无限分级Repeater递归实现：读取一次数据库，使用LINQ2SQL技术，支持排序&显示隐藏
时间：2022-03-14 03:00
预览效果图：
数据库结构：
id(int) classname(string) parentid(int) sort(int用于显示与排序)
1 家居 0 1
2 家电 0 2
3 沙发 1 1
4 某... 3 1
...
10 ...红色 4 1
注：
parentid 父节点ID
sort 用于隐藏或显示 兼排序功能
前台：
<asp:Repeater ID="rep" runat="server" onitemdatabound="rep_ItemDataBound">
<HeaderTemplate></HeaderTemplate>
<ItemTemplate></ItemTemplate>
<FooterTemplate></FooterTemplate>
</asp:Repeater>
后台：
代码public partial class 递归2 : System.Web.UI.Page
{
public List<cmodel> list;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
rules r = new rules();
list = r.getlist();//读取数据库
this.rep.DataSource = list.Where(x => x.parentid == 0).ToList();//LINQ2OBJECT
this.rep.DataBind();
}
}
protected void rep_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Header)
{
Literal l = new Literal();
l.ID = "ul";
l.Text="<ul>";
e.Item.Controls.Add(l);
}
else if (e.Item.ItemType == ListItemType.Footer)
{
Literal l = new Literal();
l.ID = "ul2";
l.Text = "</ul>";
e.Item.Controls.Add(l);
}
else if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
int id = (int)DataBinder.Eval(e.Item.DataItem, "id");
Literal li1 = new Literal();
li1.ID = "li1";
li1.Text = "<li>";
e.Item.Controls.Add(li1);
Literal name = new Literal();
name.ID = "n";
name.Text = DataBinder.Eval(e.Item.DataItem, "classname").ToString();
e.Item.Controls.Add(name);
List<cmodel> temp = list.Where(x => x.parentid == id).ToList();//LINQ2OBJECT
if (temp.Count > 0)
{
Repeater r = new Repeater();
TemplateBuilder tb = new TemplateBuilder();
tb.AppendLiteralString("");
r.HeaderTemplate = tb;
r.FooterTemplate = tb;
r.ItemTemplate = tb;
r.ItemDataBound += new RepeaterItemEventHandler(rep_ItemDataBound); //递归核心
r.DataSource = temp;
r.DataBind();
e.Item.Controls.Add(r);
}
Literal li2 = new Literal();
li2.ID = "li2";
li2.Text = "</li>";
e.Item.Controls.Add(li2);
}
}
}
使用到的类：
代码public class rules{
DataClasses1DataContext dc = new DataClasses1DataContext();
public List<cmodel> getlist()
{
var q = from x in dc.ClassFJ
where x.sort > 0 //用于控制显示隐藏
orderby x.sort //兼职排序功能
select new cmodel
(
x.id,
x.className,
x.parentid
);
return q.ToList<cmodel>();
}
}
public class cmodel
{
public cmodel(int i,string n,int p)
{
id = i;
classname = n;
parentid = p;
}
public int id { get; set; }
public string classname { get; set; }
public int parentid { get; set; }
}抛砖引玉，话不多讲。
