我目前正在尝试创建一个实现的类,IEnumerable<T>
以便从通过 ParentId 属性相互引用的对象的平面列表构造层次结构。我想为此编写一个流畅的界面,这样我就可以做这样的事情
IEnumerable<Tab> tabs = GetTabs();
IEnumerable<TabNode> tabNodes = tabs.AsHierarchy().WithStartLevel(2).WithMaxDepth(5);
所以,关于 yield 语句,我想知道我是否可以在课堂上做这样的事情NodeHierarchy : IEnumerable<TabNode>
:
private IEnumerable<TabNode> _nodes;
public NodeHierarchy(IEnumerable<Tab> tabs)
{
_nodes = CreateHierarchy(tabs);
}
public IEnumerable<TabNode> CreateHierarchy(IEnumerable<Tab> tabs)
{
/* About this block: I'm trying to find the top level
nodes of the first tab collection, maybe this is done poorly? */
var tabIds = tabs.Select(t => t.TabID);
IEnumerable<TabNode> nodes = from tab in tabs
where !tabIds.Contains(tab.ParentId)
select new TabNode {
Tab = node,
ChildNodes = CreateHierarchy(tabs, node.TabID, 1),
Depth = 1 };
return nodes;
}
或者我是否必须做这样的事情:
private IEnumerable<TabNode> _nodes;
public NodeHierarchy(IEnumerable<Tab> tabs)
{
_nodes = CreateHierarchy(tabs);
}
public IEnumerable<TabNode> CreateHierarchy(IEnumerable<Tab> tabs)
{
var tabIds = tabs.Select(t => t.TabID);
IEnumerable<Tab> startingNodes = from tab in tabs
where !tabIds.Contains(tab.ParentId)
select tab;
foreach(Tab node in startingNodes)
{
yield return
new TabNode()
{
Tab = node,
ChildNodes = CreateHierarchy(tabs, node.TabID, 1),
Depth = 1
};
}