Programming ASP .NET

Panel Control

The Panel control is used as a container for other controls. It serves several functions:

• To control the visibility of the controls it contains

• To control the appearance of the controls it contains

• To make it easier to generate controls programmatically

The Panel control is derived from WebControl and adds the properties shown in Table 5-15.

Table 5-15. Properties of the Panel control not inherited from WebControl

Name	Type	Get	Set	Values	Description
BackImageURL	String	x	x		The URL of an image to display behind the table. If the image is smaller than the table, it is tiled.
HorizontalAlign	HorizontalAlign	x	x	Center, Justify, Left, NotSet, Right	Specifies the horizontal alignment of the contents of all the cells in the row. Default is NotSet. Note there is no VerticalAlign property.
Wrap	Boolean	x	x	true, false	If true (the default), the contents of the cell wraps. If false, contents do not wrap.

Example 5-31 demonstrates how to control the appearance and visibility of child controls and add controls programmatically using C#. Example 5-32 shows the script block of the same program in VB.NET. The HTML section of the code is the same for both the VB.NET and C# versions; consequently, the HTML is shown only in the C# version.

Example 5-31. Panel control using C#, csAspPanel.aspx

<%@ Page Language="C#" %> <script runat="server"> void Page_Load(Object sender, EventArgs e) { // Show/Hide Panel Contents if (chkHide.Checked) { pnl.Visible=false; ...