Android ListView例子详解

三种实现方法，由浅入深。这中间要注意Adapter的用法，其实你要是看过Android的文档，你会发现有很多Adapter，

如果你还不太清楚适配器模式，可以先补补这方面的知识。在实际工作中，设计模式是个很好的帮手。

两个layout文件：

main.xml

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

listview.xml

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/linerlayout1"    android:orientation="vertical"    android:layout_height="fill_parent"    android:layout_width="fill_parent"    >       <TextView          android:id="@+id/person_name"          android:textSize="23sp"          android:layout_width="wrap_content"          android:layout_height="wrap_content"       />       <TextView          android:id="@+id/person_age"          android:layout_width="wrap_content"          android:layout_height="wrap_content"      />      <TextView          android:id="@+id/person_email"          android:layout_width="wrap_content"          android:layout_height="wrap_content"      />      <TextView          android:id="@+id/person_address"          android:layout_width="wrap_content"          android:layout_height="wrap_content"      />  </LinearLayout>  

Activity:LincListViewActivity.java

package com.linc.listview;import android.app.Activity;import android.os.Bundle;import android.widget.ArrayAdapter;import android.widget.ListView;public class LincListViewActivity extends Activity {private final static String[] data = {"张飞","张辽","张角","张三丰","张牙舞爪","张灯结彩","张唑啉","张大民"};//创建数据源.      Zhang[] data2 = new Zhang[]{          new Zhang("张飞",38,"[e-mail]","燕山"),          new Zhang("张辽",36,"[e-mail]","雁门"),          new Zhang("张角",51,"[e-mail]","钜鹿"),          new Zhang("张三丰",200,"[e-mail]","辽东"),          new Zhang("张牙舞爪",25,"[e-mail]","冀州"),        new Zhang("张灯结彩",25,"[e-mail]","冀州") ,        new Zhang("张唑啉",25,"[e-mail]","冀州") ,        new Zhang("张大民",25,"[e-mail]","冀州") ,        new Zhang("张牙舞爪",25,"[e-mail]","冀州")      };      /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                ListView listview = (ListView)findViewById(R.id.listview);        /*         * 第一种：普通字符串         */        ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(this,         android.R.layout.simple_list_item_1,data);                /*         * 第二种：文艺类对象         */        ArrayAdapter<Zhang> adapter2 = new ArrayAdapter<Zhang>(this,         android.R.layout.simple_list_item_1,data2);                /*         * 第三种：自定义适配器         */        ListAdapter adapter3 = new ListAdapter(this, R.layout.listview,data2) ;//okay, the resource id is passed.                listview.setAdapter(adapter3);    }}

数据类对象：Zhang.java

package com.linc.listview;public class Zhang {           private String name;      private int age;      private String email;      private String address;      public String getName() {return name;}public int getAge() {return age;}public String getEmail() {return email;}public String getAddress() {return address;}       public Zhang(String name, int age, String email, String address) {          super();          this.name = name;          this.age = age;          this.email = email;          this.address = address;      }         @Override      public String toString() {          return "Person [name=" + name + ", age=" + age + ", email=" + email                  + ", address=" + address + "]";      }     }  

适配器类：ListAdapter.java

package com.linc.listview;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.TextView;public class ListAdapter extends ArrayAdapter<Zhang> {private LayoutInflater mInflater; public ListAdapter(Context context, int textViewResourceId,Zhang[] obj) {super(context, textViewResourceId,obj);// TODO Auto-generated constructor stubthis.mInflater = LayoutInflater.from(context);}@Override    public View getView(int position, View convertView, ViewGroup parent) {if(convertView == null){              //创建新的view视图.              convertView = mInflater.inflate(R.layout.listview, null); //see above, you can use the passed resource id.        }                    ViewHolder holder = null;          if(holder==null){              holder = new ViewHolder();              //查找每个ViewItem中,各个子View,放进holder中              holder.name = (TextView) convertView.findViewById(R.id.person_name);              holder.age = (TextView) convertView.findViewById(R.id.person_age);              holder.email = (TextView) convertView.findViewById(R.id.person_email);              holder.address = (TextView) convertView.findViewById(R.id.person_address);              //保存对每个显示的ViewItem中, 各个子View的引用对象              convertView.setTag(holder);          }        else// I think this a bug, program can not run here!!!--linc2014.11.12        {        holder = (ViewHolder)convertView.getTag();         }                  //获取当前要显示的数据          Zhang person = getItem(position);            holder.name.setText(person.getName());          holder.age.setText(String.valueOf(person.getAge()));          holder.email.setText(person.getEmail());          holder.address.setText(person.getAddress());          return convertView;    }    private static class ViewHolder{TextView name;          TextView age;          TextView email;          TextView address;}}

