ExpandableListView的使用

最新推荐文章于 2017-09-04 21:01:53 发布

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#string #android #layout #parameters #object #list

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本文介绍如何使用 Android 的 ExpandableListView 控件来创建可展开的列表视图。通过定义布局、初始化数据结构并设置适配器，可以轻松实现带有组和子项的列表。

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

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; } }

最后个定义好的ExpandableListView添加Adapter

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