ASP.NET 4 : Highlight menu item for current page

问题:

I use this code in ASP.NET 4 for creating menu and add StaticSelectedStyle & DynamicSelectedStyle for highlight menu item for current page :

  <asp:Menu ID="Menu1" runat="server" BackColor="#E3EAEB" 
      DynamicHorizontalOffset="2" Font-Names="Verdana" Font-Size="0.8em" 
      ForeColor="#666666" Orientation="Horizontal" RenderingMode="List" 
      StaticSubMenuIndent="10px">
      <DynamicSelectedStyle backcolor="LightBlue"
  borderstyle="Solid"
  bordercolor="Black"
  borderwidth="1"/>
      <StaticSelectedStyle backcolor="LightBlue"
  borderstyle="Solid"
  bordercolor="Black"
  borderwidth="1"/>

  </asp:Menu>

But for dynamic pages highlight current item is not working.
What is wrong?
Is there better way for highlight menu item for current page?

回答1:

You need to set the Selected MenuItem Manually

NavigationMenu.Items(i).Selected = True

I've created a function to make highlighting easier.

SelectMenuByValue("Value2", NavigationMenu)

It takes the Value of the MenuItem and the Menu control instance as Parameters.

<asp:Menu ID="NavigationMenu" runat="server">
    <Items>
        <asp:MenuItem Text="Parent1" Value="ParentValue">
            <asp:MenuItem Text="SubMenu1" Value="Value1" NavigateUrl="~/Page1.aspx" />
            <asp:MenuItem Text="SubMenu2" Value="Value2" NavigateUrl="~/Page2.aspx" />
            <asp:MenuItem Text="SubMenu3" Value="Value3" NavigateUrl="~/Page3.aspx" />
        </asp:MenuItem>
    </Items>
</asp:Menu>

code-behind:

Public Sub SelectMenuByValue(ByVal sValue As String, ByVal NavigationMenu As Menu)
    Dim iMenuCount As Integer = NavigationMenu.Items.Count - 1
    For i As Integer = 0 To iMenuCount
        Dim menuItem As MenuItem = NavigationMenu.Items(i)
        If menuItem.Value = sValue Then
            If menuItem.Enabled AndAlso menuItem.Selectable Then menuItem.Selected = True
            Exit For
        End If
        If CheckSelectSubMenu(menuItem, sValue) Then Exit For
    Next
End Sub

Private Function CheckSelectSubMenu(ByVal menuItem As MenuItem, ByVal sValue As String) As Boolean
    CheckSelectSubMenu = False
    Dim iMenuCount As Integer = menuItem.ChildItems.Count - 1
    For i As Integer = 0 To iMenuCount
        Dim subMenuItem As MenuItem = menuItem.ChildItems(i)
        If subMenuItem.Value = sValue Then
            CheckSelectSubMenu = True
            If subMenuItem.Enabled AndAlso subMenuItem.Selectable Then subMenuItem.Selected = True
            Exit For
        End If
        If CheckSelectSubMenu(subMenuItem, sValue) Then
            CheckSelectSubMenu = True
            Exit For
        End If
    Next
End Function

Limitations:

• There is no way to select 2 or more MenuItem at once, so the parentMenu cannot be higlighted also if one of its submenu is selected. well you can do this in jQuery though.

• If you have 2 or more menuItems that has the same Value, the first one will be selected.