使用ExpandableListView实现一个时光轴

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。

Demo下载http://download.csdn.net/detail/u012702547/9297507