MenuItemCollection.Contains(MenuItem) 方法
定义
重要
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确定指定的 MenuItem 对象是否在集合中。
public:
bool Contains(System::Web::UI::WebControls::MenuItem ^ c);public bool Contains (System.Web.UI.WebControls.MenuItem c);member this.Contains : System.Web.UI.WebControls.MenuItem -> boolPublic Function Contains (c As MenuItem) As Boolean参数
返回
如果指定的 MenuItem 对象包含在集合中，则为 true；否则为 false。
示例
下面的代码示例演示如何使用 Contains 方法确定 对象是否 MenuItem 包含在 对象中 MenuItemCollection 。
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void NavigationMenu_MenuItemClick(Object sender, MenuEventArgs e)
{
// Use the Contains method to determine whether the menu
// item selected by the user is contained in the Items
// collection of the Menu control.
if(NavigationMenu.Items.Contains(e.Item))
{
Message.Text = "You selected the root menu item.";
}
else
{
Message.Text = "You selected a submenu item.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>MenuItemCollection Contains Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>MenuItemCollection Contains Example</h3>
Select an item from the menu.
<br/><br/>
<asp:menu id="NavigationMenu"
orientation="Vertical"
target="_blank"
onmenuitemclick="NavigationMenu_MenuItemClick"
runat="server">
<items>
<asp:menuitem text="Home"
tooltip="Home">
<asp:menuitem text="Music"
tooltip="Music">
<asp:menuitem text="Classical"
tooltip="Classical"/>
<asp:menuitem text="Rock"
tooltip="Rock"/>
<asp:menuitem text="Jazz"
tooltip="Jazz"/>
</asp:menuitem>
<asp:menuitem text="Movies"
tooltip="Movies">
<asp:menuitem text="Action"
tooltip="Action"/>
<asp:menuitem text="Drama"
tooltip="Drama"/>
<asp:menuitem text="Musical"
tooltip="Musical"/>
</asp:menuitem>
</asp:menuitem>
</items>
</asp:menu>
<hr/>
<asp:label id="Message"
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub NavigationMenu_MenuItemClick(ByVal sender As Object, ByVal e As MenuEventArgs)
' Use the Contains method to determine whether the menu
' item selected by the user is contained in the Items
' collection of the Menu control.
If NavigationMenu.Items.Contains(e.Item) Then
Message.Text = "You selected the root menu item."
Else
Message.Text = "You selected a submenu item."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>MenuItemCollection Contains Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>MenuItemCollection Contains Example</h3>
Select an item from the menu.
<br/><br/>
<asp:menu id="NavigationMenu"
orientation="Vertical"
target="_blank"
onmenuitemclick="NavigationMenu_MenuItemClick"
runat="server">
<items>
<asp:menuitem text="Home"
tooltip="Home">
<asp:menuitem text="Music"
tooltip="Music">
<asp:menuitem text="Classical"
tooltip="Classical"/>
<asp:menuitem text="Rock"
tooltip="Rock"/>
<asp:menuitem text="Jazz"
tooltip="Jazz"/>
</asp:menuitem>
<asp:menuitem text="Movies"
tooltip="Movies">
<asp:menuitem text="Action"
tooltip="Action"/>
<asp:menuitem text="Drama"
tooltip="Drama"/>
<asp:menuitem text="Musical"
tooltip="Musical"/>
</asp:menuitem>
</asp:menuitem>
</items>
</asp:menu>
<hr/>
<asp:label id="Message"
runat="server"/>
</form>
</body>
</html>
注解
Contains使用 方法可确定对象是否MenuItem包含在当前 MenuItemCollection 对象中。 MenuItem及其属性与传入的值进行比较。 此方法通常用于在执行任务（例如在集合中添加或删除菜单项）之前测试对象是否存在 MenuItem 。
