ASP.NET常见异常处理示例

• 将指定的年月日转初始化为DateTime新的实例(Nop.Admin.Controllers.OrderController.ParseProductAttributes)

  case AttributeControlType.Datepicker:
                          {
                              var day = form[controlId + "_day"];
                              var month = form[controlId + "_month"];
                              var year = form[controlId + "_year"];
                              DateTime? selectedDate = null;
                              try
                              {
                                  selectedDate = new DateTime(Int32.Parse(year), Int32.Parse(month), Int32.Parse(day));
                              }
                              catch { }
                              if (selectedDate.HasValue)
                              {
                                  attributesXml = _productAttributeParser.AddProductAttribute(attributesXml,
                                      attribute, selectedDate.Value.ToString("D"));
                              }
                          }
                          break;

• 能否出订单信息(srcPresentationNop.WebAdministrationControllersOrderController.cs(1346))

try
            {
                byte[] bytes = _exportManager.ExportOrdersToXlsx(orders);
                return File(bytes, MimeTypes.TextXlsx, "orders.xlsx");
            }
            catch (Exception exc)
            {
                ErrorNotification(exc);
                return RedirectToAction("List");
            }

• 发送HTTP请求(srcPluginsNop.Plugin.ExchangeRate.EcbExchangeEcbExchangeRateProvider.cs(60))

  //get exchange rates to euro from European Central Bank
              var request = (HttpWebRequest)WebRequest.Create("http://www.ecb.int/stats/eurofxref/eurofxref-daily.xml");
              try
              {
                  using (var response = request.GetResponse())
                  {
                      //load XML document
                      var document = new XmlDocument();
                      document.Load(response.GetResponseStream());
  
                      //add namespaces
                      var namespaces = new XmlNamespaceManager(document.NameTable);
                      namespaces.AddNamespace("ns", "http://www.ecb.int/vocabulary/2002-08-01/eurofxref");
                      namespaces.AddNamespace("gesmes", "http://www.gesmes.org/xml/2002-08-01");
  
                      //get daily rates
                      var dailyRates = document.SelectSingleNode("gesmes:Envelope/ns:Cube/ns:Cube", namespaces);
                      DateTime updateDate;
                      if (!DateTime.TryParseExact(dailyRates.Attributes["time"].Value, "yyyy-MM-dd", null, DateTimeStyles.None, out updateDate))
                          updateDate = DateTime.UtcNow;
  
                      foreach (XmlNode currency in dailyRates.ChildNodes)
                      {
                          //get rate
                          decimal currencyRate;
                          if (!decimal.TryParse(currency.Attributes["rate"].Value, out currencyRate))
                              continue;
  
                          ratesToEuro.Add(new Core.Domain.Directory.ExchangeRate()
                          {
                              CurrencyCode = currency.Attributes["currency"].Value,
                              Rate = currencyRate,
                              UpdatedOn = updateDate
                          });
                      }
                  }
              }
              catch (WebException ex)
              {
                  _logger.Error("ECB exchange rate provider", ex);
              }

• EF操作(srcLibrariesNop.DataEfRepository.cs(182))

  try
              {
                  if (entities == null)
                      throw new ArgumentNullException("entities");
  
                  foreach (var entity in entities)
                      this.Entities.Remove(entity);
  
                  this._context.SaveChanges();
              }
              catch (DbEntityValidationException dbEx)
              {
                  throw new Exception(GetFullErrorText(dbEx), dbEx);
              }

• srcLibrariesNop.CoreWebHelper.cs(46)

          protected virtual Boolean IsRequestAvailable(HttpContextBase httpContext)
          {
              if (httpContext == null)
                  return false;
  
              try
              {
                  if (httpContext.Request == null)
                      return false;
              }
              catch (HttpException)
              {
                  return false;
              }
  
              return true;
          }

• srcLibrariesNop.CorePluginsPluginManager.cs(434)

  try
                  {
                      File.Copy(plug.FullName, shadowCopiedPlug.FullName, true);
                  }
                  catch (IOException)
                  {
                      Debug.WriteLine(shadowCopiedPlug.FullName + " is locked, attempting to rename");
                      //this occurs when the files are locked,
                      //for some reason devenv locks plugin files some times and for another crazy reason you are allowed to rename them
                      //which releases the lock, so that it what we are doing here, once it's renamed, we can re-shadow copy
                      try
                      {
                          var oldFile = shadowCopiedPlug.FullName + Guid.NewGuid().ToString("N") + ".old";
                          File.Move(shadowCopiedPlug.FullName, oldFile);
                      }
                      catch (IOException exc)
                      {
                          throw new IOException(shadowCopiedPlug.FullName + " rename failed, cannot initialize plugin", exc);
                      }
                      //ok, we've made it this far, now retry the shadow copy
                      File.Copy(plug.FullName, shadowCopiedPlug.FullName, true);
                  }