NET 通用方法：把扁平数据转换为树形数据结构【集合】

1.扁平数据为：

Code    ParentCode    Name    Remark
2111011043240001    0    Lv0    
2111011043260002    2111011043240001    Lv0-1    
2111011043260004    2111011043260002    Lv0-1-1    附属信息1:Lv0-1-1
2111011043260010    2111011043260002    Lv0-1-2    附属信息1:Lv0-1-2
2111011043260016    2111011043260002    Lv0-1-3    附属信息1:Lv0-1-3
2111011043260022    2111011043260002    Lv0-1-4    附属信息1:Lv0-1-4
2111011043260028    2111011043260002    Lv0-1-5    附属信息1:Lv0-1-5
2111011043260032    2111011043240001    Lv0-2    
2111011043270034    2111011043260032    Lv0-2-1    附属信息1:Lv0-2-1
2111011043270040    2111011043260032    Lv0-2-2    附属信息1:Lv0-2-2
2111011043270046    2111011043260032    Lv0-2-3    附属信息1:Lv0-2-3
2111011043270050    2111011043240001    Lv0-3    附属信息1:Lv0-3
2111011043270054    2111011043240001    Lv0-5    附属信息1:Lv0-5
2111011043270056    0    Lv1    
2111011043270057    2111011043270056    Lv1-1    
2111011043270059    2111011043270057    Lv1-1-1    附属信息1:Lv1-1-1
2111011043270063    2111011043270056    Lv1-2    附属信息1:Lv1-2
2111011043270067    2111011043270056    Lv1-3    附属信息1:Lv1-3

2.通用方法

        /// <summary>
        /// 通用方法
        /// </summary>
        /// <param name="dbList">源数据集合</param>
        /// <param name="parentCode">父级值</param>
        /// <param name="orderFunc">排序函数</param>
        /// <returns></returns>
        public static List<TreeModel> GetChildrenList(List<DbModel> dbList, string parentCode, Func<IEnumerable<TreeModel>, IEnumerable<TreeModel>> orderFunc = null)
        {
            var treeList = new List<TreeModel>();
            if (dbList.IsNullOrEmpty()) return treeList;

            // 因为框架原因，DbModel不能进行泛型约束，只有TreeModel能直接取到树形相关字段
            var convertTreeList = dbList.MapTo<DbModel, TreeModel>();
            // 筛选数据
            var whereDbList = convertTreeList.Where(x => parentCode.Equals(x.ParentCode));
            // 对数据进行排序
            if (!whereDbList.IsNullOrEmpty() && orderFunc != null) whereDbList = orderFunc(whereDbList);
            if (whereDbList.IsNullOrEmpty()) return treeList;

            foreach (var item in whereDbList)
            {
                var children = GetChildrenList(dbList, item.Code);
                item.Children = children;
                treeList.Add(item);
            }
            return treeList;
        }
    }

3.调用

var treeList = CommonTreeBll<DbModel, TreeModel>.GetChildrenList(dbList, "0", p => p.OrderBy(x => x.Name).ThenBy(x => x.Remark));

4.接口

    public interface ITreeBase<TreeModel>
    {
        /// <summary>
        /// 当前节点主键
        /// </summary>
        string Code { get; set; }

        /// <summary>
        /// 上级节点主键，默认为0[根节点]
        /// </summary>
        string ParentCode { get; set; }

        /// <summary>
        /// 子节点集合
        /// </summary>
        List<TreeModel> Children { get; set; }
    }

5.DbModel & TreeModel

    public partial class DbModel
    {
        // ...
    }

    public class TreeModel : DbModel, ITreeBase<TreeModel >
    {
        public List<TreeModel > Children { get; set; }
    }