The base control

The control that will be used for this article will the same one that we used in Posting Back in Custom Controls (Single Highlight). However, first we will make some changes to it -

When you inherit from System.Web.UI.WebControls.WebControl you automatically get a bunch of properties that by default already show up in VS.NET (including BackColor, BorderStyle, Font, CssClass etc.) which you can chose to implement of not (you could also inherit from System.Web.UI.Control and not get any of those properties) . In our new highlighting class (VSHighlight) we will be using some of these properties.

We are also going to need some additional properties that aren't initially provided by the base class (eg. the Text of the control and the alternating background color).

Below is the new class -

Public Class VSHighlight Inherits System.Web.UI.WebControls.WebControl Implements IPostBackEventHandler Private pvText As String Private tColor As System.Drawing.Color = System.Drawing.Color.Black Private bgColoron As System.Drawing.Color = System.Drawing.Color.LimeGreen Public Property TextColor() As System.Drawing.Color Get Return tColor End Get Set(ByVal Value As System.Drawing.Color) tColor = Value End Set End Property Public Property BackColor_On() As System.Drawing.Color Get Return bgColoron End Get Set(ByVal Value As System.Drawing.Color) bgColoron = Value End Set End Property Public Property Text() As String Get Return pvText End Get Set(ByVal Value As String) pvText = Value End Set End Property Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter) output.AddAttribute("border", "1") output.AddAttribute("onClick", Page.GetPostBackEventReference(Me)) If Viewstate(ID & "click") = 1 Then output.AddAttribute("bgcolor", BackColor_On.ToKnownColor.ToString()) Else output.AddAttribute("bgcolor", MyBase.BackColor.ToKnownColor.ToString()) End If output.AddStyleAttribute("cursor", "hand") output.AddStyleAttribute("border-width", MyBase.BorderWidth.Value.ToString()) output.AddStyleAttribute("border-color", MyBase.BorderColor.ToKnownColor.ToString()) output.AddStyleAttribute("height", "5") output.AddStyleAttribute("border-style", MyBase.BorderStyle.ToString()) output.RenderBeginTag("table") output.RenderBeginTag("tr") output.RenderBeginTag("td") output.AddAttribute("face", "Arial") output.AddAttribute("size", "4") output.RenderBeginTag("font") output.RenderBeginTag("b") Page.Response.Write(Text) output.RenderEndTag() output.RenderEndTag() output.RenderEndTag() output.RenderEndTag() output.RenderEndTag() End Sub Public Sub RaisePostBackEvent(ByVal eventargs As String) _ Implements IPostBackEventHandler.RaisePostBackEvent If ViewState(ID & "click") = 1 Then ViewState(ID & "click") = 0 Else ViewState(ID & "click") = 1 End If End Sub End Class