在许多App上都能看到时光轴的效果，比如携程等等，那么我们今天就利用ExpandableListView来实现一个时光轴效果，先来看看效果图：
效果还是挺简单的，这里我们主要是采用ExpandableListView来实现，关于ExpandableListView的详细使用参见(android开发之ExpandableListView的使用，实现类似QQ好友列表)，我们这里主要介绍这个效果的实现：
先来看看主布局文件：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" > <TextView
android:id="@+id/title_p"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_margin="12dp"
android:gravity="center"
android:text="2015年11月"
android:textSize="18sp" /> <View
android:id="@+id/hor_div"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_below="@id/title_p"
android:background="#9F79EE" /> <View
android:id="@+id/ver_div"
android:layout_width="1dp"
android:layout_height="match_parent"
android:layout_below="@id/hor_div"
android:layout_marginLeft="70dp"
android:background="#9F79EE" /> <TextView
android:id="@+id/title_c"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/hor_div"
android:layout_marginLeft="60dp"
android:paddingBottom="12dp"
android:paddingLeft="18dp"
android:paddingTop="12dp"
android:text="时光轴"
android:textSize="24sp" /> <ExpandableListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/title_c"
android:layout_marginLeft="60dp"
android:background="@null"
android:clickable="false"
android:divider="@null" >
</ExpandableListView></RelativeLayout>
两条分割线用View来做，整体不难，不多说，看看MainActivity
public class MainActivity extends Activity {private List<TimeLineBean> list;
private ExpandableListView lv;@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
initData();
initView();
}private void initView() {
lv = (ExpandableListView) this.findViewById(R.id.lv);
lv.setAdapter(new MyAdapter(MainActivity.this, list));
for (int i = 0; i < list.size(); i++) {
lv.expandGroup(i);
}
lv.setGroupIndicator(null);
lv.setOnGroupClickListener(new OnGroupClickListener() {@Override
public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {
return true;
}
});
}private void initData() {
list = new ArrayList<TimeLineBean>();
List<String> things = new ArrayList<String>();
things.add("六王毕，四海一；");
things.add("蜀山兀，阿房出。");
things.add("覆压三百余里，隔离天日。");
list.add(new TimeLineBean("11月24日", things));
things = new ArrayList<String>();
things.add("骊山北构而西折，");
things.add("直走咸阳。");
things.add("二川溶溶，流入宫墙。");
list.add(new TimeLineBean("11月23日", things));
things = new ArrayList<String>();
things.add("五步一楼，十步一阁；");
things.add("廊腰缦回，");
list.add(new TimeLineBean("11月22日", things));
things = new ArrayList<String>();
things.add("檐牙高啄；");
things.add("各抱地势，钩心斗角。");
things.add("盘盘焉，囷囷焉，蜂房水涡，");
things.add("矗不知乎几千万落！");
list.add(new TimeLineBean("11月21日", things));
things = new ArrayList<String>();
things.add("长桥卧波，未云何龙？");
things.add("複道行空，不霁何虹？");
things.add("高低冥迷，不知西东。");
list.add(new TimeLineBean("11月20日", things));
things = new ArrayList<String>();
things.add("歌台暖响，");
things.add("春光融融；");
list.add(new TimeLineBean("11月19日", things));
things = new ArrayList<String>();
things.add("舞殿冷袖，");
things.add("风雨凄凄。");
things.add("一日之内，一宫之间，");
things.add("而气候不齐。");
list.add(new TimeLineBean("11月18日", things));
}
}
在MainActivity中我们先初始化模拟数据，然后初始化View，初始化View的过程中，通过一个for循环让所有的group展开，然后再屏蔽掉group的点击事件，好了，再来看看Adapter：
public class MyAdapter extends BaseExpandableListAdapter {private Context context;
private List<TimeLineBean> list;public MyAdapter(Context context, List<TimeLineBean> list) {
this.context = context;
this.list = list;
}@Override
public Object getChild(int groupPosition, int childPosition) {
return list.get(groupPosition).getThings();
}@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView,
ViewGroup parent) {
ChildHolder holder = null;
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.child_item, null);
holder = new ChildHolder();
holder.tv = (TextView) convertView.findViewById(R.id.ci_thing);
convertView.setTag(holder);
} else {
holder = (ChildHolder) convertView.getTag();
}
holder.tv.setText(list.get(groupPosition).getThings().get(childPosition));
return convertView;
}@Override
public int getChildrenCount(int groupPosition) {
return list.get(groupPosition).getThings().size();
}@Override
public Object getGroup(int groupPosition) {
return list.get(groupPosition).getDate();
}@Override
public int getGroupCount() {
return list.size();
}@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
GroupHolder holder = null;
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.group_item, null);
holder = new GroupHolder();
holder.tv = (TextView) convertView.findViewById(R.id.gi_date);
convertView.setTag(holder);
} else {
holder = (GroupHolder) convertView.getTag();
}
holder.tv.setText(list.get(groupPosition).getDate());
return convertView;
}@Override
public boolean hasStableIds() {
return false;
}@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
}class GroupHolder {
TextView tv;
}class ChildHolder {
TextView tv;
}}
这个Adapter也没啥讲的，大家如果有疑问可以参见android开发之ExpandableListView的使用，实现类似QQ好友列表，这里有ExpandableListView的详细介绍。最后就是两个item文件：
group_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" > <View
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_marginTop="22dp"
android:background="@drawable/circle" /> <TextView
android:id="@+id/gi_date"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="16dp"
android:paddingLeft="12dp"
android:paddingTop="18dp"
android:text="11月24号"
android:textSize="22sp" /></LinearLayout>
child_item.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" > <TextView
android:id="@+id/ci_thing"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="22dp"
android:paddingTop="8dp"
android:text="11月24号"
android:textColor="#999999"
android:textSize="16sp" /></LinearLayout>
每个group_item的前面有一个红色的实心球，这个球我们用shape来绘制，关于shape的使用参见android开发之shape详解：
circle.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" > <corners android:radius="10dp" /> <size
android:height="10dp"
android:width="10dp" /> <solid android:color="#FF6A6A" /></shape>
好了，这个东西貌似没难度，其实就是ExpandableListView的使用。
