首先建立模型類Menus

public class Menus
{
    //選單Id
    public int Id { get; set; }
    //選單名
    public string MenuName { get; set; }
    //父節點Id
    public int ParentId { get; set; }
}

窗體中放入button跟TreeView控制元件

宣告全域性變數

private static List<Menus> menus;

新增按鈕事件

private void button1_Click(object sender,EventArgs e)
{
    menus 
 
= new List<Menus>();
    menus.Add(new Menus { Id = 1,MenuName = "基礎設定",ParentId = 0 });
    menus.Add(new Menus { Id = 2,MenuName = "採購管理",ParentId = 0 });
    menus.Add(new Menus { Id = 3,MenuName = "系統設定",ParentId = 1 });
    menus.Add(new Menus { Id = 4,MenuName = "使用者管理",ParentId = 1 });
    menus.Add(
 
new Menus { Id = 5,MenuName = "採購訂單",ParentId = 2 });
    menus.Add(new Menus { Id = 6,MenuName = "採購入庫",ParentId = 2 });
    menus.Add(new Menus { Id = 7,MenuName = "使用者",ParentId = 4 });
    menus.Add(new Menus { Id = 8,MenuName = "採購退貨",ParentId = 2 });
    menus.Add(new Menus { Id = 9,MenuName = "
 
使用者組",ParentId = 4 });
    menus.Add(new Menus { Id = 10,MenuName = "許可權管理",ParentId = 4 });
    
    //首先查出頂級選單，迴圈新增
    IEnumerable<Menus> menu = from m in menus where m.ParentId == 0 orderby m.ParentId select m;

    foreach (var item in menu)
    {
        TreeNode node = new TreeNode();
        node.Tag = item;
        node.Text = item.MenuName;
        treeView1.Nodes.Add(node);
        //將當前節點作為引數傳入子節點
        AddChildMenu(node);
    }

}

子節點遞迴實現

private void AddChildMenu(TreeNode node)
{
    Menus menu = new Menus();
    menu = (Menus)node.Tag;   //將父節點轉為Model
    //查出當前子節點中所有同父節點Id一樣的資料
    IEnumerable<Menus> childMenu = from m in menus where m.ParentId == menu.Id orderby m.Id select m;
    foreach (var item in childMenu)
    {
        TreeNode childNode = new TreeNode();
        childNode.Tag = item;
        childNode.Text = item.MenuName;
        node.Nodes.Add(childNode);  //新增子節點
        AddChildMenu(childNode);    //遞迴呼叫自己，直到父節點新增所有子節點結束
    }
}

效果展示