Android学习笔记之：实现树形层级ListView

 我们在做开的的时候，百分之百会用到列表展示控件ListView，但是有的时候我们展示的数据是分多层次的，

比如我们的省市区县列表等，这种 数据是一种从属关系，如果要在一个页面展示的话，
我们应该如何操作呢？之前我第一想想法是用Expandablelistview，但是只能实现两展示，
一下子恍然大悟，原来可以这样做。感谢老师的无私奉献，把学习的知识做个笔记，以后肯定用得上！
直接贴代码，代码中有相应注释：
主界面Activity，布局就只一个ListView:

public class MainActivity extends Activity {private ListView mListView;private TreeListViewAdapter<TestBean> mAdapter;private List<TestBean> mDatas = new ArrayList<TestBean>();@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.activity_main);this.mListView = (ListView) findViewById(R.id.listview);initTestDatas();try {mAdapter = new TreeListViewAdapter<TestBean>(mListView, this, mDatas, 0);}catch (Exception e) {e.printStackTrace();}this.mListView.setAdapter(mAdapter);mAdapter.setmTreeListener(new TreeViewOnItemClick() {@Overridepublic void onTreeItemClick(int position, Node node) {Toast.makeText(MainActivity.this, "你点击的是：" + node.getName(), Toast.LENGTH_SHORT).show();}});this.mListView.setOnItemLongClickListener(new OnItemLongClickListener() {@Overridepublic boolean onItemLongClick(AdapterView<?> arg0, View arg1, final int arg2, long arg3) {final EditText edt = new EditText(MainActivity.this);new AlertDialog.Builder(MainActivity.this).setTitle("Insert").setView(edt).setPositiveButton("submit", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {if (TextUtils.isEmpty(edt.getText().toString())) {Toast.makeText(MainActivity.this, "请填写添加内容", Toast.LENGTH_SHORT).show();}else {mAdapter.insertNodeData(arg2, edt.getText().toString());}}}).setNegativeButton("Cancel", null).create().show();return true;}});}private void initTestDatas() {TestBean bean = null;bean = new TestBean(1, 0, "文件目录1");mDatas.add(bean);bean = new TestBean(2, 0, "文件目录2");mDatas.add(bean);bean = new TestBean(3, 0, "文件目录3");mDatas.add(bean);bean = new TestBean(4, 1, "文件目录4");mDatas.add(bean);bean = new TestBean(5, 1, "文件目录5");mDatas.add(bean);bean = new TestBean(6, 2, "文件目录6");mDatas.add(bean);bean = new TestBean(7, 2, "文件目录7");mDatas.add(bean);bean = new TestBean(8, 3, "文件目录8");mDatas.add(bean);bean = new TestBean(9, 3, "文件目录9");mDatas.add(bean);bean = new TestBean(10, 0, "文件目录10");mDatas.add(bean);}}

数据适配器基类：

** * 树形ListView的数据适配器类 * @description： * @author ldm * @date 2015-10-9 上午9:47:01 */public abstract class TreeViewBaseAdapter<T> extends BaseAdapter {protected Context context;protected List<T> datas;protected List<Node> mAllNodes;protected List<Node> mVisibleNodes;protected LayoutInflater mInflater;protected ListView treeLv;protected TreeViewOnItemClick mTreeListener;public TreeViewBaseAdapter(ListView treeLv, Context context, List<T> datas, int defaultExpandLevel) throws IllegalAccessException, IllegalArgumentException {this.context = context;this.treeLv = treeLv;mInflater = LayoutInflater.from(context);mAllNodes = TreeHelperTools.getSortedNodes(datas, defaultExpandLevel);mVisibleNodes = TreeHelperTools.filterVisibleNodes(mAllNodes);this.treeLv.setOnItemClickListener(new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {expandOrCollapse(position);if(mTreeListener!=null){mTreeListener.onTreeItemClick(position, mVisibleNodes.get(position));}}});}public void setmTreeListener(TreeViewOnItemClick mTreeListener) {this.mTreeListener = mTreeListener;}/*** 设置ListView点击item节点时，是否应该展开* @description：* @author ldm* @date 2015-10-10 上午9:05:08*/protected void expandOrCollapse(int position) {Node n=mVisibleNodes.get(position);if(n!=null){if(n.isLeaf()){return;}n.setExpand(!n.isExpand());mVisibleNodes=TreeHelperTools.filterVisibleNodes(mAllNodes);notifyDataSetChanged();}}@Overridepublic int getCount() {// TODO Auto-generated method stubreturn mVisibleNodes.size();}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn mVisibleNodes.get(position);}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {Node node=mVisibleNodes.get(position);convertView = getContentView(node,position, convertView, parent);return convertView;}public abstract View getContentView(Node node,int position, View convertView, ViewGroup parent);public interface TreeViewOnItemClick{void onTreeItemClick(int position,Node node);}}

