我不完全理解树结构的确切细节,但这里有一个简单的实现,它采用通用的节点树并将其递归地呈现为 html 列表。
public static string TreeView<T>(IEnumerable<T> rootItems,
Func<T, IEnumerable<T>> childrenProperty,
Func<T, string> itemContent)
{
if (rootItems == null || !rootItems.Any()) return null;
var builder = new StringBuilder();
builder.AppendLine("<ul>");
foreach (var item in rootItems)
{
builder.Append(" <li>").Append(itemContent(item)).AppendLine("</li>");
var childContent = htmlHelper.TreeView(treeId,
childrenProperty(item),
childrenProperty,
itemContent);
if (childContent != null)
{
var indented = childContent.Replace(Environment.NewLine,
Environment.NewLine + " ");
builder.Append(" ").AppendLine(indented);
}
}
builder.Append("</ul>");
return builder.ToString();
}
我使用的节点类相对简单,只有两个属性。
public class Node<T>
{
public Node(T data)
{
Data = data;
Children = new List<Node<T>>();
}
public T Data { get; private set; }
public ICollection<Node<T>> Children { get; private set; }
}
这是一些将树输出到控制台的测试代码。
var Records = new[] {
new Node<string>("one") {
Children = {
new Node<string>("one-one") {
Children = {
new Node<string>("one-one-one"),
new Node<string>("one-one-two"),
new Node<string>("one-one-three")
}
},
new Node<string>("one-two"),
new Node<string>("one-three")
}
},
new Node<string>("two"),
new Node<string>("three")
};
Console.WriteLine(TreeView(Records,
r => r.Children,
r => r.Data));
这是上面代码的结果。
<ul>
<li>one</li>
<ul>
<li>one-one</li>
<ul>
<li>one-one-one</li>
<li>one-one-two</li>
<li>one-one-three</li>
</ul>
<li>one-two</li>
<li>one-three</li>
</ul>
<li>two</li>
<li>three</li>
</ul>