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

<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

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

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

//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

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。