title: How to check whether a excel file is write protected or not in C#?
body: <p>I'm developing a sample application in which I have to open an excel file and check whether the file is write protected or not. The code is </p>
  
  <pre><code>using System.Windows.Forms;
  using Microsoft.Office.Core;
  
  private void button1_Click(object sender, EventArgs e)
  {
      string fileNameAndPath = @"D:\Sample\Sample1.xls"; 
      // the above excel file is a write protected.
  
      Microsoft.Office.Interop.Excel.Application a = 
                new  Microsoft.Office.Interop.Excel.Application();
      if (System.IO.File.Exists(fileNameAndPath))
      {
          Microsoft.Office.Interop.Excel.ApplicationClass app = 
                new Microsoft.Office.Interop.Excel.ApplicationClass();
  
          // create the workbook object by opening  the excel file.
          app.Workbooks.Open(fileNameAndPath,0,false,5,"","",true,
                             Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,
                             "\t",false, true, 0,false,true,0);
  
          Microsoft.Office.Interop.Excel._Workbook w = 
                app.Workbooks.Application.ActiveWorkbook;
  
          if (w.ReadOnly)
                MessageBox.Show("HI");
          // the above condition is true.
      }
  
  }
  </code></pre>
  
  <p>I would like know whether the file is write protected or not.</p>