基本的ListView实现

整个的流程描述下来就是
  主Activity继承ListActivity , 主Activity布局文件中加入id为android:list的Listview控件
  主Activity里准备需要显示的数据 ArrayList ,
   写好对应的每一行的显示布局文件 ,  然后用Adapter来加载这个布局文件, 
  Activity中实例化Adapter的时候传入需要显示的数据ArrayList,  Adapter实例化了后调用setListAdapter, 结束
  处理点击某一行, 重新ListActivity的onListItemClick方法.


1.  继承ListActivity 
2.  准备数据 ArrayList <HashMap<String,String>> list 

3.  创建类MyAdapter继承SimpleAdapter, 构造函数中创建一个LayoutInflater对象, 并重写getView方法加载数据显示的xml文件

4.  实例化adapter对象, 并调用ListActivity的方法setListAdapter(myAdapter);  

5.  修改主Activity的布局文件, 加入id为android:list的Listview控件

6.  需要处理点击事件的话 重写onListItemClick

SimpleAdapter<strong>public abstract classLayoutInflaterextends Object</strong>java.lang.Object   ↳ android.view.LayoutInflaterClass OverviewInstantiates a layout XML file into its corresponding View objects. It is never used directly. Instead, use getLayoutInflater() or getSystemService(Class) to retrieve a standard LayoutInflater instance that is already hooked up to the current context and correctly configured for the device you are running on. For example:LayoutInflater inflater = (LayoutInflater)context.getSystemService      (Context.LAYOUT_INFLATER_SERVICE);To create a new LayoutInflater with an additional LayoutInflater.Factory for your own views, you can use cloneInContext(Context) to clone an existing ViewFactory, and then call setFactory(LayoutInflater.Factory) on it to include your Factory.For performance reasons, view inflation relies heavily on pre-processing of XML files that is done at build time. Therefore, it is not currently possible to use LayoutInflater with an XmlPullParser over a plain XML file at runtime; it only works with an XmlPullParser returned from a compiled resource (R.something file.)Public Methods:static LayoutInflater from(Context context)Obtains the LayoutInflater from the given context. ==============================================<strong>public classSimpleAdapterextends BaseAdapterimplements Filterable ThemedSpinnerAdapter</strong>Class OverviewAn easy adapter to map static data to views defined in an XML file. You can specify the data backing the list as an ArrayList of Maps. Each entry in the ArrayList corresponds to one row in the list. The Maps contain the data for each row. You also specify an XML file that defines the views used to display the row, and a mapping from keys in the Map to specific views. Binding data to views occurs in two phases. First, if a SimpleAdapter.ViewBinder is available, setViewValue(android.view.View, Object, String) is invoked. If the returned value is true, binding has occurred. If the returned value is false, the following views are then tried in order:    A view that implements Checkable (e.g. CheckBox). The expected bind value is a boolean.    TextView. The expected bind value is a string and setViewText(TextView, String) is invoked.    ImageView. The expected bind value is a resource id or a string and setViewImage(ImageView, int) or setViewImage(ImageView, String) is invoked. If no appropriate binding can be found, an IllegalStateException is thrown. <strong>Public ConstructorsSimpleAdapter(Context context, List<? extends Map<String, ?>> data, int resource, String[] from, int[] to)</strong> Public Methods: View getView(int position, View convertView, ViewGroup parent)Get a View that displays the data at the specified position in the data set. setListAdapter(myAdapter);  这个方法属于ListActivity<pre name="code" class="java"><span style="font-family: Arial, Helvetica, sans-serif;">所以我们的显示List的Activity要继承这个类</span>

错误
11-22 03:26:29.635: E/AndroidRuntime(2130): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.simplelistview/com.example.simplelistview.ActivityIndex}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'


在需要显示的Layout里必须有ListView控件, 并且ID叫android:list


    <ListView android:id="@+id/android:list" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:drawSelectorOnTop="true"

android:scrollbars="vertical" />

public class ActivityIndex extends ListActivity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.index);ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();HashMap<String, String> map1 = new HashMap<String, String>();map1.put("user_name", "zhangsan");map1.put("user_ip", "192.168.1.1");HashMap<String, String> map2 = new HashMap<String, String>();map2.put("user_name", "lisi");map2.put("user_ip", "192.168.1.2");HashMap<String, String> map3 = new HashMap<String, String>();map3.put("user_name", "wangwu");map3.put("user_ip", "192.168.1.3");list.add(map1);list.add(map2);list.add(map3);MyAdapter myAdapter = new MyAdapter(ActivityIndex.this, list,R.layout.user, new String[] { "user_name", "user_ip" },new int[] { R.id.user_name, R.id.user_ip });setListAdapter(myAdapter);}@Overrideprotected void onListItemClick(ListView l, View v, int position, long id) {// TODO Auto-generated method stubsuper.onListItemClick(l, v, position, id);System.out.println("id -------------" + id);System.out.println("position----------" + position);}}

Adapter

public class MyAdapter extends SimpleAdapter {private LayoutInflater inflater = null;private List<HashMap<String, String>> style = null;public MyAdapter(Context context, List<? extends Map<String, ?>> data,int resource, String[] from, int[] to) {super(context, data, resource, from, to);// this.inflater = new LayoutInflater.from(context);inflater = LayoutInflater.from(context);}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View result = super.getView(position, convertView, parent);// System.out.println("possition ----->" + position);if (result != null) {inflater.inflate(R.layout.user, null);}return result;}}

user.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/user_name"        android:layout_height="30dip"        android:layout_width="180dip"        android:textSize="12pt"        android:singleLine="true"/>            <TextView         android:id="@+id/user_ip"        android:layout_height="fill_parent"        android:layout_width="fill_parent"        android:textSize="12pt"        android:singleLine="true"/></LinearLayout>