For screenshot and source code of the content below , see : http://blogs.devhorizon.com/reza/?p=670

Description

The RepeatedControls control inherits System.Web.UI.Control and implement the marker interface INamingContainer. RepeatedControls is a container control which is designed to host other controls known as child controls.Windows SharePoint Services relies on this control to achieve a consistent look and feel to create similar HTML for various toolbars across out of the box Web parts and application pages.

Property AfterControlHTML gets or sets an HTML string to emit after the control itself is rendered whilst property BeforeControlHTML does the same thing, but before the rendition of the control.Property HeaderHtml and FooterHtml expose HTML string containing text to insert to the header/footer of the control. You may choose to use CSS classes to control header/footer appearance; for example, setting HeaderHtml property to the following string would make the toolbar match the styles of an out of the box toolbar. Matching FooterHtml element will have to close the <div> tag which was opened in the header:

HeaderHtml:

"<div class=\"ms-toolbarContainer\" width=\"100%\">"

FooterHtml:

"</div>" 

One of the most powerful properties of this class is called Template_Controls (of type ITemplate) which can be used to define the behavior of the template (child) controls added to this container control. In the CreateChildControl method of RepeatedControls control and only if Template_Controls property is set, a call into InstantiateIn(this) method is made. Once this call is made, it is the templates chance (a separate class file that implements ITemplate) to add its abstract controls into the page’s control tree. The parameter that is parsed in the InstantiateIn method is an instance of RepeatedControls control that acts as the container control.

Usage Scenario

You would typically use the RepeatedControls control to manufacture toolbars that match the styles of the out of the box toolbars. The following examples demonstrate how you can leverage RepeatedControls class to build a Web part with a toolbar and one Refresh button on it.

Code Sample in C#

public class WPT : Microsoft.SharePoint.WebPartPages.WebPart {      
      protected override void CreateChildControls()
      {
          TimeToolbar timeToolbar = new TimeToolbar();
          timeToolbar.ID = "ToolBar";
          this.Controls.Add(timeToolbar);     
          // Add a refresh button to perform a basic postback to update the current time.
          timeToolbar.AddToolbarButton(
              "RefreshTime",
              "Refresh Time",
              this.Page.ClientScript.GetPostBackEventReference(this,String.Empty),
              "Refresh the page to reload the current time",
              "/_layouts/IMAGES/refresh.gif");
          Literal currentTimeToronto = new Literal();
          currentTimeToronto.Text = string.Format("<br/>Current Date and Time:</b>{0}<br/>", DateTime.Now.ToString());
          this.Controls.Add(currentTimeToronto);
      }      
  }
/// A toolbar class that matches the styles of the out of the box toolbars.
public class TimeToolbar : RepeatedControls
{
    public TimeToolbar()
    {
        this.HeaderHtml =
          "<div class=\"ms-toolbarContainer\" width=\"100%\">";
        this.FooterHtml = "</div>";
        this.SeparatorHtml = "";
    }
    public void AddToolbarButton(string buttonId,string buttonText,string clientOnClick,string tooltipText,string buttonImageSrc)
    {
        Literal buttonMarkupLiteral = new Literal();
        buttonMarkupLiteral.Text = String.Format(
                ButtonImageHtmlFormat,
                SPHttpUtility.HtmlEncode(buttonText),
                SPHttpUtility.HtmlEncode(clientOnClick),
                SPHttpUtility.HtmlEncode(tooltipText),
                SPHttpUtility.HtmlUrlAttributeEncode(buttonImageSrc));
        buttonMarkupLiteral.ID = buttonId;
        this.Controls.Add(buttonMarkupLiteral);
    }

    // {0} = Button text
    // {1} = onclick script
    // {2} = Tooltip text
    // {3} = Button image markup
    private const string ButtonImageHtmlFormat = @"
        <DIV class=""ms-toolbarItem ms-selectorlink"">
           <A href=""#"" onclick=""{1}"" title=""{2}"">
           <IMG alt=""{2}"" src=""{3}"" border=""0"">{0}</A>
        </DIV>";
}

Code Sample in VB.NET

Public Class WPT
    Inherits Microsoft.SharePoint.WebPartPages.WebPart
    Protected Overloads Overrides Sub CreateChildControls()
        Dim timeToolbar As New TimeToolbar()
        timeToolbar.ID = "ToolBar"
        Me.Controls.Add(timeToolbar)
        ' Add a refresh button to perform a basic postback to update the current time.
        timeToolbar.AddToolbarButton("RefreshTime", "Refresh Time", Me.Page.ClientScript.GetPostBackEventReference(Me, [String].Empty), "Refresh the page to reload the current time", "/_layouts/IMAGES/refresh.gif")

        Dim currentTimeToronto As New Literal()
        currentTimeToronto.Text = String.Format("<br/>Current Date and Time:</b>{0}<br/>", DateTime.Now.ToString())
        Me.Controls.Add(currentTimeToronto)
    End Sub
End Class
''' A toolbar class that matches the styles of the out of the box toolbars.
Public Class TimeToolbar
    Inherits RepeatedControls
    Public Sub New()
        Me.HeaderHtml = "<div class=""ms-toolbarContainer"" width=""100%"">"
        Me.FooterHtml = "</div>"
        Me.SeparatorHtml = ""
    End Sub
    Public Sub AddToolbarButton(ByVal buttonId As String, ByVal buttonText As String, ByVal clientOnClick As String, ByVal tooltipText As String, ByVal buttonImageSrc As String)
        Dim buttonMarkupLiteral As New Literal()
        buttonMarkupLiteral.Text = [String].Format(ButtonImageHtmlFormat, SPHttpUtility.HtmlEncode(buttonText), SPHttpUtility.HtmlEncode(clientOnClick), SPHttpUtility.HtmlEncode(tooltipText), SPHttpUtility.HtmlUrlAttributeEncode(buttonImageSrc))
        buttonMarkupLiteral.ID = buttonId
        Me.Controls.Add(buttonMarkupLiteral)
    End Sub

    ' {0} = Button text
    ' {1} = onclick script
    ' {2} = Tooltip text
    ' {3} = Button image markup
    Private Const ButtonImageHtmlFormat As String = "" & Chr(13) & "" & Chr(10) & "        <DIV class=""ms-toolbarItem ms-selectorlink"">" & Chr(13) & "" & Chr(10) & "           <A href=""#"" onclick=""{1}"" title=""{2}"">" & Chr(13) & "" & Chr(10) & "           <IMG alt=""{2}"" src=""{3}"" border=""0"">{0}</A>" & Chr(13) & "" & Chr(10) & "        </DIV>"
End Class