【发布时间】:2009-08-30 04:40:10
【问题描述】:
是否可以在可扩展列表中自定义子项?
【问题讨论】:
标签: android expandablelistview expandablelistadapter
是否可以在可扩展列表中自定义子项?
【问题讨论】:
标签: android expandablelistview expandablelistadapter
使用SimpleExpandableListAdapter 绝非易事。假设您使用的是ExpandableListActivity,下面是一些可以帮助您入门的代码。
在这个例子中,我们使用标准的android.R.layout.simple_expandable_list_item_1 作为我们的组头视图,但我们使用我们自己的自定义布局给孩子们。
// Construct Expandable List
final String NAME = "name";
final String IMAGE = "image";
final LayoutInflater layoutInflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final ArrayList<HashMap<String, String>> headerData = new ArrayList<HashMap<String, String>>();
final HashMap<String, String> group1 = new HashMap<String, String>();
group1.put(NAME, "Group 1");
headerData.add( group1 );
final HashMap<String, String> group2 = new HashMap<String, String>();
group2.put(NAME, "Group 2");
headerData.add( group2);
final ArrayList<ArrayList<HashMap<String, Object>>> childData = new ArrayList<ArrayList<HashMap<String, Object>>>();
final ArrayList<HashMap<String, Object>> group1data = new ArrayList<HashMap<String, Object>>();
childData.add(group1data);
final ArrayList<HashMap<String, Object>> group2data = new ArrayList<HashMap<String, Object>>();
childData.add(group2data);
// Set up some sample data in both groups
for( int i=0; i<10; ++i) {
final HashMap<String, Object> map = new HashMap<String,Object>();
map.put(NAME, "Child " + i );
map.put(IMAGE, getResources().getDrawable(R.drawable.icon));
( i%2==0 ? group1data : group2data ).add(map);
}
setListAdapter( new SimpleExpandableListAdapter(
this,
headerData,
android.R.layout.simple_expandable_list_item_1,
new String[] { NAME }, // the name of the field data
new int[] { android.R.id.text1 }, // the text field to populate with the field data
childData,
0,
null,
new int[] {}
) {
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
final View v = super.getChildView(groupPosition, childPosition, isLastChild, convertView, parent);
// Populate your custom view here
((TextView)v.findViewById(R.id.name)).setText( (String) ((Map<String,Object>)getChild(groupPosition, childPosition)).get(NAME) );
((ImageView)v.findViewById(R.id.image)).setImageDrawable( (Drawable) ((Map<String,Object>)getChild(groupPosition, childPosition)).get(IMAGE) );
return v;
}
@Override
public View newChildView(boolean isLastChild, ViewGroup parent) {
return layoutInflater.inflate(R.layout.expandable_list_item_with_image, null, false);
}
}
);
在您的自定义子布局中,命名为expandable_list_item_with_image.xml:
<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right" />
</RelativeLayout>
【讨论】:
您可以尝试制作自己的列表适配器来扩展 BaseExpandableListAdapter,就像在 documentation 中描述的那样。
然后覆盖getGroupView(..)(父项,或getChildView子项)函数,在这个函数中你可以膨胀你自己的布局xml。
类似这样的:
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent)
{
View v = convertView;
if (v == null) {
//sender is activity from where you call this adapter. Set it with construktor.
LayoutInflater vi = (LayoutInflater)sender.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.row, null);
}
//children = arraylists of Child
Child c = children.get(childPosition);
if (c != null) {
TextView tt = (TextView) v.findViewById(R.id.toptext);
TextView bt = (TextView) v.findViewById(R.id.bottomtext);
ImageView icon = (ImageView) v.findViewById(R.id.rowicon);
if (tt != null) {
tt.setText(c.text1); }
if(bt != null){
bt.setText(c.text2);
}
if (icon != null)
{
icon.setImageResource(R.drawable.rowicon);
}
}
return v;
}
布局xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip">
<ImageView
android:id="@+id/rowicon"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_marginRight="6dip" />
<LinearLayout
android:orientation="vertical"
android:layout_width="0dip"
android:layout_weight="1"
android:layout_height="fill_parent">
<TextView
android:id="@+id/toptext"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:gravity="center_vertical"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:id="@+id/bottomtext"
android:singleLine="true"
android:ellipsize="marquee"
/>
</LinearLayout>
</LinearLayout>
【讨论】:
覆盖getGroupView后,可以使用setCompoundDrawablesWithIntrinsicBounds函数添加图片。
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
{
View v = super.getGroupView(groupPosition, isExpanded, convertView, parent);
TextView tv = (TextView) v.findViewById(R.id.textViewId);
tv.setCompoundDrawablesWithIntrinsicBounds(R.drawable.imageToAdd, 0, 0, 0);
return v;
}
【讨论】:
我刚刚找到了一个更好的方法,你可以简单地添加
android:drawableRight="@drawable/icon" 行布局列表组的 xml 文件。
【讨论】:
试试这个>>> Tutorial
您可以更新它以便在子 xml 文件中添加图像而不是文本
【讨论】: