在 ETAS INCA 中，有没有办法从 ASAP2Project 中的任意路径快速检索项目？

Question

我正在尝试通过 .NET API 连接到 INCA，以便导航 ASAP2 项目的文件夹结构。具体来说，我想获得一个代表我在下面突出显示的“目标”文件夹的对象。

这被证明是相当棘手的——API 提供了大量名称为“文件夹”的类：Folder、Asap2ProjectFolder 和 IncaFolder。那么，为了检索“目标”文件夹，我需要知道什么？

Answer 1

您的第一个冲动可能是认为 Target 文件夹存在于像 USER A\Demo\Demo03\Foo\Bar\Baz\Target 这样的长路径上。不幸的是，INCA 没有这样做的机制——相反，您必须检索路径的 Database Objects 部分中的最低项目，然后查询该项目以获取 Datasets 路径的一部分。

从数据库根目录，我们需要深入到Demo03，它是一个Asap2Project：

USER A\Demo\Demo03

从 Demo03 中，我们需要向下钻取到 Target，这是一个 Asap2ProjectFolder：

Foo\Bar\Baz\Target

第一部分非常简单——我们只需几行代码就可以连接到 INCA 并获得 Demo03 Asap2Project：

Asap2ProjectFolder targetFolder = null;
Inca myIncaInstance = new Inca();
DataBase myDB = myIncaInstance.GetCurrentDataBase();
DataBaseItem tempItem = myDB.GetItemInFolder("Demo03", "USER A\\Demo");

if ((tempItem != null) && 
    (tempItem.IsAsap2Project()))
   {
   Asap2Project demoProject = (Asap2Project)tempItem;

   // Next step: grab the "Target folder!"
   }

现在，事情变得有些棘手了。

如果我们试图获得像 Demo03_1 这样的 DataSet，我们可以使用像 demoProject.GetDataSetForName("Demo03\\Demo03_1") 这样的调用。问题是，此方法仅适用于 DataSet 类型的对象。所以我们不能用它来检索像Foo\Bar\Baz\Target 这样的文件夹。如果您稍微研究过 API，您可能已经尝试过这样的事情：

Asap2ProjectFolder tempProjFolder = demoProject.GetTopFolderNamed("Foo");
tempItem = tempProjFolder.GetDataBaseItem("Bar\\Baz\\Target");  // Won't work.
tempItem = tempProjFolder.GetSubFolder("Bar\\Baz\\Target");     // This won't either.

事实证明，我们需要更加足智多谋。让我们为 Asap2Project 和 Asap2ProjectFolder 类创建 GetItemInFolder() 扩展方法，这样这些类将具有与 DataBase 类相同的项目检索灵活性：

namespace IncaExtensions
   {
   public static class GetItemInFolderExtensions
      {
      /// <summary>
      /// Gets a DataBaseItem from an Asap2Project in an arbitrary subfolder.
      /// </summary>
      /// <param name="project">The current Asap2Project</param>
      /// <param name="itemName">The name of the item that we want to retrieve</param>
      /// <param name="folderName">The path, delimited by backslashes ('\\')</param>
      /// <returns>A DataBaseItem matching the request.  
      /// If no matching item is found, or if the path is invalid, return null.
      /// </returns>
      public static DataBaseItem GetItemInFolder(this Asap2Project project, 
                                                 string itemName, 
                                                 string folderName)
         {
         DataBaseItem returnItem = null;

         if ((folderName != null) &&
             (itemName != null))
            {
            string folderToken = PluckPathToken(ref folderName);
            Asap2ProjectFolder subFolder = 
               project.GetTopFolderNamed(folderToken);

            if (subFolder != null)
               {
               returnItem = subFolder.GetItemInFolder(itemName, folderName); 
               }
            }

         return returnItem;
         }


      /// <summary>
      /// Recursive call that returns a DataBaseItem in the target path.
      /// </summary>
      /// <param name="folder">The Asap2ProjectFolder to drill down</param>
      /// <param name="itemName">The name of the item that we want to retrieve</param>
      /// <param name="folderName">The path, delimited by backslashes ('\\')</param>
      /// <returns>A DataBaseItem matching the request.  
      /// If no matching item is found, or if the path is invalid, return null.
      /// </returns>
      public static DataBaseItem GetItemInFolder(this Asap2ProjectFolder folder, 
                                                 string itemName, 
                                                 string folderName)
         {
         DataBaseItem returnItem = null;

         if ((folderName != null) &&
             (itemName != null))
            {
            string folderToken = PluckPathToken(ref folderName);
            Asap2ProjectFolder subFolder = 
               (Asap2ProjectFolder)folder.GetSubFolder(folderToken);

            if (subFolder != null)
               {
               returnItem = subFolder.GetItemInFolder(itemName, folderName);
               }
            }
         else
            {
            returnItem = folder.GetDataBaseItem(itemName);
            }

         return returnItem;
         }


      /// <summary>
      /// Removes a backslash-delimited token from a string and shortens the
      /// input string.
      /// </summary>
      /// <param name="folderName">Backslash-delimited path.  This will be 
      /// shortened each time a token is removed.</param>
      /// <returns>The latest path token</returns>
      static string PluckPathToken(ref string folderName)
         {
         int slashIdx = folderName.IndexOf('\\');

         // If folderName has path tokens, extract the first token and
         // shorten folderName accordingly.
         string folderToken = (slashIdx > -1) ? 
            folderName.Substring(0, slashIdx) : folderName;
         folderName = (slashIdx > -1) ? 
            folderName.Substring(slashIdx + 1) : null;

         return folderToken;
         }
      }
   }

这使得从Asap2Project 或Asap2ProjectFolder 中获取项目变得非常容易。要获取 Target 文件夹，我们只需要以下调用：

using IncaExtensions;
...
Asap2ProjectFolder targetFolder = null;
Inca myIncaInstance = new Inca();
DataBase myDB = myIncaInstance.GetCurrentDataBase();
DataBaseItem tempItem = myDB.GetItemInFolder("Demo03", "USER A\\Demo");

if ((tempItem != null) && 
    (tempItem.IsAsap2Project()))
   {
   Asap2Project demoProject = (Asap2Project)tempItem;
   targetFolder = (Asap2ProjectFolder)demoProject.GetItemInFolder("Target", "Foo\\Bar\\Baz");
   }