+phone+" money: "+money);
		}
		
		
		//(Context context, int layout, Cursor c, String[] from, int[] to)
		if (Build.VERSION.SDK_INT >= 11) {
			// api 11以上才可以运行
			listView.setAdapter(new SimpleCursorAdapter(
					this, 
					R.layout.list_item, 
					cursor,
					new String[] { "name", "phone", "money" }, 
					new int[] {R.id.name_textView, R.id.phone_textView, R.id.money_textView }, 
					0));
			Log.i(TAG,"我是高版本api");
		} else {

			// api 11 以下运行
			listView.setAdapter(new SimpleCursorAdapter(this, 
					R.layout.list_item, 
					cursor,
					new String[] { "name", "phone", "money" }, 
					new int[] {R.id.name_textView, R.id.phone_textView, R.id.money_textView }));
			
			Log.i(TAG,"我是低版本api");
		}
	
	}
}

自定义Adapter：继承BaseAdapter

整体布局文件：Main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
	
	<LinearLayout 
	    android:layout_width="match_parent"
	    android:layout_height="wrap_content">
	    
    <TextView
        android:text="ID" 
        android:layout_weight="1"
        android:textSize="18sp"
        android:gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
    <TextView
        android:text="姓名" 
        android:layout_weight="1"
        android:textSize="18sp"
        android:gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
    <TextView
        android:text="电话" 
        android:layout_weight="1"
        android:textSize="18sp"
        android:gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
    <TextView
        android:text="收入" 
        android:textSize="18sp"
        android:layout_weight="1"
        android:gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
    </LinearLayout>

		<ListView
	    android:id="@+id/lv"
	    android:layout_width="wrap_content"
        android:layout_height="wrap_content"
	    />
	
</LinearLayout>

Item布局文件

<?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="match_parent"
    android:orientation="horizontal" >
    
	<TextView
	    android:id="@+id/id_TextView"
	    android:text="ID" 
	    android:gravity="center_horizontal"
	    android:layout_width="0dip"
	    android:layout_height="match_parent"
	    android:layout_weight="1"
		android:textSize="16sp"
	    />

	<TextView
	    android:id="@+id/name_TextView" 
	    android:text="姓名"
	    android:layout_weight="1"
	    android:gravity="center_horizontal"
		android:layout_width="0dip"
	    android:layout_height="match_parent"
	    android:textSize="16sp"
	    />
	<TextView
	    android:id="@+id/phone_TextView" 
	    android:text="电话"
	    android:layout_weight="1"
	    android:gravity="center_horizontal"
		android:layout_width="0dip"
	    android:layout_height="match_parent"
	    android:textSize="16sp"
	    />
	<TextView
	    android:id="@+id/amount_TextView" 
	    android:text="收入"
	    android:layout_weight="1"
	    android:gravity="center_horizontal"
		android:layout_width="0dip"
	    android:layout_height="match_parent"
	    android:textSize="16sp"
	    />
</LinearLayout>

MainActivity

public class MainActivity extends Activity {
	private static final String TAG = "MainActivity";
	private List<Person> persons ;
	private PersonDao dao;
	private ListView lv ;
	ListAdapter adapter;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		lv = (ListView) findViewById(R.id.lv);
		dao = new PersonDao(this);
		persons = dao.findAll();
		
		
		adapter = new ListAdapter();
		Log.i(TAG,adapter.getCount()+"");
		lv.setAdapter(adapter);//为ListView 设置适配器，适配器中已经将数据填充到了布局中
		
		//为ListView设置点击事件
		lv.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> parent, View view,
					int position, long id) {
				Person person = persons.get(position);
				String name = person.getName();
				int personid = person.getId();
				//Toast.makeText(MainActivity.this, personid, 1).show();
				Toast.makeText(MainActivity.this, "id:"+personid, 1).show();
			}
		});
		
		//为ListView设置长按监听：删除一条数据
		lv.setOnItemLongClickListener(new OnItemLongClickListener() {

			@Override
			public boolean onItemLongClick(AdapterView<?> parent, View view,
					int position, long id) {
				Person person = persons.get(position);
				int personid = person.getId();
				dao.delete(personid);//从数据库中将数据删除
				persons.remove(position);//从适配器中删除
				adapter.notifyDataSetChanged();//通知数据适配器 更新界面
				
				return true;//false 当前的事件 不会被消费掉,继续执行，OnItemClickListener会Toaster
							 //true 当前事件执行到这里 就终止了，后面的不再执行，
								  //比如setOnItemClickListener的Toaster就不执行
			}});
			
	}

自定义的Adapter类：继承BaseAdapter

	private final class ListAdapter extends BaseAdapter{

		@Override
		public int getCount() {
			return persons.size();
		}

		@Override
		public Object getItem(int position) {
			return null;
		}

		@Override
		public long getItemId(int position) {
			return 0;
		}
		
		//返回当前位置对应的view对象，显示内容
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			//position代表位置
			
			//通过View关联自定义Item布局，进行填充
			View view = View.inflate(MainActivity.this, R.layout.list_item, null);
			
			//获取指定位置的对象
			Person person = persons.get(position);
			
			//获取要显示的组件,注意findViewById的调用对象是上面填充了Item的布局的对象View
			TextView id_TextView = (TextView)view.findViewById(R.id.id_TextView);
			TextView name_TextView = (TextView)view.findViewById(R.id.name_TextView);
			TextView amount_TextView =(TextView)view.findViewById(R.id.amount_TextView);
			TextView phone_TextView =(TextView)view.findViewById(R.id.phone_TextView);
			
			id_TextView.setText(person.getId()+"");
			name_TextView.setText(person.getName());
			amount_TextView.setText(person.getAmount()+"");
			phone_TextView.setText(person.getPhone());
			
			return view;
		}
	}
}

工具类：查询所有的记录，这里省略了数据库

public List<Person> findAll(){
		List<Person> persons = new ArrayList<Person>();
		SQLiteDatabase db = helper.getReadableDatabase();
		//query(String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy, String limit)

		Cursor cursor = db.query("person", new String[]{"id","name","phone","amount"}, null, null, null, null, null, null);
		while(cursor.moveToNext()){
			int id = cursor.getInt(cursor.getColumnIndex("id"));
			String name = cursor.getString(cursor.getColumnIndex("name"));
			String phone = cursor.getString(cursor.getColumnIndex("phone"));
			String amount = cursor.getString(cursor.getColumnIndex("amount"));
			persons.add(new Person(id,name,phone,Float.valueOf(amount)));
		}
		cursor.close();//关闭游标
		db.close();//关闭数据库
		return persons;
	}

posted @ 2013-04-19 22:47 积小流，成江海阅读(307) 评论(0) 编辑收藏举报

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积小流，成江海

Android学习 —— 多种适配器方式实现ListView

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