中以一种简单的方式做到这一点
在
我的表格如下
ID | Reason | PrID
-----------------
1 abc null
2 dhe null
3 aerc 1
4 dwes 2
5 adfje 1
我有班级
public class Reason
{
public int Id { get; set; }
public string Reson{ get; set; }
public List<SecondryReason> SecReason{ get; set; }
public int? PrimaryId { get; set; }
}
public class SecondryReason
{
public int Id { get; set; }
public string Reason { get; set; }
public int PrimaryReasonId { get; set; }
}
我希望以层次结构级别显示如果Prid为null需要将其视为父母留下所有孩子
我正在尝试linq,无法实现这一目标
建议我在Linq
so:您有一个列表/列举的类型,其中秘密列表属性为null。然后,使用LINQ您想要一个列表,这是唯一的"根"原因,但是子季节被放在列表中,但是作为类型的SensicReason?如果是这样,我找到了这样做的方法(linq和foreach):
static IEnumerable<Reason> GetReasonsGrouped(List<Reason> reasons)
{
var result = reasons.Where(x => x.PrimaryId == null);
foreach (var item in result)
{
item.SecReason = reasons.Where(x => x.PrimaryId == item.Id)
.Select(x => new SecondryReason()
{ Id = x.Id,
ReasonName = x.ReasonName,
PrimaryReasonId = item.Id
})
.ToList();
}
return result;
}
或只是linq,但很难阅读:
var result = reasons.Where(x => x.PrimaryId == null)
.Select(x =>
{
x.SecReason = reasons.Where(r => x.PrimaryId == x.Id)
.Select(r => new SecondryReason()
{
Id = r.Id,
ReasonName = x.ReasonName,
PrimaryReasonId = x.Id
})
.ToList();
return x;
});
public class Reason
{
public int Id { get; set; }
public string Reson { get; set; }
public List<Reason> SecReason { get; set; }
public int? PrimaryId { get; set; }
//Adds child to this reason object or any of its children/grandchildren/... identified by primaryId
public bool addChild(int primaryId, Reason newChildNode)
{
if (Id.Equals(primaryId))
{
addChild(newChildNode);
return true;
}
else
{
if (SecReason != null)
{
foreach (Reason child in SecReason)
{
if (child.addChild(primaryId, newChildNode))
return true;
}
}
}
return false;
}
public void addChild(Reason child)
{
if (SecReason == null) SecReason = new List<Reason>();
SecReason.Add(child);
}
}
private List<Reason> GetReasonsHierarchy(List<Reason> reasons)
{
List<Reason> reasonsHierarchy = new List<Reason>();
foreach (Reason r in reasons)
{
bool parentFound = false;
if (r.PrimaryId != null)
{
foreach (Reason parent in reasonsHierarchy)
{
parentFound = parent.addChild(r.PrimaryId.Value, r);
if (parentFound) break;
}
}
if (!parentFound) reasonsHierarchy.Add(r);
}
return reasonsHierarchy;
}