第七十七讲：用户界面View之ExpandableListView

生活是一面镜子。你对它笑，它就对你笑；你对它哭，它也对你哭。

本讲内容：ExpandableListView 多级列表

下面我们通过一个例子感受一下

下面是res/layout/activity_main.xml 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"
    android:background="@drawable/default_bg"
    tools:context="com.example.expandablelistview.MainActivity$PlaceholderFragment" >

    <ExpandableListView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true">
    </ExpandableListView>

</RelativeLayout>

下面是res/layout/member_listview.xml 布局文件：

<?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="40dp"
    android:layout_gravity="center_horizontal" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:orientation="horizontal" >

        <ImageView
            android:id="@+id/ImageView01"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:paddingTop="10dp"
            android:src="@drawable/user_group" />

        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/tv01"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:textSize="25sp"
                android:textColor="#fff"
                android:gravity="center_vertical"
                android:layout_gravity="center_vertical"
                android:paddingLeft="10dp"/>

            <ImageView
                android:id="@+id/tubiao"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentRight="true"/>

        </RelativeLayout>

    </LinearLayout>

</LinearLayout>

下面是res/layout/member_childitem.xml 布局文件：

<?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:id="@+id/childlayout"
    android:orientation="horizontal" >

    <ImageView
        android:id="@+id/child_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/child_image"
        android:paddingTop="7dp"
        android:layout_marginLeft="40dp"/>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:id="@+id/child_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="17sp"
            android:layout_gravity="center_vertical"
            android:gravity="center_vertical"/>
        <TextView
            android:id="@+id/child_text2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="12sp"
            android:layout_gravity="center_vertical"
            android:gravity="center_vertical"/>

    </LinearLayout>

</LinearLayout>

下面是MainActivity.java主界面文件：

public class MainActivity extends Activity {
	private static final String G_TEXT = "g_text";
	private static final String C_TEXT1 = "c_text1";
	private static final String C_TEXT2 = "c_text2";

	List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
	List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();

	ExAdapter adapter;
	ExpandableListView exList;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		setTitle("溪坎中學");

		for (int i = 0; i < 3; i++) {
			Map<String, String> groupMap = new HashMap<String, String>();
			groupData.add(groupMap);
			// groupMap.put(G_TEXT, "Group"+i);
			if (i == 0) {
				groupMap.put(G_TEXT, "一八班");
			} else if (i == 1) {
				groupMap.put(G_TEXT, "二四班");
			} else if (i == 2) {
				groupMap.put(G_TEXT, "三三班");
			}

			List<Map<String, String>> children = new ArrayList<Map<String, String>>();
			for (int j = 0; j < 5; j++) {
				Map<String, String> childMap = new HashMap<String, String>();
				children.add(childMap);
				if (j == 0) {
					childMap.put(C_TEXT1, "丹妹");
					childMap.put(C_TEXT2, "舍与得，留下的，珍惜。");
				} else if (j == 1) {
					childMap.put(C_TEXT1, "四眼妹");
					childMap.put(C_TEXT2, "太平洋保险，人寿保险，财产保险");
				} else if (j == 2) {
					childMap.put(C_TEXT1, "冯开妥");
					childMap.put(C_TEXT2, "哪一刻，心~停止跳动。");
				} else if (j == 3) {
					childMap.put(C_TEXT1, "郑健美 ");
					childMap.put(C_TEXT2, "爱情就是赌局，谁先爱上谁，谁就输了，我只愿意输一次");
				} else if (j == 4) {
					childMap.put(C_TEXT1, "黄小君");
					childMap.put(C_TEXT2, "挤不进的世界，就别挤了，何苦为难别人，苦了自己。");
				}
			}
			childData.add(children);
		}

		adapter = new ExAdapter(MainActivity.this);
		exList = (ExpandableListView) findViewById(R.id.list);
		exList.setAdapter(adapter);
		exList.setGroupIndicator(null);
		exList.setDivider(null);
	}

	class ExAdapter extends BaseExpandableListAdapter {
		Context context;

		public ExAdapter(Context context) {
			context = this.context;
		}

		public View getGroupView(int groupPosition, boolean isExpanded,
				View convertView, ViewGroup parent) {
			View view = convertView;
			if (view == null) {
				LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
				view = inflater.inflate(R.layout.member_listview, null);
			}

			TextView title = (TextView) view.findViewById(R.id.tv01);// 记得加view否则报错
			title.setText(getGroup(groupPosition).toString());

			ImageView image = (ImageView) view.findViewById(R.id.tubiao);
			if (isExpanded) {
				image.setBackgroundResource(R.drawable.btn_browser2);
			} else {
				image.setBackgroundResource(R.drawable.btn_browser);
			}
			return view;
		}

		public long getGroupId(int groupPosition) {
			return groupPosition;
		}

		public Object getGroup(int groupPosition) {
			return groupData.get(groupPosition).get(G_TEXT).toString();
		}

		public int getGroupCount() {
			return groupData.size();

		}

		public View getChildView(int groupPosition, int childPosition,
				boolean isLastChild, View convertView, ViewGroup parent) {
			View view = convertView;
			if (view == null) {
				LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
				view = inflater.inflate(R.layout.member_childitem, null);
			}
			final TextView title = (TextView) view.findViewById(R.id.child_text);
			title.setText(childData.get(groupPosition).get(childPosition).get(C_TEXT1).toString());
			final TextView title2 = (TextView) view.findViewById(R.id.child_text2);
			title2.setText(childData.get(groupPosition).get(childPosition).get(C_TEXT2).toString());

			return view;
		}

		public long getChildId(int groupPosition, int childPosition) {
			return childPosition;
		}

		public Object getChild(int groupPosition, int childPosition) {
			return childData.get(groupPosition).get(childPosition).get(C_TEXT1).toString();
		}

		public int getChildrenCount(int groupPosition) {
			return childData.get(groupPosition).size();
		}

		// **************************************
		public boolean hasStableIds() {
			return true;
		}

		public boolean isChildSelectable(int groupPosition, int childPosition) {
			return true;
		}

	}
}

本讲就到这里，Take your time and enjoy it