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RadAsyncUpload supports the following client-side events:


To use these events, simply write a JavaScript function that can be called when the event occurs. Then assign the name of the JavaScript function as the value of the corresponding property:

<telerik:radupload id="RadUpload1" runat="server" onclientfileuploadremoving="confirmDeletes"></telerik:radupload>

You can also assign event handlers in client-side code. When using the client-side API, pass a reference to the event handler rather than its name. One advantage of using the client-side API is that you can attach multiple event handlers to one event using the standard Microsoft AJAX convention:

<script type="text/javascript">

    function confirmDeletes(sender, eventArgs) {
        if (!confirm("Are you sure you want to delete the selected row?")) eventArgs.set_cancel(true); 

    function onAddedHandler1() {
        alert("First handler called");

    function onAddedHandler2() {
        alert("Second handler called"); 

    function pageLoad() {
        var upload = $find("<%= RadUpload1.ClientID %>");

Another advantage of the client-side API is that you can detach an event handler dynamically:

<script type="text/javascript">
    function removeOnAdded2() {
        var upload = $find("<%= RadUpload1.ClientID %>");

Note that on the client-side, the names of events are slightly different than on the server side. The following table shows the correspondence between client-side and server-side names:


Server-Side Name Client-SideName Methods to add and Remove
OnClientAdded added add_added, remove_added
OnClientFileSelected fileSelected add_fileSelected, remove_fileSelected
OnClientFileUploading fileUploading add_fileUploading, remove_fileUploading
OnClientFileUploaded fileUploaded add_fileUploaded, remove_fileUploaded
OnClientFilesUploaded filesUploaded add_filesUploaded, remove_filesUploaded
OnClientProgressUpdating progressUpdating add_progressUpdating, remove_progressUpdating
OnClientValidationFailed validationFailed add_validationFailed, remove_validationFailed
OnClientFileUploadFailed fileUploadFailed add_fileUploadFailed, remove_fileUploadFailed
OnClientFileUploadRemoving fileUploadRemoving add_fileUploadRemoving, remove_fileUploadRemoving
OnClientFileUploadRemoved fileUploadRemoved add_fileUploadRemoved, remove_fileUploadRemoved

See Also

Getting Started

Client-Side Basics


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