对Office文档进行授权

             Microsoft.Office.Interop.Word.ApplicationClass app = new Microsoft.Office.Interop.Word.ApplicationClass();
             object filePath = @"D:\auth.docx";
             object missing = System.Reflection.Missing.Value;
             Microsoft.Office.Interop.Word.Document doc = app.Documents.Open(ref filePath);
             try
             {
                 doc.Activate();

                 Microsoft.Office.Core.Permission permisson = doc.Permission;
                 Console.WriteLine("已有授权数：" + permisson.Count);
                 ; i <= permisson.Count; i++)
                 {
                     string userId = permisson[i].UserId;
                     Console.WriteLine(userId);
                 }

                 permisson.Add("qx", Microsoft.Office.Core.MsoPermission.msoPermissionFullControl, null);

                 doc.Save();
             }
             catch (Exception ex)
             {
                 Console.WriteLine(ex.Message);
             }
             finally
             {
                 doc.Close();
                 app.Quit();
             }