更复杂的一个例子：单行与多行并存

还可以参考：View Tag的介绍

或者对比着GridView来学习一下它们的异同，Android自定义GridView之实现一个图片加多个文本框

它们的Adapter一个是继承自ArrayAdapter，另一个是BaseAdapter。

另外，API demo中相关的例子一定要看看。那才是真正的宝藏呢。

下面直接给出List14源码：

/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.example.android.apis.view;import android.app.ListActivity;import android.content.Context;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.TextView;import android.widget.ImageView;import android.graphics.BitmapFactory;import android.graphics.Bitmap;import com.example.android.apis.R;/** * Demonstrates how to write an efficient list adapter. The adapter used in this example binds * to an ImageView and to a TextView for each row in the list. * * To work efficiently the adapter implemented here uses two techniques: * - It reuses the convertView passed to getView() to avoid inflating View when it is not necessary * - It uses the ViewHolder pattern to avoid calling findViewById() when it is not necessary * * The ViewHolder pattern consists in storing a data structure in the tag of the view returned by * getView(). This data structures contains references to the views we want to bind data to, thus * avoiding calls to findViewById() every time getView() is invoked. */public class List14 extends ListActivity {    private static class EfficientAdapter extends BaseAdapter {        private LayoutInflater mInflater;        private Bitmap mIcon1;        private Bitmap mIcon2;        public EfficientAdapter(Context context) {            // Cache the LayoutInflate to avoid asking for a new one each time.            mInflater = LayoutInflater.from(context);            // Icons bound to the rows.            mIcon1 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_1);            mIcon2 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_2);        }        /**         * The number of items in the list is determined by the number of speeches         * in our array.         *         * @see android.widget.ListAdapter#getCount()         */        public int getCount() {            return DATA.length;        }        /**         * Since the data comes from an array, just returning the index is         * sufficent to get at the data. If we were using a more complex data         * structure, we would return whatever object represents one row in the         * list.         *         * @see android.widget.ListAdapter#getItem(int)         */        public Object getItem(int position) {            return position;        }        /**         * Use the array index as a unique id.         *         * @see android.widget.ListAdapter#getItemId(int)         */        public long getItemId(int position) {            return position;        }        /**         * Make a view to hold each row.         *         * @see android.widget.ListAdapter#getView(int, android.view.View,         *      android.view.ViewGroup)         */        public View getView(int position, View convertView, ViewGroup parent) {            // A ViewHolder keeps references to children views to avoid unneccessary calls            // to findViewById() on each row.            ViewHolder holder;            // When convertView is not null, we can reuse it directly, there is no need            // to reinflate it. We only inflate a new View when the convertView supplied            // by ListView is null.            if (convertView == null) {                convertView = mInflater.inflate(R.layout.list_item_icon_text, null);                // Creates a ViewHolder and store references to the two children views                // we want to bind data to.                holder = new ViewHolder();                holder.text = (TextView) convertView.findViewById(R.id.text);                holder.icon = (ImageView) convertView.findViewById(R.id.icon);                convertView.setTag(holder);            } else {                // Get the ViewHolder back to get fast access to the TextView                // and the ImageView.                holder = (ViewHolder) convertView.getTag();            }            // Bind the data efficiently with the holder.            holder.text.setText(DATA[position]);            holder.icon.setImageBitmap((position & 1) == 1 ? mIcon1 : mIcon2);            return convertView;        }        static class ViewHolder {            TextView text;            ImageView icon;        }    }    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setListAdapter(new EfficientAdapter(this));    }    private static final String[] DATA = Cheeses.sCheeseStrings;}