扩展平面文件反汇编程序管道组件

下面的示例演示如何创建自定义拆装器以便解析用 UTF-7 编码的平面文件文档。 为了处理 UTF-7 文档，组件继承自 FFDasmComp 类，然后重写其 GetDataReader 方法。

using System;  
using System.Text;  
using System.IO;  
using Microsoft.BizTalk.Message.Interop;  
using Microsoft.BizTalk.Component.Interop;  
using Microsoft.BizTalk.ParsingEngine;  
using Microsoft.BizTalk.Component;  
using System.Runtime.InteropServices;  
  
namespace Microsoft.BizTalk.Test  
{  
   /// <summary>  
   /// Implements FF disassembler which always uses UTF-7 encoding.  
   /// </summary>  
   [ComponentCategory(CategoryTypes.CATID_PipelineComponent)]  
   [ComponentCategory(CategoryTypes.CATID_DisassemblingParser)]  
   [ComponentCategory(CategoryTypes.CATID_Streamer)]  
   [Guid("A6E5F54F-7902-4e1a-84D8-5C7584F0ECF2")]  
   public class Utf7FFDasm :   
      FFDasmComp,  
      IBaseComponent  
   {  
      /// <summary>  
      /// Initializes a Utf7FFAsmDasm instance.  
      /// </summary>  
      public Utf7FFDasm()  
      {  
      }  
  
      /// <summary>  
      /// Name property  
      /// </summary>  
      public new string Name   
      {  
         get   
         {  
            return "UTF-7 FlatFile Disassembler";  
         }  
      }  
  
      /// <summary>  
      /// Version property  
      /// </summary>  
      public new string Version   
      {  
         get   
         {  
            return "1.0";  
         }  
      }  
  
      /// <summary>  
      /// Description property  
      /// </summary>  
      public new string Description   
      {  
         get   
         {  
            return "UTF-7 FlatFile Disassembler";  
         }  
      }  
  
      /// <summary>  
      /// Gets a data reader instance  
      /// </summary>  
      /// <param name="dataStream">Data stream</param>  
      /// <param name="dataEncoding">Data encoding</param>  
      /// <param name="detectEncodingFromByteOrderMarks">Detect encoding from a byte order mark</param>  
      /// <returns>IDataReader instance</returns>  
      protected override IDataReader GetDataReader(Stream dataStream, Encoding dataEncoding, bool detectEncodingFromByteOrderMarks)  
      {  
         // Delegate call to the base implementation passing fixed UTF-7 encoding  
            return base.GetDataReader(dataStream, Encoding.UTF7, false);  
      }  
   }  
}  

示例

下面的示例演示如何创建自定义拆装器以便执行平面文件交换的事务处理。 自定义拆装器与标准平面文件拆装器的不同之处在于：前者在整个输入交换都完全处理前，并不生成任何已拆装的文档。 此组件实现继承自 FFDasmComp 类，并重写 GetNext 方法。 首次调用 GetNext 方法时，它会处理交换中的所有消息，将它们存储在 ArrayList 中，并从 ArrayList 返回第一条消息。 在后续调用中，它将从 ArrayList 返回下一条消息。

注意

在下面的代码示例中实现 GetNext() 方法的方式并不适合于处理大型文档，因为它将在内存中保留整个交换。 将此技术用于大型文档可能会用尽内存资源，从而导致性能下降或出现不稳定的行为。

using System;  
using System.Collections;  
using System.Runtime.InteropServices;  
using Microsoft.BizTalk.Message.Interop;  
using Microsoft.BizTalk.Component.Interop;  
using Microsoft.BizTalk.Component;  
  
namespace Microsoft.BizTalk.Component  
{  
   /// <summary>  
   /// Summary description for Class1.  
   /// </summary>  
   [ComponentCategory(CategoryTypes.CATID_PipelineComponent)]  
   [ComponentCategory(CategoryTypes.CATID_DisassemblingParser)]  
   [Guid("EB4714A8-FD97-43de-84E2-E011648F349B")]  
   public class TransactionalFFDasm :   
      FFDasmComp,  
      IBaseComponent,  
      IDisassemblerComponent  
   {  
      public TransactionalFFDasm()  
      {  
      }  
  
      #region IBaseComponent Members  
  
      public new string Description  
      {  
         get  
         {  
            return "Transactional Flat File Disassembler";  
         }  
      }  
  
      public new string Name  
      {  
         get  
         {  
            return "Transactional Flat File Disassembler";  
         }  
      }  
  
      public new string Version  
      {  
         get  
         {  
            return "1.0";  
         }  
      }  
  
      #endregion  
  
      #region IDisassemblerComponent Members  
  
      public new void Disassemble(IPipelineContext pContext, IBaseMessage pInMsg)  
      {  
         base.Disassemble(pContext, pInMsg);  
      }  
  
      public new IBaseMessage GetNext(IPipelineContext pContext)  
      {  
         // Check if don't need to stop collecting messages  
         if (currentMessage == 0)  
         {  
            messageInterchange = new ArrayList();  
            currentMessage = 0;  
  
            // Collect messages from the standard disassembler  
            IBaseMessage disassembledMessage = null;  
            while ((disassembledMessage = base.GetNext(pContext)) != null)  
            {  
               byte[] buffer = new byte[4096];  
               int count = 0;  
  
               // Create a new memory stream to contain the disassembled message.  
               MemoryStream messageStream = new MemoryStream();  
  
               // Get a stream pointer to the disassembled stream.  
               Stream disassembledStream = disassembledMessage.BodyPart.GetOriginalDataStream();  
  
               // Write the disassembled message to the memory stream  
               while (0 != (count == disassembledStream.Read(buffer, 0, 4096)))  
               {  
                  messageStream.Write(buffer, 0, count);  
               } // end-while  
  
               // Rewind the stream to the beginning  
               messageStream.Seek(0, SeekOrigin.Begin);  
  
               // Replace the stream on the disassembled message with the memory stream.  
               disassembledMessage.BodyPart.data = messageStream;  
  
               // Add this message to the ArrayList of messages.  
               messageInterchange.Add(disassembledMessage);  
            } // end-while  
  
            // Check if no messages were collected, just return nothing  
            if (0 == messageInterchange.Count)  
               return null;  
         } // end-if  
  
         // Check if all collected messages are returned  
         if (currentMessage == messageInterchange.Count)  
            return null;  
  
         // Return the current collected message  
         return (IBaseMessage)messageInterchange[currentMessage++];  
      } // end-method GetNext()  
  
      #endregion  
  
      private ArrayList messageInterchange = null;  
      private int currentMessage = 0;  
   }  
}  
  

另请参阅

开发拆装管道组件