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>();

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.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() {


@Override
public 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() {


@Override
public 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() {

@Override
public 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() {


@Override
public 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();
}
}


@Override
public int getCount() {
// TODO Auto-generated method stub
return mVisibleNodes.size();
}


@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return mVisibleNodes.get(position);
}


@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}


@Override
public 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);
}


@Override
public 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 {
@TreeNodeId
private int id;//添加对应的注解
@TreeNodePid
private int pid;
@TreeNodeLabel
private 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id
private int pid = 0;// 父节点的id
private 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icon
private Node parent;// 父节点Node
private 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：