Introduction

Continuous from Part - 2, in previous article we have seen that how User Controls are registering in Web.config file to use entirely in website. Now in this article we will discuss how to expose the properties from a User Control. We have noticed that the RandomImage User control always displays an image from the Images folder. It would be nice if we could specify the name of the folder that contains the images so that we could use different folder paths in different applications. We can do this by exposing a property from the RandomImage User control. The modified RandomImage control is now named as PropertyRandomImage, exposes a property named ImageFolderPath.

PropertyRandomImage.ascx File Code

<%@ Control Language="VB" ClassName="PropertyRandomImage" %>
<%@ Import Namespace="System.IO" %>
<script runat="server">

Private _imageFolderPath As String = "~/images1"

Public Property ImageFolderPath() As String
 Get
 Return _imageFolderPath
End Get
 Set(ByVal Value As String)
_imageFolderPath = value
End Set
 End Property

Private Sub Page_Load()
Dim imageToDisplay As String = GetRandomImage()
imgRandom.ImageUrl = Path.Combine(_imageFolderPath, imageToDisplay)
lblRandom.Text = imageToDisplay
End Sub

Private Function GetRandomImage() As String
 Dim rnd As New Random()
Dim images() As String = Directory.GetFiles(MapPath("~/images1"), "*.JPG")
Dim imageToDisplay As String = images(rnd.Next(images.Length))
Return Path.GetFileName(imageToDisplay)
End Function
</script>

<asp:Image
 id="imgRandom"
 Width="300px"
 Runat="server" />
<br />
<asp:Label
 id="lblRandom"
 Runat="server" />

Default.aspx File Code

<%@ Page Language="VB" CodeFile="Default.aspx.vb" Inherits="_Default"%>

<%@ Register TagPrefix="user" TagName="PropertyRandomImage" Src="~/PropertyRandomImage.ascx" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
 <title></title>
</head>
<body>
 <form id="form1" runat="server">
 <div>

<user:PropertyRandomImage
 ID="PropertyRandomImage1"
 ImageFolderPath="~/images1"
 Runat="server" />
</div>
 </form>
</body>
</html>

Default2.aspx File Code

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default2.aspx.vb" Inherits="Default2" %>

<%@ Register TagPrefix="user" TagName="PropertyRandomImage" Src="~/PropertyRandomImage.ascx" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
PropertyRandomImage1.ImageFolderPath = "~/images2"
 End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
 <title></title>
</head>
<body>
 <form id="form1" runat="server">
 <div>

<user:PropertyRandomImage
 ID="PropertyRandomImage1"
 Runat="server" />

</div>
 </form>
</body>
</html>

Note: Continue in next part.

HAVE A GREAT CODING!