<%@ Register Assembly="AsyncControls" Namespace="DelvingWare.AsyncControls" TagPrefix="dw" %>

<dw:AsyncLabel runat="server" ID="lblMain" 
RenderMode="Paragraph" 
CssClass="placeHolderLabel">Add a dynamically created AsyncControl</dw:AsyncLabel>

<dw:AsyncPlaceHolder runat="server" ID="phMain" />

<p>
<dw:AsyncButton runat="server" ID="btAdd" 
OnClick="btAdd_Click" 
CausesValidation="true" 
Text="Add AsyncControl"
CssClass="greyButton" />

<dw:AsyncButton runat="server" ID="btRemove" 
OnClick="btRemove_Click"
CausesValidation="true" 
Text="Remove AsyncControl" 
CssClass="greyButton"/>
</p>

<p>
Dynamically Create: <dw:AsyncDropDownList runat="server" ID="drpMain" 
EnableValidation="enabled" 
InitialValue="none"
ErrorMessageCssClass="errorMsg"
ErrorMessage="Please select a valid control.">
    <dw:AsyncListItem Value="none" />
    <dw:AsyncListItem Value="window">AsyncWindow</dw:AsyncListItem>
    <dw:AsyncListItem Value="link">AsyncLinkButton</dw:AsyncListItem>
    <dw:AsyncListItem Value="button">AsyncButton</dw:AsyncListItem>
</dw:AsyncDropDownList>
</p>

using System;
using DelvingWare.AsyncControls;
...
protected void btAdd_Click( object sender, AsyncEventArgs ae )
{
    // ensure validation passed
    if ( !AsyncPage.IsValid )
        return;

    int cCount = phMain.Controls.Count+1;

    // check the control collection count
    if ( phMain.Controls.Count == 5 )
    {
        // display the restriction to the user
        AsyncPage.Alert("This demo only allows 5 controls to be created.");
        return;
    } 


    switch ( drpMain.SelectedValue )
    {
        case "window":
            // get the number of AsyncWindows in the place holder
            int wndCount = phMain.Controls.FindControlsByType(typeof(AsyncWindow)).Length;
            if ( wndCount == 2 )
            {
                AsyncPage.Alert("This demo only allows 2 AsyncWindows to be created.");
                return;
            }
                            
            // create the AsyncWindow and set the values
            AsyncWindow wnd = new AsyncWindow(); // <-- generate unique ID
            wnd.ID = "wnd"+ ((byte)DateTime.Now.Ticks);
            wnd.Title = "New AsyncWindow "+(wndCount+1);
            wnd.DefaultStyle = false;
            wnd.CssClass = "asyncWin2";
            wnd.TitleBarCssClass = "titleBar2";
            wnd.TitleCssClass = "titleBarText2";
                wnd.TitleBarButtonHeight = 28;
                wnd.TitleBarButtonWidth = 42;
            wnd.ShadowCssClass = "awShadow";
            wnd.Height = 300;
            wnd.Width = 200;
            wnd.Top = 400;
            wnd.Left = 150*cCount;
            wnd.Closed += new AsyncEventHandler(wnd_Closed);
            wnd.CloseIconUrl = "../images/vistaClose.gif";
            wnd.AllowCollapsing = false;

            // add the control to the AsyncPlaceHolder
            phMain.Controls.Add(wnd);
            break;

        case "button":
            // create the AsyncButton and set the values
            AsyncButton bt = new AsyncButton();
            bt.ID = "bt"+ cCount;
            bt.Text = "New AsyncButton "+ cCount;
            bt.Click += new AsyncEventHandler(bt_Click);

            // add the control to the AsyncPlaceHolder
            phMain.Controls.Add(bt);
            break;

        case "link":
            // create the AsyncLinkButton and set the values
            AsyncLinkButton lnk = new AsyncLinkButton();
            lnk.ID = "lnk"+ cCount;
            lnk.Text = "New AsyncLinkButton "+ cCount;
            lnk.Click += new AsyncEventHandler(lnk_Click);

