欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  后端开发

Asp.net 菜单控件简洁版

程序员文章站 2022-04-11 11:44:06
...
本文介绍的菜单控件采用的css 和ul list来显示菜单,生成的html小,无需javascript支持,对大部分的浏览器都支持,除ie6要单独修改css也可以使其支持。
通过本文可以了解asp.net 控件的开发,及Composite设计模式的实际运用。
采用Composite设计模式设计菜单类:
MenuCompositeitem类
namespace Ruinet.Controls 
{ 
[Serializable()] 
public class MenuCompositeItem 
{ 
private List<MenuCompositeItem> _children = new List<MenuCompositeItem>(); 
private string _text; 
private string _link; 
private string _target; 
/// <summary> 
/// 菜单项 
/// </summary> 
/// <param name="text">菜单名</param> 
/// <param name="link">链接</param> 
public MenuCompositeItem(string text, string link) 
{ 
this._text = text; 
this._link = link; 
} 
/// <summary> 
/// 菜单项 
/// </summary> 
/// <param name="text">菜单名</param> 
/// <param name="link">链接</param> 
/// <param name="target">跳转目标</param> 
public MenuCompositeItem(string text, string link, string target) 
{ 
this._text = text; 
this._link = link; 
this._target = target; 
} 
/// <summary> 
/// 设置或获取菜单名 
/// </summary> 
public string Text 
{ 
get { return _text; } 
set { _text = value; } 
} 
/// <summary> 
/// 设置或获取链接 
/// </summary> 
public string Link 
{ 
get { return _link; } 
set { _link = value; } 
} 
/// <summary> 
/// 跳转目标 
/// </summary> 
public string Target 
{ 
get { return _target; } 
set { _target=value; } 
} 
/// <summary> 
/// 设置或获取子菜单 
/// </summary> 
public List<MenuCompositeItem> Children 
{ 
get { return _children; } 
set { _children = value; } 
} 
}

MenuComposite类

namespace Ruinet.Controls 
{ 
[DefaultProperty("Menu")] 
[ToolboxData("<{0}:MenuComposite runat=server></{0}:MenuComposite>")] 
public class MenuComposite : WebControl 
{ 
/// <summary> 
/// 设置获取选择的菜单 
/// </summary> 
[Bindable(true)] 
[DefaultValue("")] 
[Localizable(true)] 
public string SelectedMenuText 
{ 
get 
{ 
String s = (String)ViewState["SelectedMenuText"]; 
return ((s == null) ? String.Empty : s); 
} 
set 
{ 
ViewState["SelectedMenuText"] = value; 
} 
} 
/// <summary> 
/// 获取和设置菜单项从ViewState 
/// </summary> 
[Bindable(true)] 
[DefaultValue(null)] 
[Localizable(true)] 
public MenuCompositeItem MenuItems 
{ 
get 
{ 
return ViewState["MenuItems"] as MenuCompositeItem; 
} 
set 
{ 
ViewState["MenuItems"] = value; 
} 
} 
/// <summary> 
/// 呈现菜单结构 
/// </summary> 
/// <param name="output">HTML输出流</param> 
protected override void RenderContents(HtmlTextWriter output) 
{ 
MenuCompositeItem root = this.MenuItems; 
output.Write(@"<div class=""navmenu"">"); 
output.Write(@" <ul>"); 
for (int i = 0; i < root.Children.Count; i++) 
{ 
RecursiveRender(output, root.Children[i]); 
} 
output.Write(@" </ul>"); 
output.Write(@"</div>"); 
} 
/// <summary> 
/// 递归输出菜单项 
/// </summary> 
/// <param name="output">HTML输出流</param> 
/// <param name="item">菜单项.</param> 
/// <param name="depth">Indentation depth.</param> 
private void RecursiveRender(HtmlTextWriter output, MenuCompositeItem item) 
{ 
output.Write("<li>"); 
if (string.IsNullOrEmpty(item.Target))//为空不设置跳转目标 
{ 
output.Write(@"<a href=""" + item.Link + @""">"); 
} 
else 
{ 
output.Write(@"<a href=""" + item.Link + @""" target= """ + item.Target + @""">"); 
} 
if (item.Text == SelectedMenuText) //选中的菜单 
{ 
output.Write(@"<span class=""selected"">"); 
output.WriteLine(item.Text); 
output.WriteLine("</span>"); 
} 
else 
{ 
output.Write(item.Text); 
} 
output.Write("</a>"); 
if (item.Children.Count > 0) 
{ 
output.WriteLine(); 
output.Write("<ul>"); 
for (int i = 0; i < item.Children.Count; i++) 
{ 
RecursiveRender(output, item.Children[i]); 
} 
output.Write("</ul>"); 
} 
output.Write("</li>"); 
} 
} 
}

在页面中使用
添加对控件的引用后就可以直接在“工具箱”-》Controls组件中 看到MenuComposite组件
再就可以像其他asp.net 控件一样使用
使用:

MenuCompositeItem root = new MenuCompositeItem("root", null); 
MenuCompositeItem menu01 = new MenuCompositeItem("menu01", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu02 = new MenuCompositeItem("menu02", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu03 = new MenuCompositeItem("menu03", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu04 = new MenuCompositeItem("menu04", ResolveUrl("~/Page04.aspx")); 
MenuCompositeItem menu05 = new MenuCompositeItem("menu05", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu01_01 = new MenuCompositeItem("menu01-01", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu01_02 = new MenuCompositeItem("menu01-02", ResolveUrl("~/Page01-02.aspx")); 
MenuCompositeItem menu01_03 = new MenuCompositeItem("menu01-03", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu01_04 = new MenuCompositeItem("menu01-04", ResolveUrl("~/Default.aspx")); 
menu01.Children.Add(menu01_01); 
menu01.Children.Add(menu01_02); 
menu01.Children.Add(menu01_03); 
menu01.Children.Add(menu01_04); 

MenuCompositeItem menu02_01 = new MenuCompositeItem("menu02-01", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu02_02 = new MenuCompositeItem("menu02-02", ResolveUrl("~/Default.aspx"), "menu02-02"); 
menu02.Children.Add(menu02_01); 
menu02.Children.Add(menu02_02); 

MenuCompositeItem menu04_01 = new MenuCompositeItem("menu04-01", ResolveUrl("~/Default.aspx")); 
MenuCompositeItem menu04_02 = new MenuCompositeItem("menu04-02", ResolveUrl("~/Page04-02.aspx"), "_blank"); 
menu04.Children.Add(menu04_01); 
menu04.Children.Add(menu04_02); 
root.Children.Add(menu01); 
root.Children.Add(menu02); 
root.Children.Add(menu03); 
root.Children.Add(menu04); 
root.Children.Add(menu05);

TheMenuComposite.MenuItems = root;
此时生成的编译运行后会生成一个没有样式Ul list ,效果如下:

Asp.net 菜单控件简洁版

因此要生成可显示和隐藏的菜单项,关键在css的设置上,开始时将二级子菜单设置为隐藏visibility: hidden;
同时定义li的hover事件,li:hover时:自菜单的 visibility要改为visible; 大致原理是这样,当然还有注意菜单项的位置
一级菜单float:left;使其能水平显示。
CSS定义如下:

.navmenu * 
{ 
margin: 0; 
padding: 0; 
} 
.navmenu 
{ 
border: #000 1px solid; 
height: 25px; 
} 
.navmenu li 
{ 
/*水平菜单*/ 
float: left; 
list-style: none; 
position: relative; 
} 
.navmenu a 
{ 
display: block; 
font-size: 12px; 
height: 24px; 
width: 100px; 
line-height: 24px; 
background-color: #CDEB8B; 
color: #0000ff; 
text-decoration: none; 
text-align: center; 
border-left: #36393D 1px inset; 
border-right: #36393D 1px inset; 
border-bottom: #36393D 1px inset; 
} 
/*单独设置一级菜单样式*/ 
.navmenu > ul > li > a 
{ 
font-size: 11px; 
font-weight: bold; 
} 
.navmenu a:hover 
{ 
background: #369; 
color: #fff; 
} 
/*新增的二级菜单部分*/ 
.navmenu ul ul 
{ 
visibility: hidden; /*开始时是隐藏的*/ 
position: absolute; 
left: 0px; 
top: 24px; 
} 
.navmenu ul li:hover ul, .navmenu ul a:hover ul 
{ 
visibility: visible; 
} 
.navmenu ul ul li 
{ 
clear: both; /*垂直显示*/ 
text-align: left; 
} 
/*选中菜单项*/ 
.navmenu .selected 
{ 
padding-left:15px; 
background-position-x:0px; 
background-image: url(./res/selected.gif); 
background-repeat: no-repeat; 
text-decoration:underline; 
}

定义CSS后的效果如下:

Asp.net 菜单控件简洁版

到此菜单控件已完成。已测试过可以在IE7,IE8,Chrome,Firefox中正常显示,在IE6显示可能会有问题,可以参考纯CSS多级菜单 进行修改,
更多Asp.net 菜单控件简洁版相关文章请关注PHP中文网!