我们使用的Adapter

 public class TreeListViewAdapter<T> extends TreeViewBaseAdapter<T> {public TreeListViewAdapter(ListView treeLv, Context context, List<T> datas, int defaultExpandLevel) throws IllegalAccessException, IllegalArgumentException {super(treeLv, context, datas, defaultExpandLevel);}@Overridepublic View getContentView(Node node, int position, View convertView, ViewGroup parent) {ViewHolder holder = null;if (convertView == null) {holder = new ViewHolder();convertView = mInflater.inflate(R.layout.tree_listview_item, parent, false);holder.mItemIv = (ImageView) convertView.findViewById(R.id.mItemIv);holder.mItemTv = (TextView) convertView.findViewById(R.id.mItemTv);convertView.setTag(holder);}else {holder = (ViewHolder) convertView.getTag();}holder.mItemIv.setPadding(node.getLevel()*30, 3, 3, 3);if (node.getIcon() == -1) {holder.mItemIv.setVisibility(View.INVISIBLE);}else {holder.mItemIv.setVisibility(View.VISIBLE);holder.mItemIv.setImageResource(node.getIcon());}holder.mItemTv.setText(node.getName());return convertView;}private static class ViewHolder {ImageView mItemIv;TextView mItemTv;}/*** 动态插入数据* @description：* @author ldm* @date 2015-10-10 上午10:08:03*/public void insertNodeData(int position,String label) {Node node=mVisibleNodes.get(position);int indexOf=mAllNodes.indexOf(node);Node insertNode=new Node(-1, node.getId(), label);insertNode.setParent(node);node.getChildren().add(insertNode);mAllNodes.add(indexOf+1,insertNode);mVisibleNodes=TreeHelperTools.filterVisibleNodes(mVisibleNodes);notifyDataSetChanged();}}

数据处理的工具类：

public class TreeDatasHelperTools {/*** 将用户提供的数据转化成树层级上可用数据* @description：* @date 2015-10-9 下午4:07:24*/public static <T> List<Node> datas2Nodes(List<T> datas) throws IllegalAccessException, IllegalArgumentException {List<Node> nodes = new ArrayList<Node>();Node node = null;for (T t : datas) {int id = -1;int pid = -1;String label = "";// node = new Node();Class clazz = t.getClass();Field[] fields = clazz.getDeclaredFields();// 反射获取类中的字段for (Field field : fields) {if (field.getAnnotation(TreeNodeId.class) != null) {// 根据字段上的注解来获取对应的值field.setAccessible(true);// 在java的反射使用中,如果字段是私有的,那么必须要对这个字段设置才能正常使用，否则报错id = field.getInt(t);}if (field.getAnnotation(TreeNodePid.class) != null) {field.setAccessible(true);pid = field.getInt(t);}if (field.getAnnotation(TreeNodeLabel.class) != null) {field.setAccessible(true);label = (String) field.get(t);}}node = new Node(id, pid, label);nodes.add(node);}// 设置nodes中的父子节点关系for (int i = 0; i < nodes.size(); i++) {Node n = nodes.get(i);for (int j = i + 1; j < nodes.size(); j++) {Node m = nodes.get(j);if (m.getPid() == n.getId()) {// 如果m的父节点pid==n的id，则m是父节点，n是子节点n.getChildren().add(m);m.setParent(n);}else if (m.getId() == n.getPid()) {m.getChildren().add(n);n.setParent(m);}}}// 设置节点图片for (Node n : nodes) {setNodeIcon(n);}return nodes;}/*** 为我们的node数据设置对应的图标* @description：* @date 2015-10-9 下午4:46:29*/private static void setNodeIcon(Node n) {if (n.getChildren().size() > 0 && n.isExpand()) {// 如果有子节点且展开状态n.setIcon(R.drawable.icon_unable);}else if (n.getChildren().size() > 0 && !n.isExpand()) {n.setIcon(R.drawable.icon_enable);}else {n.setIcon(-1);}}public static <T> List<Node> getSortedNodes(List<T> datas, int defaultExpandLevel) throws IllegalAccessException, IllegalArgumentException {List<Node> result = new ArrayList<Node>();List<Node> nodes = datas2Nodes(datas);// 首先获取根节点数据List<Node> rootNodes = getRootNodes(nodes);for (Node node : rootNodes) {addNode(result, node, defaultExpandLevel, 1);}return result;}/*** 获取数据中的所有根节点数据* @description：* @date 2015-10-9 下午5:00:32*/private static List<Node> getRootNodes(List<Node> nodes) {List<Node> root = new ArrayList<Node>();for (Node node : nodes) {if (node.isRoot()) {root.add(node);}}return root;}/*** 获取到可见的节点数据* @description：* @date 2015-10-9 下午5:12:58*/public static List<Node> filterVisibleNodes(List<Node> mAllNodes) {List<Node> nodes = new ArrayList<Node>();for (Node node : mAllNodes) {if (node.isRoot() || node.isParentExpand()) {setNodeIcon(node);nodes.add(node);}}return nodes;}/*** 把一个节点的所有子节点都放入result中* @description：* @date 2015-10-9 下午5:05:57*/private static void addNode(List<Node> result, Node node, int defaultExpandLevel, int currentLevel) {result.add(node);if (defaultExpandLevel >= currentLevel) {node.setExpand(true);}if (node.isLeaf()) { return; }for (int i = 0; i < node.getChildren().size(); i++) {addNode(result, node.getChildren().get(i), defaultExpandLevel, currentLevel + 1);}}}

