Android TreeView如何实现

Android TreeView可以通过自定义Adapter来实现。以下是一个简单的示例代码：

1. 创建一个TreeItem类，用于表示树节点的数据结构：

public class TreeItem {     private String name;     private List<TreeItem> children;      public TreeItem(String name) {         this.name = name;         this.children = new ArrayList<>();     }      public String getName() {         return name;     }      public List<TreeItem> getChildren() {         return children;     }      public void addChild(TreeItem child) {         children.add(child);     } } 

2. 创建一个自定义的TreeAdapter类，继承自BaseExpandableListAdapter，并实现相关方法：

public class TreeAdapter extends BaseExpandableListAdapter {     private List<TreeItem> rootItems;      public TreeAdapter(List<TreeItem> rootItems) {         this.rootItems = rootItems;     }      @Override     public int getGroupCount() {         return rootItems.size();     }      @Override     public int getChildrenCount(int groupPosition) {         return rootItems.get(groupPosition).getChildren().size();     }      @Override     public Object getGroup(int groupPosition) {         return rootItems.get(groupPosition);     }      @Override     public Object getChild(int groupPosition, int childPosition) {         return rootItems.get(groupPosition).getChildren().get(childPosition);     }      @Override     public long getGroupId(int groupPosition) {         return groupPosition;     }      @Override     public long getChildId(int groupPosition, int childPosition) {         return childPosition;     }      @Override     public boolean hasStableIds() {         return true;     }      @Override     public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {         // 实现group视图的绘制         return null;     }      @Override     public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {         // 实现child视图的绘制         return null;     }      @Override     public boolean isChildSelectable(int groupPosition, int childPosition) {         return true;     } } 

3. 在Activity或Fragment中使用TreeView和自定义的TreeAdapter：

TreeView treeView = findViewById(R.id.treeView); List<TreeItem> rootItems = new ArrayList<>(); // 构建树结构 TreeAdapter treeAdapter = new TreeAdapter(rootItems); treeView.setAdapter(treeAdapter); 

通过以上步骤，就可以实现一个简单的Android TreeView。在TreeAdapter中，可以根据需要自定义group和child视图的绘制逻辑，以实现不同的展示效果。