Android入门/ExpandableList(十六)
ExpanableList 折叠列表
主要示例如何实现一个ExpanableList
涵括的知识点:
1.MyExpandableListAdapter适配器 方法说明
2. onChildClick 与 onGroupExpand
3. 使用上下文菜单
下面见Java代码,这里没有用到布局文件,所以没有使用setContentView()
public class mExpandable extends ExpandableListActivity {
private ExpandableListAdapter mAdapter;
private final static String TAG = "mExpandable ====>";
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_m_expandable);
//设置标题
setTitle("可扩展的列表");
// 实例化Adapter
mAdapter = new MyExpandableListAdapter();
//为列表设置adapter
setListAdapter(mAdapter);
//为list注册context菜单
registerForContextMenu(this.getExpandableListView());
}
// ChildClick
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id){
Toast.makeText(this, " 组元素索引: " + groupPosition + " 子元素索引: " + childPosition, Toast.LENGTH_SHORT).show();
return super.onChildClick(parent, v, groupPosition, childPosition, id);
}
// GroupClick
public void onGroupExpand(int groupPosition) {
Toast.makeText(this, " 组元素索引: " + groupPosition, Toast.LENGTH_SHORT).show();
super.onGroupExpand(groupPosition);
}
// 上下文菜单
public void onCreateContextMenu(ContextMenu menu, View v,ContextMenuInfo menuInfo) {
menu.setHeaderTitle("上下文菜单");
menu.add(0, 0, 0, "通过按下轨迹球");
menu.add(0, 1, 0, "D-pad的中键");
menu.add(0, 2, 0, "长按View3秒");
}
public class MyExpandableListAdapter extends BaseExpandableListAdapter {
// 父列表数据
private String[] groups =
{
"浙江省",
"江苏省",
"黑龙江省",
"山东省"
};
// 子列表数据
private String[][] children =
{
{ "杭州","湖州","金华","温州" },
{ "南京", "泰州","苏州","常州","南通", },
{ "哈尔滨市", "齐齐哈尔市", "牡丹江市" },
{ "济南市", "青岛市", "淄博市", "潍坊市" }
};
/**
1.点击 Group时, 会依次调用getChild()方法显示
@return children里对应的数据,比如这里的 [市名]
*/
public Object getChild(int groupPosition, int childPosition) {
Log.v(TAG, "getChild : "+children[groupPosition][childPosition]);
return children[groupPosition][childPosition];
}
/**
1.点击 具体的某个Child时 回调该方法
@return 该Child在Group内的位置 ,比如 Group内第一个,返回为0
*/
public long getChildId(int groupPosition, int childPosition) {
Log.v(TAG, "getChildId : "+childPosition);
return childPosition;
}
/**
1.点击某个Group时, 回调该方法
@return Group下的Child数量
* */
public int getChildrenCount(int groupPosition) {
Log.v(TAG, "getChildrenCount : "+children[groupPosition].length);
return children[groupPosition].length;
}
// 取子列表中的某一项的 View
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent)
{
TextView textView = getGenericView();
textView.setText(getChild(groupPosition, childPosition).toString());
return textView;
}
/**
1.点击Group时 ,回调该方法
@return Group的数据 比如这里的[省名]
* */
@Override
public Object getGroup(int groupPosition) {
Log.v(TAG, "getGroup : "+groups[groupPosition]);
return groups[groupPosition];
}
/**
1.点击Group时 回调该方法
2.点击Child时也会 回调该方法
@return Group的数量
*/
public int getGroupCount() {
Log.v(TAG, "getGroupCount : "+groups.length);
return groups.length;
}
/**
1.点击Group时 回调该方法
2.点击Child时也会 回调该方法
@return 当前点击Group的位置
*/
public long getGroupId(int groupPosition) {
Log.v(TAG, "getGroupId : "+groupPosition);
return groupPosition;
}
// 取父列表中的某一项的 View
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
TextView textView = getGenericView();
textView.setText(getGroup(groupPosition).toString());
return textView;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
// 获取某一项的 View 的逻辑
private TextView getGenericView() {
AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, 48);
TextView textView = new TextView(mExpandable.this);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
textView.setPadding(60, 0, 0, 0);
return textView;
}
}
}
时间匆忙,最近一直没有时间学习android , 感觉拖沓了很多 ..算了,先熟悉下方法使用,然后再深入了解架构吧....