c# this关键字用法代码详解

给EPList创建索引，并添加数据

private EPList<SysDepartInfo> GetEPListData()
{
  EPList<SysDepartInfo> eplist = new EPList<SysDepartInfo>();
  eplist.CreateIndex(new string[] { "ParentId" });
  string sql = "select Id,ParentId,Code,Name from SysDepart";
  SqlHelper.ExecuteReader(sql, null, (reader) =>
  {
    SysDepartInfo record = new SysDepartInfo();
    record.Id = Convert.ToString(reader["Id"]);
    record.ParentId = Convert.ToString(reader["ParentId"]);
    record.Code = Convert.ToString(reader["Code"]);
    record.Name = Convert.ToString(reader["Name"]);
    eplist.Add(record);
  });
  return eplist;
}

给EPList创建索引，并添加数据

private EPList<SysDepartInfo> GetEPListData()
{
EPList<SysDepartInfo> eplist = new EPList<SysDepartInfo>();
eplist.CreateIndex(new string[] { "ParentId" });
string sql = "select Id,ParentId,Code,Name from SysDepart";
SqlHelper.ExecuteReader(sql, null, (reader) =>
{
SysDepartInfo record = new SysDepartInfo();
record.Id = Convert.ToString(reader["Id"]);
record.ParentId = Convert.ToString(reader["ParentId"]);
record.Code = Convert.ToString(reader["Code"]);
record.Name = Convert.ToString(reader["Name"]);
eplist.Add(record);
});
return eplist;
}

给EPList创建索引，并添加数据

/// <summary>
/// 获取子节点
/// </summary>
/// <param name="data"></param>
/// <param name="parentId"></param>
private IEnumerable<TreeInfo> CreateChildren(EPList<SysDepartInfo> data, TreeInfo node)
{
  string id = node == null ? "0" : node.id;
  List<TreeInfo> childNodes = new List<TreeInfo>();
  // ParentId字段上创建了索引，所以这里就可以通过索引值直接取出下一层子节点数据，避免Linq查询引发的效率问题
  var indexValues = new string[] { "ParentId:" + id };
  var childData = data[indexValues];
  childData.ForEach(record =>
  {
    var childNode = new TreeInfo
    {
      id = record.Id,
      text = record.Code + " " + record.Name
    };
    childNodes.Add(childNode);
    childNode.children = CreateChildren(data, childNode);
  });
  return childNodes.OrderBy(record => record.text);
}

通过索引高效查询数据

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