Android使用ExpandableListView实现折叠的效果

ExpandableListView 主要为了显示我们常见的折叠的效果，如下所示：

主要用过一个ExpandableListView+自定义一个继承BaseExpandableListAdapter的适配器实现

不多说直接实现代码：

第一步：首先建议个mian.xml文件文件当中防止一个ExpandableListView控件，

 <ExpandableListView 
        android:id="@+id/android:list"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        ></ExpandableListView>

第二步：写一个适配器:

public class ExpandAdapter extends BaseExpandableListAdapter {

private List<String> group;
private List<List<String>> child;
private Context context;

public ExpandAdapter(){}
public ExpandAdapter(List<String> group,List<List<String>>child,Context context){

this.group = group;
this.child = child;
this.context = context;
}
@Override
public Object getChild(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return this.child.get(groupPosition).get(childPosition);
}

@Override
public long getChildId(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return childPosition;
}

@Override
public View getChildView(int groupPositon, int childPosition, boolean isLastChild, View convertView,
ViewGroup parent) {
// TODO Auto-generated method stub
TextView childView = getTextView();
childView.setText(this.child.get(groupPositon).get(childPosition));
childView.setTextSize(10);
childView.setTextColor(Color.RED);
return childView;
}

private TextView getTextView(){
AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,64);
TextView textView = new TextView(this.context);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
textView.setPadding(36, 0, 0, 0);

return textView;
}

@Override
public int getChildrenCount(int groupPosition) {
// TODO Auto-generated method stub
return this.child.get(groupPosition).size();
}

@Override
public Object getGroup(int groupPosition) {
// TODO Auto-generated method stub
return this.group.get(groupPosition);
}

@Override
public int getGroupCount() {
// TODO Auto-generated method stub
return this.group.size();
}

@Override
public long getGroupId(int groupPosition) {
// TODO Auto-generated method stub
return groupPosition;
}

@Override
public View getGroupView(int groupPosition, boolean isExpand, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
TextView groupView = getTextView();
groupView.setText(this.group.get(groupPosition));
groupView.setTextSize(25);
groupView.setTextColor(Color.YELLOW);
return groupView;
}

@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return false;
}

@Override
public boolean isChildSelectable(int arg0, int arg1) {
// TODO Auto-generated method stub
return true;
}

}
第三步:Activity类讲适配器与listView组合

public class MainActivity extends ExpandableListActivity {

private List<String> group;
private List<List<String>> child;
private ExpandableListView listView ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//设置窗口无标题
requestWindowFeature(Window.FEATURE_NO_TITLE); 
setContentView(R.layout.activity_main);
//
getExpandableListView().setBackgroundResource(R.drawable.ic_launcher);
initView();
getExpandableListView().setAdapter(new ExpandAdapter(this.group,this.child,this));
//设置拖动列表的时候防止出现黑色背景  
getExpandableListView().setCacheColorHint(0);

}


private void initView(){
listView = (ExpandableListView) findViewById(android.R.id.list);
this.group = new ArrayList<String>();
this.child = new ArrayList<List<String>>();

addInfo("网球", new String[]{"费德勒","德约科维奇","纳达尔"});
addInfo("足球运动员", new String[]{"小罗","梅西","马拉多拉"});
addInfo("篮球运动员", new String[]{"乔丹","科比","勒布朗"});


}

private void addInfo(String g,String[] childitem){
this.group.add(g);
List<String> list = new ArrayList<String>();
for (String str : childitem) {
list.add(str);
}
this.child.add(list);
}


}
最终运行效果如上所示。