ListView是很常见的一个UI组件，在许多App中都很常用，其意思就是可滚动的列表，使用ListView必须使用Adapter（适配器），常用的适配器友谊ArrayAdapter,SimpleAdapter,BaseAdapter.
ListView一些特殊的属性是：
android:divider="@drawable/red"//每个列表项之间的分割线
android:entries="@drawable/books"//列表项显示的数据
布局代码示例：
<ListView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="@drawable/red"
android:entries="@drawable/books">
</LIstView>
第一我们使用SimpleAdapter来写一个ListView：
public class SimpleAdapter extends Activity{
private String[] names =new String[]{"nick","lebron","kobe","kevin"};
private int[] imgsIds[] =new Int[] {R.drawable.1,R.drawable.2,R.drawable.3,R.drawable.4};
@Override
public void onCreate(Bundle savedInsatnceState)
{
super.onCreate(savedInsatnceState);
setTitle("simpleadapter");
setContentView(R.layout.main);
List<Map><String,Object> list=new ArrayList<Map><String,Object>（）;//创建动态数组ArrayList
for(int i=0;i<names.length;i++){
Map<String,Object> map=new HashMap=<String,Object>;
map.put("name",names[i]);
map.put("headerImg",imgsIds[i]);
list.add(map);
}
SimpleAdapter adapter=new SimpleAdaper(this,list,R.layout.main,new String[]{"name","headerImg"},new int[]{R.id.name,R.id.headerImg});
ListView list=(ListView)findViewById(R.id.mylist);
list.setAdaper(adapter);
}
}
*注释*
SimpleAdapter是另一种常见的adapter类型，其有五个参数
1：Activity.this
2：传入的数据
3：数据传入的界面
4：数据中Map类型数据的String 类的key
5：穿入界面的组件的Id
**
第二种我们使用ArrayAdapter：代码不详解，只是重写Adapter：
String[] str={"china","america","japan"};
List list=new ArrayList<String>();
for(int i=0;i<str.length;i++){
list.add(str[i]);
}
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.simple_list_item2,list);
*注释*
第三个属性指定要显示每一个ListItem的风格：
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.simple_list_item1,list);：普通文本框
ArrayAdapter<String> adapter=new ArrayAdapetr<String>(this,R.layout.simple_list_multiple_choice);：多选框
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.simple_list_single_choice);：单选框
**
另外，ListView还有一个拓展组件ExpandableListView，就是可拓展的列表，但是他的适配器必须使用ExpandableAdapter：
public class ExpandableListViewTest extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//创建一个BaseExpandableListAdapter对象
ExpandableListAdapter adapter = new BaseExpandableListAdapter()
{
int[] logos = new int[]
{
R.drawable.p,
R.drawable.z,
R.drawable.t
};
private String[] armTypes = new String[]
{ "神族兵种", "虫族兵种", "人族兵种"};
private String[][] arms = new String[][]
{
{ "狂战士", "龙骑士", "黑暗圣堂", "电兵" },
{ "小狗", "刺蛇", "飞龙", "自爆飞机" },
{ "机枪兵", "护士MM" , "幽灵" }
};
//获取指定组位置、指定子列表项处的子列表项数据
@Override
public Object getChild(int groupPosition, int childPosition)
{
return arms[groupPosition][childPosition];
}
@Override
public long getChildId(int groupPosition, int childPosition)
{
return childPosition;
}
@Override
public int getChildrenCount(int groupPosition)
{
return arms[groupPosition].length;
}
private TextView getTextView()
{
AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, 64);
TextView textView = new TextView(ExpandableListViewTest.this);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
textView.setPadding(36, 0, 0, 0);
textView.setTextSize(20);
return textView;
}
//该方法决定每个子选项的外观
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent)
{
TextView textView = getTextView();
textView.setText(getChild(groupPosition, childPosition).toString());
return textView;
}
//获取指定组位置处的组数据
@Override
public Object getGroup(int groupPosition)
{
return armTypes[groupPosition];
}
@Override
public int getGroupCount()
{
return armTypes.length;
}
@Override
public long getGroupId(int groupPosition)
{
return groupPosition;
}
//该方法决定每个组选项的外观
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent)
{
LinearLayout ll = new LinearLayout(ExpandableListViewTest.this);
ll.setOrientation(0);
ImageView logo = new ImageView(ExpandableListViewTest.this);
logo.setImageResource(logos[groupPosition]);
ll.addView(logo);
TextView textView = getTextView();
textView.setText(getGroup(groupPosition).toString());
ll.addView(textView);
return ll;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition)
{
return true;
}
@Override
public boolean hasStableIds()
{
return true;
}
};
ExpandableListView expandListView = (ExpandableListView)
findViewById(R.id.list);
expandListView.setAdapter(adapter);
}
}
使用ExpandableAdapter，我们重新首先重写其中的一些方法，每一个getGroupView就是显示的每一个ListGroupItem（列表项），其中重写的getGroupCount方法放回的就是有多少列表项，而getChildView（）就是显示每一个子列表项，同理getChildCount（）每一个列表项里面的子列表项个数。