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：

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);
    }
}

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;
    }
}

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。

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