数据实体Bean:

public class TestBean {@TreeNodeIdprivate int id;//添加对应的注解@TreeNodePidprivate int pid;@TreeNodeLabelprivate String label;private String desc;public TestBean(int id, int pid, String label) {super();this.id = id;this.pid = pid;this.label = label;}public TestBean() {// TODO Auto-generated constructor stub}public int getId() {return id;}public void setId(int id) {this.id = id;}public int getPid() {return pid;}public void setPid(int pid) {this.pid = pid;}public String getLabel() {return label;}public void setLabel(String label) {this.label = label;}public String getDesc() {return desc;}public void setDesc(String desc) {this.desc = desc;}}

数据展示中的Node类，我们可以通过反射+注解把任意实体bean如TestBean映射成我们想要的Node

public class Node {private int id;// 所在节点idprivate int pid = 0;// 父节点的idprivate String name;// 对应的内容private int level;// 所在ListView中树层级private boolean isExpand = false;// 所在节点是否展开private int icon;// 图标iconprivate Node parent;// 父节点Nodeprivate List<Node> children = new ArrayList<Node>();// 对应的子节点数据集public Node() {}public Node(int id, int pid, String name) {this.id = id;this.pid = pid;this.name = name;}public int getId() {return id;}public void setId(int id) {this.id = id;}public int getPid() {return pid;}public void setPid(int pid) {this.pid = pid;}public String getName() {return name;}public void setName(String name) {this.name = name;}/*** 当前节点所在的层级* @description：* @date 2015-10-9 下午4:02:29*/public int getLevel() {return parent == null ? 0 : parent.getLevel() + 1;}public void setLevel(int level) {this.level = level;}public boolean isExpand() {return isExpand;}public void setExpand(boolean isExpand) {this.isExpand = isExpand;if (!isExpand && children.size() > 0) {// 如果当前节点没有展开，则其子节点展开状态也是：没展开for (Node node : children) {node.setExpand(false);}}}public int getIcon() {return icon;}public void setIcon(int icon) {this.icon = icon;}public Node getParent() {return parent;}public void setParent(Node parent) {this.parent = parent;}public List<Node> getChildren() {return children;}public void setChildren(List<Node> children) {this.children = children;}/*** 判断当前节点有没有子节点* @description：* @author ldm* @date 2015-10-9 下午3:59:42*/public boolean isLeaf() {return children.size() == 0;}/*** 是不是根节点* @description：* @author ldm* @date 2015-10-9 下午3:58:15*/public boolean isRoot() {return parent == null;}/*** 当前节点所在父节点是否展开* @description：* @author ldm* @date 2015-10-9 下午3:58:34*/public boolean isParentExpand() {if (parent == null) {return false;}else {return parent.isExpand;}}}

用到的注解类：

@Target(ElementType.FIELD)//定义注解的作用目标：字段、枚举的常量@Retention(RetentionPolicy.RUNTIME)//注解策略：  注解会在class字节码文件中存在，在运行时可以通过反射获取到public @interface TreeNodeId {}

@Target(ElementType.FIELD)//定义注解的作用目标：字段、枚举的常量@Retention(RetentionPolicy.RUNTIME)//注解策略：  注解会在class字节码文件中存在，在运行时可以通过反射获取到public @interface TreeNodeLabel {}``

@Target(ElementType.FIELD)//定义注解的作用目标：字段、枚举的常量
@Retention(RetentionPolicy.RUNTIME)//注解策略： 注解会在class字节码文件中存在，在运行时可以通过反射获取到
public @interface TreeNodePid {
}

ListView的Item对应布局文件：