web api+递归树型结构

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using SqlSugar;
using Models;
using WebApplication.Dao;
using System.Text;

namespace WebApplication.Controllers
{
    /// <summary>
    /// 分类接口
    /// </summary>
    public class classificationController : ApiController
    {
        /// <summary>
        /// 获取分类列表(条件查询，分页) http://192.168.2.177:1222/api/classification/GetclassificationListPage?pageIndex=1&pageSize=10&status=2&title=
        /// </summary>
        /// <param name="pageIndex">分页索引</param>
        /// <param name="pageSize">分页大小</param>
        /// <param name="status">状态：0:下线 1：上线  -1：失效,默认传入2获取所有数据</param>
        /// <param name="title"></param>
        /// <returns></returns>
        [Route("api/classification/GetclassificationListPage")]
        [HttpGet]
        public string GetclassificationListPage(int pageIndex, int pageSize, int status, string title)
        {
            try
            {
                using (var db = SugarDao.GetInstance())
                {

                    var qable = db.Queryable<tb_classification>();
                    var dataCountTable = db.Queryable<tb_classification>();

                    if (status != )
                    {
                        qable = qable.Where(i => i.status == status);
                        dataCountTable = dataCountTable.Where(i => i.status == status);
                    }
                    if (status == )
                    {
                        dataCountTable = dataCountTable.Where(i => i.status != status);
                    }
                    if (!string.IsNullOrEmpty(title))
                    {
                        qable = qable.Where(i => i.title.Contains(title));
                        dataCountTable = dataCountTable.Where(i => i.title.Contains(title));
                    }

                    var data = qable.OrderBy(it => it.createtime, OrderByType.Asc).ToPageList(pageIndex, pageSize);

                    var dataCount = dataCountTable.ToList().Count;

                    if (data.Count > )
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据成功", Data = data, Count = dataCount });
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败", Data = data, Count = dataCount });
                    }

                }
            }
            catch (Exception ex)
            {
                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败,原因为:" + ex.Message });
            }
        }

        /// <summary>
        /// 获取分类数据，不分页 http://192.168.2.177:1222/api/classification/GetclassificationList?status=2&title=
        /// </summary>
        /// <param name="status"></param>
        /// <param name="title"></param>
        /// <returns></returns>
        [Route("api/classification/GetclassificationList")]
        [HttpGet]
        public string GetclassificationList(int status, string title)
        {
            try
            {
                using (var db = SugarDao.GetInstance())
                {
                    var qable = db.Queryable<tb_classification>();
                    if (status != )
                    {
                        qable = qable.Where(i => i.status == status);
                    }
                    if (!string.IsNullOrEmpty(title))
                    {
                        qable = qable.Where(i => i.title.Contains(title));
                    }
                    var data = qable.OrderBy(it => it.createtime, OrderByType.Asc).ToList();
                    var dataCount = db.Queryable<tb_classification>().Where(it => it.status != status).ToList().Count;
                    if (data.Count > )
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据成功", Data = data, Count = dataCount });
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败", Data = data, Count = dataCount });
                    }

                }
            }
            catch (Exception ex)
            {
                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败,原因为:" + ex.Message });
            }
        }

        /// <summary>
        /// 根据id得到对象 http://192.168.2.177:1222/api/classification/GetclassificationModel?id=1
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        [Route("api/classification/GetclassificationModel")]
        [HttpGet, HttpPost]
        public string GetclassificationModel(int id)
        {
            try
            {
                using (var db = SugarDao.GetInstance())
                {
                    if (id != )
                    {
                        var classification = db.Queryable<tb_classification>().Single(it => it.id == id);
                        if (classification != null)
                        {
                            return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据成功", Data = classification });
                        }
                        else
                        {
                            return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败", Data = classification });
                        }
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败,无法找到id为:" + id + "的数据", });
                    }

                }
            }
            catch (Exception ex)
            {
                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据失败,原因为:" + ex.Message });
            }
        }
        /// <summary>
        /// 新增分类 http://192.168.2.177:1222/api/classification/Postclassification
        /// </summary>
        /// <param name="classification"></param>
        [Route("api/classification/Postclassification")]
        [HttpPost]
        public string Postclassification(tb_classification classification)
        {
            try
            {
                classification.createtime = DateTime.Parse(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
                using (var db = SugarDao.GetInstance())
                {
                    object result = db.Insert<tb_classification>(classification);
                    if (Convert.ToInt64(result) > )
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "添加成功" });
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "添加失败" });
                    }
                }
            }
            catch (Exception ex)
            {

                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "添加失败,原因为:" + ex.Message });
            }
        }
        /// <summary>
        /// 修改分类
        /// </summary>
        /// <param name="id"></param>
        /// <param name="value"></param>
        [Route("api/classification/Putclassification")]
        [HttpPost]
        public string Putclassification(tb_classification classification)
        {
            try
            {
                classification.createtime = DateTime.Parse(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
                using (var db = SugarDao.GetInstance())
                {
                    bool result = db.Update<tb_classification>(classification, it => it.id == classification.id);
                    if (result == true)
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "更新成功" });
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "更新失败" });
                    }
                }
            }
            catch (Exception ex)
            {
                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "更新失败,原因为:" + ex.Message });
            }
        }
        /// <summary>
        /// 删除 http://192.168.2.177:1222/api/classification/Deleteclassification?ids=4,5
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        [Route("api/classification/Deleteclassification")]
        [HttpGet, HttpPost]
        public string Deleteclassification(string ids)
        {
            try
            {
                string[] input = ids.Split(',');
                int[] output = Array.ConvertAll<string, int>(input, delegate (string s) { return int.Parse(s); });

                using (var db = SugarDao.GetInstance())
                {
                    bool result = db.Delete<tb_classification, int>(output);
                    if (result == true)
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "删除成功" });
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "删除失败" });
                    }
                }
            }
            catch (Exception ex)
            {
                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "删除失败,原因为:" + ex.Message });
            }
        }