            // add the control to the AsyncPlaceHolder
            phMain.Controls.Add(lnk);
            break;
    } // end SWITCH

    // update the client side AsyncPlaceHolder
    phMain.UpdatePlaceHolder();
}

void wnd_Closed( object sender, AsyncEventArgs ae )
{
    // remove the control from the AsyncPlaceHolder
    phMain.Controls.Remove(sender as IAsyncWidget);

    // check the tag value
    if ( btRemove.Tag == "remove" )
    {
        // update the client side AsyncPlaceHolder
        phMain.UpdatePlaceHolder();

        btRemove.Enabled = true; // <-- enable the remove button

        // display the notification to the user
        AsyncPage.MessageBox("Removed "+ (sender as AsyncWindow).Title, 3000);

        // clear tag
        btRemove.Tag = string.Empty;
        return;
    } 

    // display the notification to the user
    AsyncPage.MessageBox("Closed "+ (sender as AsyncWindow).Title, 3000);
}

void lnk_Click( object sender, AsyncEventArgs ae )
{
    // check the tag value
    if ( btRemove.Tag == "remove" )
    {
        // remove the control
        phMain.Controls.Remove(sender as IAsyncWidget);
        phMain.UpdatePlaceHolder();
        btRemove.Enabled = true;

        // clear tag
        btRemove.Tag = string.Empty;
        return;
    } 

    // update the client side label
    lblMain.Text = "Clicked "+ (sender as AsyncLinkButton).Text;
}

void bt_Click( object sender, AsyncEventArgs ae )
{
    if ( btRemove.Tag == "remove" )
    {
        // remove the control
        phMain.Controls.Remove(sender as IAsyncWidget);
        phMain.UpdatePlaceHolder();
        btRemove.Enabled = true;

        // clear tag
        btRemove.Tag = string.Empty;
        return;
    } 

    // update the client side label
    lblMain.Text = "Clicked "+ (sender as AsyncButton).Text;
}

protected void btRemove_Click( object sender, AsyncEventArgs ae )
{
    // set the tag value
    btRemove.Tag = "remove";

    // disable the button
    btRemove.Enabled = false;

    // display some instructions (for 5 seconds)
    AsyncPage.MessageBox("Click on a AsyncControl you want to remove. <p/>"+
        "Remove an AsyncWindow by closing it (click the title bar). <br/>"+
        "Remove an AsyncLinkButton or AsyncButton by clicking it.", 5000);
}

Imports System
Imports DelvingWare.AsyncControls
...

