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最新推荐文章于 2022-01-14 09:39:28 发布

yingjiell

最新推荐文章于 2022-01-14 09:39:28 发布

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文章标签： string null tree

本文介绍了一种将扁平化的数据表转换成树状结构的方法，通过递归地获取顶层和子级目录，并添加深度符号来表示层级关系。支持自定义排序及选择是否在顶级目录添加深度标记。

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/// <summary>
        /// 构造函数
        /// </summary>
        public DataTableTree2()
        {

}

int depth = 0;//深度变量
DataTable dt_Tree = new DataTable();//存放处理后数据的DataTable

        #region 属性
        private DataTable _tableName = null;
        /// <summary>
        /// 源数据表(必填)
        /// </summary>
        public DataTable ATableName
        {
            set { _tableName = value; }
            get { return _tableName; }
        }

        private string _parentIDFiled = null;
        /// <summary>
        /// 父级字段即ParentID(必填)
        /// </summary>
        public string BParentIDFiled
        {
            set { _parentIDFiled = value; }
            get { return _parentIDFiled; }
        }

        private string _sortStyle = null;
        /// <summary>
        /// 排序方式，(可选)默认为升序，不填则默认以主键进行升序排列
        /// </summary>
        public string CSortStyle
        {
            set { _sortStyle = value; }
            get { return _sortStyle; }
        }

        private string _keyFiled = null;
        /// <summary>
        /// 主键字段(必填)
        /// </summary>
        public string DKeyFiled
        {
            set { _keyFiled = value; }
            get { return _keyFiled; }
        }

        private string _dataTextFiled = null;
        /// <summary>
        /// 深度列的文本字段名(必填)
        /// </summary>
        public string EDataTextFiled
        {
            set { _dataTextFiled = value; }
            get { return _dataTextFiled; }
        }

        private string _depthSign = null;
        /// <summary>
        /// 深度符号(必填)
        /// </summary>
        public string FDepthSign
        {
            set { _depthSign = value; }
            get { return _depthSign; }
        }

        private bool _parentIsAddDepthSign = true;
        /// <summary>
        /// 第一级是否添加深度符号,(可选)默认已添加深度符号
        /// </summary>
        public bool GParentIsAddDepthSign
        {
            set { _parentIsAddDepthSign = value; }
            get { return _parentIsAddDepthSign; }
        }
        #endregion

        /// <summary>
        /// 获取顶级目录
        /// </summary>
        /// <returns>DataTable</returns>
        public DataTable GetParentTree()
        {
            dt_Tree = ATableName.Clone();
            string strSort = null;
            if (!StrIsNull(CSortStyle))
            {
                strSort = CSortStyle;
            }
            else
            {
                strSort = DKeyFiled + " asc";
            }
            DataRow[] dr = ATableName.Select(BParentIDFiled + "=0", strSort);
            foreach (DataRow drrr in dr)
            {
                if (GParentIsAddDepthSign)
                {
                    drrr[EDataTextFiled] = FDepthSign + drrr[EDataTextFiled].ToString();
                }
                else
                {
                    drrr[EDataTextFiled] = drrr[EDataTextFiled].ToString();
                }
                dt_Tree.Rows.Add(drrr.ItemArray);
                depth = 0;
                if (IsHaveChild(BParentIDFiled, drrr[DKeyFiled].ToString()))
                {
                    GetChildTree(drrr[DKeyFiled].ToString());
                }
            }
            return dt_Tree;
        }

        /// <summary>
        /// 获取子级目录
        /// </summary>
        /// <param name="ClassID">主键ID值</param>
        private void GetChildTree(string ClassID)
        {
            DataTable dt_ChiledTree = new DataTable();
            dt_ChiledTree = ATableName.Clone();
            ++depth;//深度变量
            string strSort = null;
            if (!StrIsNull(CSortStyle))
            {
                strSort = CSortStyle;
            }
            else
            {
                strSort = DKeyFiled + " asc";
            }
            DataRow[] dr = ATableName.Select(BParentIDFiled + "=" + ClassID, strSort);
            foreach (DataRow drrr in dr)
            {
                drrr[EDataTextFiled] = AddDepthSign(depth) + drrr[EDataTextFiled].ToString();
                dt_Tree.Rows.Add(drrr.ItemArray);
                if (IsHaveChild(BParentIDFiled, drrr[DKeyFiled].ToString()))
                {
                    GetChildTree(drrr[DKeyFiled].ToString());
                    depth--;
                }
            }
        }

        /// <summary>
        /// 获取深度符号
        /// </summary>
        /// <param name="depthVal">深度</param>
        /// <returns>深度级数</returns>
        private string AddDepthSign(int depthVal)
        {
            StringBuilder strAdd = new StringBuilder();
            if (GParentIsAddDepthSign)
            {
                for (int i = 0; i <= depthVal; i++)
                {
                    strAdd.Append(FDepthSign);
                }
            }
            else
            {
                for (int i = 0; i < depthVal; i++)
                {
                    strAdd.Append(FDepthSign);
                }
            }
            return strAdd.ToString();
        }

        /// <summary>
        /// 判断字符串是否为空
        /// </summary>
        /// <param name="checkStr">检测字符串</param>
        /// <returns>true or false</returns>
        private bool StrIsNull(string checkStr)
        {
            bool b = true;
            if (!string.IsNullOrEmpty(checkStr) && checkStr != "")
            {
                b = false;
            }
            return b;
        }

        /// <summary>
        /// 是否包含子栏目
        /// <param name="ParentIDFiled">父节点字段名</param>
        /// <param name="ClassID">父节点栏目ID,多个ID时用,号隔开</param>
        /// </summary>
        /// <returns>true or false</returns>
        private bool IsHaveChild(string ParentIDFiled, string ClassID)
        {
            bool r = false;
            if (ATableName.Select(ParentIDFiled + " in (" + ClassID + ") ").Length > 0)
            {
                r = true;
            }
            return r;
        }