C# 编程嵌套列表
我正在尝试使用ListView控件在Asp.Net/C#中创建嵌套列表。我看了很多例子,但我似乎没有任何意义 以下是模式:C# 编程嵌套列表,c#,asp.net,listview,repeater,C#,Asp.net,Listview,Repeater,我正在尝试使用ListView控件在Asp.Net/C#中创建嵌套列表。我看了很多例子,但我似乎没有任何意义 以下是模式: <ul> <li>Item 1 - level 1</li> <li>Item 2 - level 1</li> <li>Item 3 - level 1 <ul> <li>Item 1 - level 2</
<ul>
<li>Item 1 - level 1</li>
<li>Item 2 - level 1</li>
<li>Item 3 - level 1
<ul>
<li>Item 1 - level 2</li>
<li>Item 2 - level 2</li>
<li>Item 3 - level 2</li>
</ul>
</li>
</ul>
- 项目1-第1级
- 项目2-第1级
- 项目3-第1级
- 项目1-第2级
- 项目2-第2级
- 项目3-第2级
我创建了一个列表,它使用一个级别,因此它没有正确地嵌套在html中-只是一个由
标记组成的平面列表
不过,我想做些改变
只有一个级别将有一个子菜单-并且一些级别1的项目可能没有任何子项目-因此我正在寻找一个可以呈现0或1个子菜单的模式
有人知道我需要用下面的代码做什么来实现我想要的吗
<asp:ListView ID="lv" runat="server"
OnItemDataBound="LV_ItemDataBound">
<LayoutTemplate>
<nav>
<ul class="content-nav">
<asp:PlaceHolder ID="itemPlaceholder" runat="server" />
</ul>
</nav>
</LayoutTemplate>
<ItemTemplate>
<li id="liMenuItem" runat="server">
<asp:HyperLink ID="lnkMenuItem" runat="server"
CssClass="content-nav_link"></asp:HyperLink>
</li>
</ItemTemplate>
</asp:ListView>
protected void LV_ItemDataBound(object source, ListViewItemEventArgs e)
{
var item = e.Item;
if (item.ItemType == ListViewItemType.DataItem)
{
var data = (ContentNavItem)item.DataItem;
var liMenuItem = item.GetControl<HtmlGenericControl>("liMenuItem");
// Do something with the item here
}
}
void Build()
{
var currentId = MenuItems.First(x => x.Route == CurrentUrl).Id;
var currentItems = MenuItems
.Where(x => x.IsTopLevel || x.ParentId == currentId)
.OrderBy(x => x.GroupId).ThenBy(x => x.Anchor);
lv.DataSource = currentItems;
lv.DataBind();
}
受保护的void LV_ItemDataBound(对象源,ListViewItemEventArgs e)
{
var项目=e.项目;
if(item.ItemType==ListViewItemType.DataItem)
{
var data=(ContentNavItem)item.DataItem;
var liMenuItem=item.GetControl(“liMenuItem”);
//对这里的物品做点什么
}
}
void Build()
{
var currentId=MenuItems.First(x=>x.Route==CurrentUrl).Id;
var currentItems=MenuItems
.其中(x=>x.IsTopLevel | | x.ParentId==currentId)
.OrderBy(x=>x.GroupId).ThenBy(x=>x.Anchor);
lv.DataSource=当前项;
lv.DataBind();
}
使用StringBuilder
将菜单创建为字符串会容易得多。但是如果您真的想要递归控件,您可以克隆该控件并在每个菜单级别重复使用它。我在这个演示中使用了一个转发器,因为它更适合重复项目。首先我们创建一个类和一些演示数据
public class MenuItem
{
public string name { get; set; }
public List<MenuItem> menuitems { get; set; }
}
不客气。但是我会递归地构建一个字符串。但我已经发布了一个答案,表明它可以通过控制元素来实现。
protected void Page_Load(object sender, EventArgs e)
{
List<MenuItem> MenuItems = new List<MenuItem>();
for (int i = 0; i < 10; i++)
{
MenuItems.Add(new MenuItem() { name = "Name " + i });
if (i == 2 || i == 5 || i == 8)
{
MenuItems[i].menuitems = new List<MenuItem>();
MenuItems[i].menuitems.Add(new MenuItem() { name = "SubName 1" });
MenuItems[i].menuitems.Add(new MenuItem() { name = "SubName 2" });
MenuItems[i].menuitems.Add(new MenuItem() { name = "SubName 3" });
if (i == 8)
{
MenuItems[i].menuitems[0].menuitems = new List<MenuItem>();
MenuItems[i].menuitems[0].menuitems.Add(new MenuItem() { name = "SubName 1" });
MenuItems[i].menuitems[0].menuitems.Add(new MenuItem() { name = "SubName 2" });
MenuItems[i].menuitems[0].menuitems.Add(new MenuItem() { name = "SubName 3" });
}
}
}
Repeater1.DataSource = MenuItems;
Repeater1.DataBind();
}
<nav>
<asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">
<HeaderTemplate>
<ul class="content-nav">
</HeaderTemplate>
<ItemTemplate>
<li id="liMenuItem" runat="server">
<%# Eval("name") %>
<asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
</li>
</ItemTemplate>
<FooterTemplate>
</ul>
</FooterTemplate>
</asp:Repeater>
</nav>
protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
MenuItem item = e.Item.DataItem as MenuItem;
//check if the item exists and if it has subitems
if (item != null && item.menuitems != null)
{
//determine type and get the properties
Type type = sender.GetType();
PropertyInfo[] properties = type.GetProperties();
Object obj = type.InvokeMember("", BindingFlags.CreateInstance, null, sender, null);
//copy the properties
foreach (PropertyInfo propertyInfo in properties)
{
if (propertyInfo.CanWrite)
{
propertyInfo.SetValue(obj, propertyInfo.GetValue(sender, null), null);
}
}
//cast the created object back to a repeater
Repeater nestedRepeater = obj as Repeater;
//fill the child repeater with the sub menu items
nestedRepeater.DataSource = item.menuitems;
//attach the itemdatabound event
nestedRepeater.ItemDataBound += Repeater1_ItemDataBound;
//bind the data
nestedRepeater.DataBind();
//find the placeholder and add the created Repeater
PlaceHolder ph = e.Item.FindControl("PlaceHolder1") as PlaceHolder;
ph.Controls.Add(nestedRepeater);
}
}