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File Upload in Ajaxified Grid

File upload is not supported using AJAX calls. This is a limitation of the XmlHttpRequest component, used in all AJAX frameworks for asynchronous calls to the application. In order to upload a file you should perform a full page postback.

Fortunately, there is a workaround available which can allow you to upload files while still using AJAX to improve the performance of RadGrid. If you have button (or other control) which normally does postbacks, you can attach an event handler to the OnRequestStart client-side event of the RadAjaxManager or RadAjaxPanel that disables the AJAX functionality when that particular button is clicked.

The following example illustrates this approach:

<telerik:RadCodeBlock runat="server" ID="RadCodeBlock2">
  <script type="text/javascript">
    //on insert and update buttons click temporarily disables ajax to perform upload actions
    function conditionalPostback(sender, e) {
      var theRegexp = new RegExp("\.UpdateButton$|\.PerformInsertButton$", "ig");
      if (e.get_eventTarget().match(theRegexp)) {
<telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server" ClientEvents-OnRequestStart="conditionalPostback">
  <telerik:RadProgressManager ID="RadProgressManager1" runat="server" />
  <telerik:RadProgressArea RenderMode="Lightweight" ID="RadProgressArea1" runat="server" />
  <telerik:RadGrid RenderMode="Lightweight" runat="server" ID="RadGrid1" AllowPaging="True" AllowSorting="True"
    AutoGenerateColumns="False" Width="97%" DataSourceID="SqlDataSource1" AllowAutomaticInserts="true"
    AllowAutomaticUpdates="true" AllowAutomaticDeletes="true" ShowStatusBar="True"
    GridLines="None" OnItemDataBound="RadGrid1_ItemDataBound" OnItemCreated="RadGrid1_ItemCreated"
    <MasterTableView Width="100%" CommandItemDisplay="Top" DataKeyNames="ID" DataSourceID="SqlDataSource1">
        <telerik:GridEditCommandColumn ButtonType="ImageButton">
        <telerik:GridBinaryImageColumn DataField="Data" HeaderText="Image" UniqueName="Upload">
        <EditColumn ButtonType="ImageButton" />
    <PagerStyle Mode="NumericPages" AlwaysVisible="true" />

An online demo demonstrating the approach in reality can be viewed here

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