Android ListView实现方法二

Screen Layout

ListActivity has a default layout that consists of a single, full-screen list in the center of the screen. However, if you desire, you can customize the screen layout by setting your own view layout with setContentView() in onCreate(). To do this, your own view MUST contain a ListView object with the id "@android:id/list" (or list if it's in code)

Optionally, your custom view can contain another view object of any type to display when the list view is empty. This "empty list" notifier must have an id "android:id/empty". Note that when an empty view is present, the list view will be hidden when there is no data to display.

The following code demonstrates an (ugly) custom screen layout. It has a list with a green background, and an alternate red "no data" message.

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"         android:orientation="vertical"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:paddingLeft="8dp"         android:paddingRight="8dp">     <ListView android:id="@android:id/list"               android:layout_width="match_parent"               android:layout_height="match_parent"               android:background="#00FF00"               android:layout_weight="1"               android:drawSelectorOnTop="false"/>     <TextView android:id="@android:id/empty"               android:layout_width="match_parent"               android:layout_height="match_parent"               android:background="#FF0000"               android:text="No data"/> </LinearLayout>

Row Layout

You can specify the layout of individual rows in the list. You do this by specifying a layout resource in the ListAdapter object hosted by the activity (the ListAdapter binds the ListView to the data; more on this later).

A ListAdapter constructor takes a parameter that specifies a layout resource for each row. It also has two additional parameters that let you specify which data field to associate with which object in the row layout resource. These two parameters are typically parallel arrays.

Android provides some standard row layout resources. These are in the R.layout class, and have names such as simple_list_item_1, simple_list_item_2, and two_line_list_item. The following layout XML is the source for the resource two_line_list_item, which displays two data fields,one above the other, for each list row.

<?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="wrap_content"     android:orientation="vertical">     <TextView android:id="@+id/text1"         android:textSize="16sp"         android:textStyle="bold"         android:layout_width="match_parent"         android:layout_height="wrap_content"/>     <TextView android:id="@+id/text2"         android:textSize="16sp"         android:layout_width="match_parent"         android:layout_height="wrap_content"/> </LinearLayout>

Binding to Data

You bind the ListActivity's ListView object to data using a class that implements the ListAdapter interface. Android provides two standard list adapters: SimpleAdapter for static data (Maps), and SimpleCursorAdapter for Cursor query results.

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,arrayData);//采用布局文件来布局setContentView(R.layout.activity_main);ListView listview = (ListView) this.findViewById(R.id.listView);listview.setAdapter(adapter);listview.setOnItemClickListener(new OnItemClickListener() {public void onItemClick(AdapterView<?> arg0, View arg1, int position,long id) {//列表项单击事件}});