Android中ExpandableListView的用法实例

本文实例讲述了Android中ExpandableListView的用法，ExpandableListView是android中可以实现下拉list的一个控件，具体的实现方法如下：

首先：在layout的xml文件中定义一个ExpandableListView

代码如下:

<LinearLayout  
    android:id="@+id/linearLayout" 
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent" 
    androidrientation="vertical" 
    > 
     
    <ExpandableListView 
    android:id="@+id/expandableListView" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
        /> 
</LinearLayout>

定义两个List，用来存放控件中Group/Child中的String

代码如下:

private List<String> groupArray; 
private List<List<String>> childArray;

对这两个List进行初始化，并插入一些数据

代码如下:

groupArray = new ArrayList<String>(); 
childArray = new ArrayList<List<String>>(); 
 
groupArray.add("第一行"); 
groupArray.add("第二行"); 
 
List<String> tempArray = new ArrayList<String>(); 
tempArray.add("第一条"); 
tempArray.add("第二条"); 
tempArray.add("第三条"); 
 
for(int index = 0; index <groupArray.size(); ++index) 
{ 
    childArray.add(tempArray); 
}

定义ExpandableListView的Adapter

代码如下:

//ExpandableListView的Adapter 
public class ExpandableAdapter extends BaseExpandableListAdapter 
{ 
    Activity activity; 
     
    public ExpandableAdapter(Activity a) 
    { 
        activity = a; 
    } 
    public Object getChild(int groupPosition, int childPosition) 
    { 
        return childArray.get(groupPosition).get(childPosition); 
    } 
    public long getChildId(int groupPosition, int childPosition) 
    { 
        return childPosition; 
    } 
    public int getChildrenCount(int groupPosition) 
    { 
        return childArray.get(groupPosition).size(); 
    } 
    public View getChildView(int groupPosition, int childPosition, 
            boolean isLastChild, View convertView, ViewGroup parent) 
    { 
        String string = childArray.get(groupPosition).get(childPosition); 
        return getGenericView(string); 
    } 
    // group method stub 
    public Object getGroup(int groupPosition) 
    { 
        return groupArray.get(groupPosition); 
    } 
    public int getGroupCount() 
    { 
        return groupArray.size(); 
    } 
    public long getGroupId(int groupPosition) 
    { 
        return groupPosition; 
    } 
    public View getGroupView(int groupPosition, boolean isExpanded, 
            View convertView, ViewGroup parent) 
    { 
        String string = groupArray.get(groupPosition); 
        return getGenericView(string); 
    } 
    // View stub to create Group/Children 's View 
    public TextView getGenericView(String string) 
    { 
        // Layout parameters for the ExpandableListView 
        AbsListView.LayoutParams layoutParams = new AbsListView.LayoutParams( 
                ViewGroup.LayoutParams.FILL_PARENT, 64); 
        TextView text = new TextView(activity); 
        text.setLayoutParams(layoutParams); 
        // Center the text vertically 
        text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT); 
        // Set the text starting position 
        text.setPadding(36, 0, 0, 0); 
        text.setText(string); 
        return text; 
    } 
    public boolean hasStableIds() 
    { 
        return false; 
    } 
    public boolean isChildSelectable(int groupPosition, int childPosition) 
    { 
        return true; 
    } 
}

最后，给定义好的ExpandableListView添加上Adapter

代码如下:

ExpandableListView expandableListView = (ExpandableListView)findViewById(R.id.expandableListView); 
expandableListView.setAdapter(new ExpandableAdapter(Main.this));

希望本文所述对大家的Android程序设计有所帮助。