BootstrapCallbackPanel.Callback Event

Fires when a round trip to the server has been initiated by a call to the client BootstrapClientCallbackPanel.PerformCallback method.

Namespace: DevExpress.Web.Bootstrap

Assembly: DevExpress.Web.Bootstrap.v24.1.dll

NuGet Package: DevExpress.Web.Bootstrap

Declaration

C#

public event CallbackEventHandlerBase Callback

VB.NET

Public Event Callback As CallbackEventHandlerBase

Event Data

The Callback event's data class is CallbackEventArgsBase. The following properties provide information specific to this event:

Property	Description
Parameter	Gets a string that contains specific information (if any) passed from the client side.

Example

This example demonstrates the basic functionality of the Callback Panel.

• Initialize a new instance of the BootstrapCallbackPanel class.
• Add required controls to the ContentCollection array.
• Use the client BootstrapClientCallbackPanel.PerformCallback method to initiate a callback. Handle the BootstrapCallbackPanel.Callback event to process a callback on the server side.

The image below shows the result:

C#

protected void CallbackPanel_Callback(object sender, DevExpress.Web.CallbackEventArgsBase e) {
    if(!string.IsNullOrEmpty(e.Parameter))
        passedInfo.InnerText = "Passed information: \"" + e.Parameter + "\"";
}

JS

function onUpdateClick(s, e) {
    callbackPanel.PerformCallback("caused on the button click");
}

ASPX

<dx:BootstrapCallbackPanel runat="server" ClientInstanceName="callbackPanel" OnCallback="CallbackPanel_Callback">
    <ContentCollection>
        <dx:ContentControl>
            <div class="card">
                <div class="card-body">
                    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse sem lorem, rutrum at tincidunt aliquam, vulputate sit amet tellus. In hac habitasse platea dictumst. Morbi in dui a massa volutpat tristique. Aenean ultrices, elit ac commodo vestibulum, nisl neque pharetra est, id egestas neque leo dignissim augue. Vestibulum sodales metus at est maximus dictum. Quisque cursus felis id nisi auctor, volutpat imperdiet neque feugiat. Sed aliquet elit sem, ut vulputate lectus ultricies sit amet.</p>
                    <p><span class="badge badge-info"><%= IsCallback ? "The content was updated at " + DateTime.Now.ToLongTimeString() : "" %></span></p>
                    <small runat="server" id="passedInfo"></small>
                </div>
            </div>
        </dx:ContentControl>
    </ContentCollection>
</dx:BootstrapCallbackPanel>
<dx:BootstrapButton Text="Update" AutoPostBack="false" UseSubmitBehavior="false" runat="server">
    <ClientSideEvents Click="onUpdateClick" />
</dx:BootstrapButton>