Protected Sub btAdd_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' ensure validation passed
    If Not AsyncPage.IsValid Then
        Return
    End If
    Dim cCount As Integer = (phMain.Controls.Count + 1)
    ' check the control collection count
    If (phMain.Controls.Count = 5) Then
        ' display the restriction to the user
        AsyncPage.Alert("This demo only allows 5 controls to be created.")
        Return
    End If
    Select Case (drpMain.SelectedValue)
        Case "window"
            ' get the number of AsyncWindows in the place holder
            Dim wndCount As Integer = phMain.Controls.FindControlsByType(GetType(AsyncWindow)).Length
            If (wndCount = 2) Then
                AsyncPage.Alert("This demo only allows 2 AsyncWindows to be created.")
                Return
            End If
            ' create the AsyncWindow and set the values
            Dim wnd As AsyncWindow = New AsyncWindow
            ' <-- generate unique ID
            wnd.ID = ("wnd" + CType(DateTime.Now.Ticks,Byte))
            wnd.Title = ("New AsyncWindow "  _
                        + (wndCount + 1))
            wnd.DefaultStyle = false
            wnd.CssClass = "asyncWin2"
            wnd.TitleBarCssClass = "titleBar2"
            wnd.TitleCssClass = "titleBarText2"
            wnd.TitleBarButtonHeight = 28
            wnd.TitleBarButtonWidth = 42
            wnd.ShadowCssClass = "awShadow"
            wnd.Height = 300
            wnd.Width = 200
            wnd.Top = 400
            wnd.Left = (150 * cCount)
            AddHandler wnd.Closed, AddressOf Me.wnd_Closed
            wnd.CloseIconUrl = "../images/vistaClose.gif"
            wnd.AllowCollapsing = false
            ' add the control to the AsyncPlaceHolder
            phMain.Controls.Add(wnd)
        Case "button"
            ' create the AsyncButton and set the values
            Dim bt As AsyncButton = New AsyncButton
            bt.ID = ("bt" + cCount)
            bt.Text = ("New AsyncButton " + cCount)
            AddHandler bt.Click, AddressOf Me.bt_Click
            ' add the control to the AsyncPlaceHolder
            phMain.Controls.Add(bt)
        Case "link"
            ' create the AsyncLinkButton and set the values
            Dim lnk As AsyncLinkButton = New AsyncLinkButton
            lnk.ID = ("lnk" + cCount)
            lnk.Text = ("New AsyncLinkButton " + cCount)
            AddHandler lnk.Click, AddressOf Me.lnk_Click
            ' add the control to the AsyncPlaceHolder
            phMain.Controls.Add(lnk)
    End Select
    ' end SWITCH
    ' update the client side AsyncPlaceHolder
    phMain.UpdatePlaceHolder
End Sub

Private Sub wnd_Closed(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' remove the control from the AsyncPlaceHolder
    phMain.Controls.Remove(CType(sender,IAsyncWidget))
    ' check the tag value
    If (btRemove.Tag = "remove") Then
        ' update the client side AsyncPlaceHolder
        phMain.UpdatePlaceHolder
        btRemove.Enabled = true
        ' <-- enable the remove button
        ' display the notification to the user
        AsyncPage.MessageBox(("Removed " + CType(sender,AsyncWindow).Title), 3000)
        ' clear tag
        btRemove.Tag = string.Empty
        Return
    End If
    ' display the notification to the user
    AsyncPage.MessageBox(("Closed " + CType(sender,AsyncWindow).Title), 3000)
End Sub

Private Sub lnk_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' check the tag value
    If (btRemove.Tag = "remove") Then
        ' remove the control
        phMain.Controls.Remove(CType(sender,IAsyncWidget))
        phMain.UpdatePlaceHolder
        btRemove.Enabled = true
        ' clear tag
        btRemove.Tag = string.Empty
        Return
    End If
    ' update the client side label
    lblMain.Text = ("Clicked " + CType(sender,AsyncLinkButton).Text)
End Sub

Private Sub bt_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    If (btRemove.Tag = "remove") Then
        ' remove the control
        phMain.Controls.Remove(CType(sender,IAsyncWidget))
        phMain.UpdatePlaceHolder
        btRemove.Enabled = true
        ' clear tag
        btRemove.Tag = string.Empty
        Return
    End If
    ' update the client side label
    lblMain.Text = ("Clicked " + CType(sender,AsyncButton).Text)
End Sub

Protected Sub btRemove_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' set the tag value
    btRemove.Tag = "remove"
    ' disable the button
    btRemove.Enabled = false
    ' display some instructions (for 5 seconds)
    AsyncPage.MessageBox(("Click on a AsyncControl you want to remove. <p/>" + ("Remove an AsyncWindow by closing it (click the title bar). <br/>" + "Remove an AsyncLinkButton or AsyncButton by clicking it.")), 5000)
End Sub

.placeHolderLabel 

{
    color: #777;
    font-family: Verdana, Arial, Serif;
}
.msgBox 

{
    font-size: 10pt;
    padding: .5em;
    background-color: White;
    border: 1px solid black;
    position: absolute;
    left: 850px;
    filter:alpha(opacity=85);
    -moz-opacity:.75;opacity:.85;
}