csharp: DataRelation objects to represent a parent/child/Level relationship
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_Load(object sender, EventArgs e)
{
var sections = new List<Section>
{
new Section { Id = 1, Name = "中国", ParentID = 0 },
new Section { Id = 2, Name = "江西", ParentID = 1 },
new Section { Id = 3, Name = "江苏", ParentID = 1 },
new Section { Id = 4, Name = "南京", ParentID = 3 },
new Section { Id = 5, Name = "南昌", ParentID = 2 },
new Section { Id = 6, Name = "东湖区", ParentID = 5 },
new Section { Id = 7, Name = "广东", ParentID = 1 },
new Section { Id = 8, Name = "深圳", ParentID = 7 },
new Section { Id = 9, Name = "罗湖区涂聚文", ParentID = 8 }
};
//sections = sections.OrderBy(x => x.ParentID).ThenBy(x => x.Name).ToList();
//var stack = new Stack<Section>();
//// Grab all the items without parents
//foreach (var section in sections.Where(x => x.ParentID == default(int)).Reverse())
//{
// stack.Push(section);
// sections.RemoveAt(0);
//}
//var output = new List<Section>();
//while (stack.Any())
//{
// var currentSection = stack.Pop();
// var children = sections.Where(x => x.ParentID == currentSection.Id).Reverse();
// foreach (var section in children)
// {
// stack.Push(section);
// sections.Remove(section);
// }
// output.Add(currentSection);
//}
//sections = output;
List<MySection> mys = MenuHelper.GetMyMenuCollection(sections);
//ResolveDDL<MySectionMenu>(mys);
for (int i = 0; i < mys.Count; i++)
{
Response.Write(string.Format("ID:{0} ParentID: {1} TreeLevel: {2} Name:{3}<br/>", mys[i].Id, mys[i].ParentID, mys[i].TreeLevel,mys[i].Name));
}
}
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="mys"></param>
protected void ResolveDDL<T>(List<T> mys) where T : MyBaseSection, new()
{
ResolveDDL<T>(mys, -1, true);
}
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="mys"></param>
/// <param name="currentId"></param>
protected void ResolveDDL<T>(List<T> mys, int currentId) where T : MyBaseSection, new()
{
ResolveDDL<T>(mys, currentId, true);
}
/// <summary>
/// 将一个树型结构放在一个下列列表中可供选择
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="currentId"></param>
/// <param name="mys"></param>
protected void ResolveDDL<T>(List<T> mys, int currentId, bool addRootNode) where T : MyBaseSection, new()
{
if (addRootNode)
{
// 所有节点的TreeLevel加一，然后添加根节点
foreach (T my in mys)
{
my.TreeLevel += 1;
}
T root = new T();
root.Name = "--根节点--";
root.Id = 0;
root.TreeLevel = 0;
mys.Insert(0, root);
}
// currentId==-1表示当前节点不存在
if (currentId != -1)
{
// 本节点不可点击（也就是说当前节点不可能是当前节点的父节点）
// 并且本节点的所有子节点也不可点击，你想如果当前节点跑到子节点的子节点，那么这些子节点就从树上消失了
bool startChileNode = false;
int startTreeLevel = 0;
foreach (T my in mys)
{
if (my.Id == currentId)
{
startTreeLevel = my.TreeLevel;
my.Enabled = false;
startChileNode = true;
}
else
{
if (startChileNode)
{
if (my.TreeLevel > startTreeLevel)
{
my.Enabled = false;
}
else
{
startChileNode = false;
}
}
}
}
}
}
}
/// <summary>
/// /
/// </summary>
public class Section
{
public int Id { get; set; }
public string Name { get; set; }
public int ParentID { get; set; }
}
/// <summary>
///
/// </summary>
public class MySection
{
public int Id { get; set; }
public string Name { get; set; }
public int ParentID { get; set; }
public int TreeLevel { get; set; }
}
/// <summary>
///
/// </summary>
public class MySectionMenu : MyBaseSection
{
}
/// <summary>
///
/// </summary>
public class MyBaseSection
{
public int Id
{
get;
set;
}
public int ParentId
{
get;
set;
}
public string Name
{
get;
set;
}
/// <summary>
/// 本菜单在树形结构中层级（从0开始）
/// </summary>
public int TreeLevel
{
get;
set;
}
/// <summary>
/// 是否可用（默认true）
/// </summary>
public bool Enabled
{
get;
set;
}
/// <summary>
/// 是否叶子节点（默认false）
/// </summary>
public bool IsTreeLeaf
{
get;
set;
}
}
/// <summary>
///
/// </summary>
public class MenuHelper
{
/// <summary>
///
/// </summary>
/// <param name="oldMenus"></param>
/// <returns></returns>
public static List<MySection> GetMyMenuCollection(List<Section> oldMenus)
{
List<MySection> newMenus = new List<MySection>();
ResolveMenuCollection(oldMenus, newMenus, 0, 0);
return newMenus;
}
/// <summary>
///
/// </summary>
/// <param name="oldMenus"></param>
/// <param name="newMenus"></param>
/// <param name="parentId"></param>
/// <param name="level"></param>
/// <returns></returns>
private static int ResolveMenuCollection(List<Section> oldMenus, List<MySection> newMenus, int parentId, int level)
{
int count = 0;
foreach (Section menu in oldMenus)
{
if (menu.ParentID == parentId)
{
count++;
MySection my = new MySection();
newMenus.Add(my);
my.TreeLevel = level;
my.Id = menu.Id;
my.Name = menu.Name;
my.ParentID = menu.ParentID;
level++;
int childCount = ResolveMenuCollection(oldMenus, newMenus, menu.Id, level);
level--;
}
}
return count;
}
}
显示结果：
ID:1 ParentID: 0 TreeLevel: 0 Name:中国
ID:2 ParentID: 1 TreeLevel: 1 Name:江西
ID:5 ParentID: 2 TreeLevel: 2 Name:南昌
ID:6 ParentID: 5 TreeLevel: 3 Name:东湖区
ID:3 ParentID: 1 TreeLevel: 1 Name:江苏
ID:4 ParentID: 3 TreeLevel: 2 Name:南京
ID:7 ParentID: 1 TreeLevel: 1 Name:广东
ID:8 ParentID: 7 TreeLevel: 2 Name:深圳
ID:9 ParentID: 8 TreeLevel: 3 Name:涂聚文