        /// <summary>
        /// 更新状态 http://192.168.2.177:1222/api/classification/UpdateStatus?status=0&ids=2,7
        /// </summary>
        /// <param name="status">状态：0:下线 1：上线  -1：失效 </param>
        /// <param name="ids"></param>
        /// <returns></returns>
        [Route("api/classification/UpdateStatus")]
        [HttpGet]
        public string UpdateStatus(int status, string ids)
        {
            try
            {
                string[] input = ids.Split(',');
                int[] output = Array.ConvertAll<string, int>(input, delegate (string s) { return int.Parse(s); });
                using (var db = SugarDao.GetInstance())
                {
                    bool result = db.Update<tb_classification, int>(new { status = status }, output);
                    if (result == true)
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "状态更改成功" });
                    }
                    else
                    {
                        return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "状态更改失败" });
                    }
                }
            }
            catch (Exception ex)
            {
                return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "状态更改失败,原因为:" + ex.Message });
            }
        }

        string result = string.Empty;
        /// <summary>
        /// 分类树形结构  http://192.168.2.177:1222/api/classification/GetclassificationTree
        /// </summary>
        /// <returns></returns>
        [Route("api/classification/GetclassificationTree")]
        [HttpGet]
        public string GetclassificationTree()
        {

            WebApplication.Controllers.TreeMethod tm = new TreeMethod();

            // 找到所有的父节点
            List<TreeEntity> treeList1 = tm.findAllParents();

            if (treeList1 != null)
            {
                for (int i = ; i < treeList1.Count; i++)
                {
                    TreeEntity tree = treeList1[i];
                    // 打印父节点
                    result += "|--" + tree.name;
                    // 绑定孩子
                    result+=tm.BindChildByParent(tree.id, "");
                }
            }
            else
            {
                result += "没有数据！";
            }
            return SqlSugar.JsonConverter.Serialize(new { Result = , Msg = "获取数据成功",Data= result });
        }
    }
    public class TreeEntity
    {
        public string id { get; set; }
        public string name { get; set; }
        public string pid { get; set; }
    }
    internal class TreeMethod
    {
        /// <summary>
        /// 找到所有的父节点
        /// </summary>
        /// <returns></returns>
        public List<TreeEntity> findAllParents()
        {
            List<TreeEntity> treeList = new List<TreeEntity>();

            using (var db = SugarDao.GetInstance())
            {
                var list = db.Queryable<tb_classification>().Where(it => it.pid ==  && it.status==).ToList();
                if (list.Count > )
                {
                    for (int i = ; i < list.Count; i++)
                    {
                        TreeEntity myTree = new TreeEntity();
                        myTree.id = list[i].id.ToString();
                        myTree.name = list[i].title;
                        myTree.pid = list[i].pid.ToString();
                        treeList.Add(myTree);
                    }
                }
            }
            return treeList;
        }

        /// <summary>
        /// 根据父节点找到所有的子节点
        /// </summary>
        /// <param name="pid"></param>
        /// <returns></returns>
        public List<TreeEntity> findChildByPid(string pid)
        {
            int p_id = Convert.ToInt32(pid);
            List<TreeEntity> treeList = new List<TreeEntity>();

            using (var db = SugarDao.GetInstance())
            {
                var list = db.Queryable<tb_classification>().Where(it => it.pid == p_id&&it.status==).ToList();
                if (list.Count > )
                {
                    for (int i = ; i < list.Count; i++)
                    {
                        TreeEntity myTree = new TreeEntity();
                        myTree.id = list[i].id.ToString();
                        myTree.name = list[i].title;
                        myTree.pid = list[i].pid.ToString();
                        treeList.Add(myTree);
                    }
                }
            }
            return treeList;
        }
        /// <summary>
        /// 查看是否存在子节点
        /// </summary>
        /// <param name="pid"></param>
        /// <returns></returns>
        public bool HasChild(string pid)
        {
            int p_id = Convert.ToInt32(pid);
            int count = ;
            bool flag = false;
            using (var db = SugarDao.GetInstance())
            {
                var list = db.Queryable<tb_classification>().Where(it => it.pid == p_id&it.status==).ToList();

                for (int i = ; i < list.Count; i++)
                {
                    count++;
                }
                if (count > )
                {
                    flag = true;
                }
            }
            return flag;
        }
        string Tree = string.Empty;
        /// <summary>
        /// 使用递归拼接父节点的子节点
        /// </summary>
        /// <param name="pid"></param>
        /// <param name="prefix"></param>
        public string BindChildByParent(string pid, string prefix)
        {

            if (this.HasChild(pid))
            {
                // 得到当前父节点下的所有孩子
                List<TreeEntity> list = this.findChildByPid(pid);
                // 循环打印当前父节点下的孩子
                for (int i = ; i < list.Count; i++)
                {
                    Tree += "|----" + prefix + list[i].name;
                    if (this.HasChild(list[i].id))
                    {
                        this.BindChildByParent(list[i].id, "--");
                    }
                }
            }
            return Tree;
        }
    }
}