ANDROID - ExpandableListView [英] ANDROID - ExpandableListView
问题描述
我想弄清楚如何构建一个包含(许多)的视图:
Im trying to figure out how to build a view that contains (many of):
- PARENT1(可检查、可扩展)
- CHILD1(收音机按钮)
- CHILD2(收音机按钮)
...
- PARENT2(可检查、可扩展)
- CHILD1(可检查)
- CHILD2(可检查)
...
重点是父级必须是可检查的，并且基于子级必须更改图标.有人能指出我正确的方向吗，因为从我发现的内容来看似乎对我不起作用.
The point is that parent has to be checkable and based on that children have to change the icon. Can some1 point me into the right direction, because from what i found nothing seems to work for me.
推荐答案
我假设您的数据以某种方式结构化，例如:ArrayList 其中
I assume, you have your data structured somehow, like: ArrayList where
- 父{名称:字符串，检查:布尔值，children:ArrayList} 和
- 子{name:String}
如果是这样，你只需要做两件事:
If so, you only have to do two things:
- 为您创建合适的布局父项渲染器和子项渲染器
- 将 BaseExpandableListAdapter 扩展为自己建立清单.
这里有一个关于我的想法的小样本:
layout/grouprow.xml:
Here is a small sample about what's in my mind:
layout/grouprow.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:orientation="horizontal"
android:gravity="fill" android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<!-- PARENT -->
<TextView android:id="@+id/parentname" android:paddingLeft="5px"
android:paddingRight="5px" android:paddingTop="3px"
android:paddingBottom="3px" android:textStyle="bold" android:textSize="18px"
android:layout_gravity="fill_horizontal" android:gravity="left"
android:layout_height="wrap_content" android:layout_width="wrap_content" />
<CheckBox android:id="@+id/checkbox" android:focusable="false"
android:layout_alignParentRight="true" android:freezesText="false"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_marginTop="5px" />
</RelativeLayout>
layout/childrow.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:padding="0px">
<!-- CHILD -->
<TextView android:id="@+id/childname" android:paddingLeft="15px"
android:paddingRight="5px" android:focusable="false" android:textSize="14px"
android:layout_marginLeft="10px" android:layout_marginRight="3px"
android:layout_width="fill_parent" android:layout_height="wrap_content" />
</LinearLayout>
MyELAdapter 类:我已将其声明为 MyExpandableList 的内部类，因此我可以直接访问父列表，而无需将其作为参数传递.
MyELAdapter class: I've declared this as an inner class of MyExpandableList, so i could reach the list of parents directly, without having to pass it as parameter.
private class MyELAdapter extends BaseExpandableListAdapter
{
private LayoutInflater inflater;
public MyELAdapter()
{
inflater = LayoutInflater.from(MyExpandableList.this);
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parentView)
{
final Parent parent = parents.get(groupPosition);
convertView = inflater.inflate(R.layout.grouprow, parentView, false);
((TextView) convertView.findViewById(R.id.parentname)).setText(parent.getName());
CheckBox checkbox = (CheckBox) convertView.findViewById(R.id.checkbox);
checkbox.setChecked(parent.isChecked());
checkbox.setOnCheckedChangeListener(new CheckUpdateListener(parent));
if (parent.isChecked())
convertView.setBackgroundResource(R.color.red);
else
convertView.setBackgroundResource(R.color.blue);
return convertView;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
View convertView, ViewGroup parentView)
{
final Parent parent = parents.get(groupPosition);
final Child child = parent.getChildren().get(childPosition);
convertView = inflater.inflate(R.layout.childrow, parentView, false);
((TextView) convertView.findViewById(R.id.childname)).setText(child.getName());
return convertView;
}
@Override
public Object getChild(int groupPosition, int childPosition)
{
return parents.get(groupPosition).getChildren().get(childPosition);
}
@Override
public long getChildId(int groupPosition, int childPosition)
{
return childPosition;
}
@Override
public int getChildrenCount(int groupPosition)
{
return parents.get(groupPosition).getChildren().size();
}
@Override
public Object getGroup(int groupPosition)
{
return parents.get(groupPosition);
}
@Override
public int getGroupCount()
{
return parents.size();
}
@Override
public long getGroupId(int groupPosition)
{
return groupPosition;
}
@Override
public void notifyDataSetChanged()
{
super.notifyDataSetChanged();
}
@Override
public boolean isEmpty()
{
return ((parents == null) || parents.isEmpty());
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition)
{
return true;
}
@Override
public boolean hasStableIds()
{
return true;
}
@Override
public boolean areAllItemsEnabled()
{
return true;
}
}
您必须已经有一个公共类 MyExpandableList extends ExpandableListActivity，它有一个成员:
You must already have a public class MyExpandableList extends ExpandableListActivity which has a member:
private ArrayList<Parent> parents;
在为此成员分配值/加载父项列表后，还应将适配器附加到此视图:
after you assign a value to this member / load the list of parents, you should also attach your adapter to this view:
this.setListAdapter(new MyELAdapter());
就是这样.您有一个可检查可扩展列表，并且在 CheckUpdateListener 的 onCheckedChanged(CompoundButton buttonView, boolean isChecked) 方法中，您可以更新父对象的选中状态.
and that's it. You have a checkable-expandable list, and in the CheckUpdateListener's onCheckedChanged(CompoundButton buttonView, boolean isChecked) method you can update your parent object's checked state.
请注意，背景颜色是在 getGroupView 方法中确定的，因此您无需在任何地方更改它，只需在需要时调用适配器的 notifyDataSetChanged() 方法即可.
Note, that the background color is determined in the getGroupView method, so you don't have to change it anywhere, just call the adapter's notifyDataSetChanged() method if needed.
更新
您可以从此链接下载示例源代码.它是一个eclipse项目，但如果你使用的是其他开发环境，只需简单地复制必要的源文件(java + xml).
you can download the sample source code from this link. It is an eclipse project, but if you are using other developer environment, just simply copy the necessary source files (java + xml).
这篇关于ANDROID - ExpandableListView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
