LisView列表视图是Android开发中非常常用的一种视图组件,它是以垂直列表的方式列出需要显示的列表项。
创建ListView可以用ListView组件,也可以继承ListActivity。在使用过程中最重要的是如何设置ListView显示的内容,也就是怎样设置Adapter。Adapter类型可以分为三种:ArrayAdapter,SimpleCursorAdapter和SimpleAdapter。下面介绍这三种Adapter是如何添加列表视图内容的:
一.ArrayAdapter
ArrayAdapter是这三种Adapter最简单的,只能展示一行文字,使用它来添加ListView显示的内容的步骤如下:
1.创建ArrayAdapter
2.调用ListActivity的setListAdapter( )方法来设置显示的内容
下面是具体的例子:
MainActivity.java
- package com.android.listview1.avtivity;
-
-
import android.app.ListActivity;
-
import android.os.Bundle;
-
import android.widget.ArrayAdapter;
-
-
public class MainActivity extends ListActivity {
-
@Override
-
public void onCreate(Bundle savedInstanceState) {
-
super.onCreate(savedInstanceState);
-
-
String[] strs = {"Android","IOS","Mango","MeeGo","Symbian"};
-
-
-
-
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
- android.R.layout.simple_list_item_1,
- strs);
-
- setListAdapter(adapter);
- }
- }
效果图:
二.SimpleCursorAdapter
SimpleCursorAdapter从游标得到的数据进行列表显示,并可以把指定的列映射到对应的TextView中。下面是使用它来显示Android中的联系人姓名的步骤:
1.调用getContentResolver( )方法返回ContentResolver( )对象,通过该对象查询得到Cursor对象
2.创建SimpleCursorAdapter对象
3.调用ListActivity的setListAdapter( )方法显示列表项
下面是具体的例子:
MainActivity.java
- package com.android.listview2.activity;
-
-
import android.app.ListActivity;
-
import android.database.Cursor;
-
import android.os.Bundle;
-
import android.provider.Contacts.People;
-
import android.widget.ListAdapter;
-
import android.widget.SimpleCursorAdapter;
-
-
public class MainActivity extends ListActivity {
-
@Override
-
public void onCreate(Bundle savedInstanceState) {
-
super.onCreate(savedInstanceState);
-
-
Cursor cur = getContentResolver().query(People.CONTENT_URI, null, null, null, null);
-
- startManagingCursor(cur);
-
-
ListAdapter adapter = new SimpleCursorAdapter(this,
- android.R.layout.simple_list_item_1,
- cur,
-
new String[] {People.NAME} ,
-
new int[] {android.R.id.text1});
-
- setListAdapter(adapter);
- }
- }
在AndroidManifest.xml文件中添加17行的声明
- <?xml version="1.0" encoding="utf-8"?>
-
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-
package="com.android.listview2.activity"
-
android:versionCode="1"
-
android:versionName="1.0">
-
<uses-sdk android:minSdkVersion="10" />
-
-
<application android:icon="@drawable/icon" android:label="@string/app_name">
-
<activity android:name=".MainActivity"
-
android:label="@string/app_name">
-
<intent-filter>
-
<action android:name="android.intent.action.MAIN" />
-
<category android:name="android.intent.category.LAUNCHER" />
-
</intent-filter>
-
</activity>
-
</application>
-
<uses-permission android:name="android.permission.READ_CONTACTS"></uses-permission>
-
</manifest>
效果图:
三.SimpleAdapter
SimpleAdapter可以定义各种不同的布局,可以添加ImageView(图片),Button(按钮),CheckBox(复选框)等。
下面是添加图片的例子:
MainActivity.java
- package com.android.listview3.activity;
-
-
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.widget.SimpleAdapter;
-
-
public class MainActivity extends ListActivity {
-
-
@Override
-
public void onCreate(Bundle savedInstanceState) {
-
-
super.onCreate(savedInstanceState);
-
-
SimpleAdapter adapter = new SimpleAdapter(this, getData(),
-
R.layout.main,
-
new String[] { "title", "img" },
-
new int[] { R.id.title, R.id.img });
-
-
- setListAdapter(adapter);
- }
-
-
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("title", "摩托罗拉");
-
map.put("img", R.drawable.pic1);
- list.add(map);
-
-
map = new HashMap<String, Object>();
-
map.put("title", "诺基亚");
-
map.put("img", R.drawable.pic2);
- list.add(map);
-
-
map = new HashMap<String, Object>();
-
map.put("title", "三星");
-
map.put("img", R.drawable.pic3);
- list.add(map);
-
-
return list;
- }
- }
main.xml
- <?xml version="1.0" encoding="utf-8"?>
-
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-
android:orientation="horizontal"
-
android:layout_width="fill_parent"
-
android:layout_height="fill_parent"
-
>
-
<ImageView
-
android:id="@+id/img"
-
android:layout_width="wrap_content"
-
android:layout_height="wrap_content"
-
android:layout_margin="5px"
-
/>
-
<TextView
-
android:id="@+id/title"
-
android:layout_width="wrap_content"
-
android:layout_height="wrap_content"
-
android:textColor="#ffffff"
-
android:textSize="20px"
-
/>
-
</LinearLayout>
效果图:
注:上面的程序很多地方用到泛型编程,有关Java泛型编程的资料请看:
http://liangruijun.blog.51cto.com/3061169/636850
http://www.cnblogs.com/panjun-Donet/archive/2008/09/27/1300609.html
本文转自 lingdududu 51CTO博客,原文链接:
http://blog.51cto.com/liangruijun/646049