title: C# and Excel advanced filter
body: <p>I'm trying to filter data from one workbook to another obne, but I get an unpsecified exception.         </p>
  
  <p>I can't find many examples for adavnced filtering in excel using c# and I don't know Where's exactly my error. </p>
  
  <p>Here's my code:</p>
  
  <pre><code>public void excel()
      {
          Excel.Application xlApp;
          Excel.Workbook xlWorkBookImport;
          Excel.Workbook xlWorkBookOriginal;
          Excel.Worksheet xlWorkSheetImport;
          Excel.Worksheet xlWorkSheetOriginal;
  
          xlApp = new Excel.ApplicationClass();
          xlWorkBookImport = xlApp.Workbooks.Open("c:/open.xls");
          xlWorkBookOriginal = xlApp.Workbooks.Open("c:/open1.xls");
          xlWorkBookOriginal.Activate();
          xlWorkSheetOriginal = (Excel.Worksheet)xlWorkBookOriginal.Worksheets.get_Item(1);
          xlWorkSheetOriginal.get_Range("1:7").Delete();
          xlWorkBookImport.Activate();
          xlWorkSheetImport = (Excel.Worksheet)xlWorkBookImport.Worksheets.get_Item(1);
          xlWorkSheetOriginal.Cells.AdvancedFilter(Excel.XlFilterAction.xlFilterCopy, Type.Missing, CopyToRange: "a1:a6", Unique: true);
  
          xlApp.Visible = true;
      }
  </code></pre>
  
  <p>Anyone can help me with a solution? </p>