Using the Menu Control in .NET

Printer GS1 - 12 in .NET Using the Menu Control

You could spend years designing a Menu complete with padded borders, shaded backgrounds, custom icons, fancy separators, and dynamic fly-out effects ASPNET provides a starting point for your creativity by way of the Auto Format dialog box To reach Auto Format, right-click the Menu control, and then (from the context menu) click Auto Format If you choose the Classic format, the designer inserts a series of style tags just before the closing </asp:menu> tag The following code shows some sample markup:

<staticmenuitemstyle horizontalpadding= 5px verticalpadding= 2px /> <dynamichoverstyle backcolor= #284E98 forecolor= White /> <dynamicmenustyle backcolor= #B5C7DE /> <staticselectedstyle backcolor= #507CD1 /> <dynamicselectedstyle backcolor= #507CD1 /> <dynamicmenuitemstyle horizontalpadding= 5px verticalpadding= 2px /> <statichoverstyle backcolor= #284E98 forecolor= White />

It s hard to design beautiful dynamic Menu items if the designer is showing only the static content You can make dynamic items visible on the design surface with the help of a Smart Tag item Here s how:

Dynamic, as shown in Figure 3-13 The view changes to show a sample of the dynamic content You can switch back to the static view by selecting Static

This Views feature has its limitations because there s no Hover or Selected option to let you view static or dynamic menu items in those states For that, there s good old trial-and-error design Although you can change attributes by editing the markup, it s faster to use properties pages Let s change the hover style of the dynamic menu items:

2 Locate the DynamicHoverStyle property and expand its node 3 Set the properties and values for the style using the data in Table 3-3

Table 3-3

In addition to building and configuring a Menu control in markup (that is, declaratively), you can assemble everything in code Even if you don t want

to create every Menu this way, it helps to know how to add or change elements of the control on the fly A better way to create a Menu is to bind it to the Websitemap file To learn how to do that, skip ahead to the section Creating a Menu from a sitemap, later in this chapter

A Menu is mainly items and subitems that are hooked together in a hierarchy No matter where they appear, all Menu items belong to the same class, Menu Item The first order of business is to create a function that assembles Menu items for us according to specifications The BuildItem() function that follows takes the text that appears on the item as a string and an optional URL The URL isn t required for top-level static items because they might serve only as a gateway to the subitems below them After assigning the parameters to the appropriate properties, the function returns a MenuItem object that we can insert into the Menu s hierarchy Here s the BuildItem routine in VB:

Private Function BuildItem _ (ByVal strText As String, _ Optional ByVal strURL As String = ) As MenuItem Dim menuItem As New MenuItem menuItemText = strText menuItemValue = strText menuItemNavigateUrl = strURL Return menuItem End Function

To create a Menu from scratch, you need an instance of the ASPNET Menu class, declared in the following code in the variable mnu:

Dim mnu As New Menu mnuBackColor = DrawingColorFromArgb(181, 199, 222) mnuDisappearAfter = 1000 mnuDynamicHorizontalOffset = 2 mnuFontNames = New String() { Verdana } mnuFontSize = FontUnitLarge mnuForeColor = DrawingColorFromArgb(40, 78, 152) mnuID = Menu1 mnuOrientation = OrientationHorizontal mnuStaticSubMenuIndent = UnitPixel(10) PlaceHolder1ControlsAdd(mnu)

The Menu has certain characteristics that it shares with Menu items, such as font sizes, text colors, and backgrounds Some properties are unique, such