title: Telerik RadAsyncUpload UploadedFile Count is giving 0 when invalid file is uploaded
body: <p>Hi i'm using <code>Telerik</code> <code>RadAsyncUpload</code>, I have kept a filter that <code>.csv</code> files are only allowed. </p>
  
  <p><strong>In Designer:</strong></p>
  
  <pre><code>&lt;telerik:RadAsyncUpload ID="RadAsyncUpload1" runat="server" 
      EnableInlineProgress="true" UploadedFilesRendering="BelowFileInput" 
      HideFileInput="true" ClientIDMode="AutoID" MultipleFileSelection="Disabled"
      Localization-Select="Choose File" Width="100%"
      AllowedFileExtensions=".csv,.CSV" AllowedMimeTypes="application/csv"
      Filter="Others(*.csv;*.CSV)|*.csv;*.CSV" 
      MaxFileInputsCount="1"&gt;
      &lt;FileFilters&gt;
          &lt;telerik:FileFilter Description="Others(*.csv;*.CSV)|*.csv;*.CSV"
              Extensions=".csv,.CSV" /&gt;
      &lt;/FileFilters&gt;
      &lt;Localization Select="Choose File" /&gt;
  &lt;/telerik:RadAsyncUpload&gt;
  </code></pre>
  
  <p><strong>In Code behind:</strong></p>
  
  <pre><code>var csv = new[] { ".csv" };
  rauploadCSVFile.AllowedMimeTypes = csv;
  rauploadCSVFile.AllowedFileExtensions = csv;
  </code></pre>
  
  <p>color indication when <code>.csv</code> file uploaded is green, non <code>.csv</code> file is red -- Okay i have no issues here.</p>
  
  <p>but when non <code>.csv</code> file is uploaded, <code>RadAsyncUpload1.UploadedFiles.Count</code> returns 0, here the truth is that 1 invalid file is uploaded (non .csv file), that means count must be 1.</p>
  
  <p>here i'm in a scenario:</p>
  
  <p><strong>scenario 1:</strong> when no file is given <code>RadAsyncUpload1.UploadedFiles.Count</code> returns 0, Now user display message: <code>File is mandatory</code>.</p>
  
  <p><strong>scenario 2:</strong> when non .csv file is given <strong>still</strong> <code>RadAsyncUpload1.UploadedFiles.Count</code> returns 0, Now user display message: <code>Only CSV files are allowed.</code></p>
  
  <p><strong>Question 1:</strong> How can I achieve this?</p>
  
  <p><strong>Question 2:</strong> How to make RadAsyncUpload1 to show File Upload Dialog window's filter to display only 
  <strong>Other (*.csv)</strong> instead of All Files(*.*),..etc </p>
  
  <p>so that only .csv are shown in file system while choosing.</p>