C#写的读取ISO2709格式数据的DLL_.NET教程_编程技术--HTML5中文学习网

数据

using System;
using System.Collections;

/*
此类的功能,是读取ISO2709数据
得到ISO2709数据三个段,头标/目次/数据
获得字段信息
获得子字段信息
*/

namespace Nosi.Library
{
/// <summary>
/// Class1 的摘要说明。
/// </summary>
public class Marc
{
#region 常量定义

public const char FLDEND = (char)30; // 字段结束符
public const char RECEND = (char)29; // 记录结束符
public const char SUBFLD = (char)31; // 子字段指示符

public const int FLDNAME_LEN = 3; // 字段名长度
public const int MAX_MARCREC_LEN = 100000; // MARC记录的最大长度

#endregion

string m_strMarc = ""; // MARC记录体

public Marc()
{
   //
   // TODO: 在此处添加构造函数逻辑
   //
}
//获得头标
private string GetHeader()
{
   string strHeader = null;
   strHeader = m_strMarc.Substring(0,24);
   return strHeader;
}
//获得目次
private string GetMuci()
{

   char[] charr = m_strMarc.ToCharArray();
   string strMuci = null;
   int i = 24; // 头标字符不再读取
   while(i < m_strMarc.Length)
   {
    strMuci += charr[i].ToString();
    if(charr[i] == FLDEND) break; //发现字段标识
    i++;
   }

return strMuci;

}

// 获得数据区
private string GetData()
{
   string strData = null;
   int iMuci = this.GetMuci().Length;
   int iHeader = this.GetHeader().Length;
   int iMarc = m_strMarc.Length;
   strData = m_strMarc.Substring(iMuci + iHeader,iMarc - iMuci - iHeader);
   return strData;
}

// 获得目次区中的字段名
// -1 error
// 0 no found
// 1 found
private int GetFieldPos(string strFieldName,
   int nIndex,
   out string strFieldPos)
{
   string strMuci = this.GetMuci();
   strFieldPos = null;

   int i = 0;
   int nRet = 0;

if(strMuci == null)
return -1;

   if((strMuci.Length - 1) % 12 != 0) // 减1是由于目次区结束标识符
    return -1; // length error

   do
   {
    if(strMuci.Substring(i,3) == strFieldName)
     nRet ++;
    if(nRet == nIndex)// from zero add
    {
     strFieldPos = strMuci.Substring(i,12);
     break;
    }
    i += 12;
   } while(i<strMuci.Length);

   if (strFieldPos == null)

    return 0; // no found


   return 1;
}

// 通过字段名，字段中出现次数获得字段内容
// 次数从 1 开始计数
// -1 error
// 0 no found
// 1 found
public int GetField(string strFldName,
   int nIndex,
   out string strFld)
{
   strFld = null;

   string strFldPos = null;
   int nRet = this.GetFieldPos(strFldName,nIndex,out strFldPos);
   if (nRet != 1)
    return nRet;
   if(strFldName.Length != 3 )
    return -1; // subfield must 3 chars

   int nLength = int.Parse( strFldPos.Substring(3,4));
   int nBeginPos = int.Parse( strFldPos.Substring(7,5));
   char[] chData = this.GetData().ToCharArray();
   int nPos =0;
   int i = 0;
   while( nPos < chData.Length)
   {
    i += GetCharLength(chData[nPos]);
    if((i >= nBeginPos) && i<= (nBeginPos + nLength))
     strFld += chData[nPos].ToString();
    nPos ++;

   }
   if(strFld == null)
    return 0;
   return 1;
}
//从字段中获得出现次数的子字段
// -1 error
// 0 not found
// 1 found
public int GetSubField(string strFld,
   string strSubName,
   int nIndex,
   out string strSubFld)
{
   strSubFld = null;
   if(strSubName.Length != 1)
    return -1; // subfield'symbol char must 1 char
   if(strFld == null)
    return -1;

   char[] chData = strFld.ToCharArray();
   int nPos = 0;
   bool isNewSub = false;
   int nFound = 0; // 0: not 1: first time found 2: second time found
   while( nPos < chData.Length)
   {
    nPos ++;

    if((chData[nPos-1] == SUBFLD) && (chData[nPos].ToString() == strSubName))
     nFound ++; // found

    if ((nFound == nIndex) && (isNewSub == false))
    {
     if(chData[nPos] == SUBFLD)
     {
      isNewSub = true;
      break;
     }
     strSubFld += chData[nPos].ToString();
    }

   }
   if(strSubFld == null)
    return 0;
   return 1;
}

//从字段组中获得子字段
// -1 error
// 0 not found
// 1 found
public int GetSubField(string strGroup,
   string strSubName,
   out string strSubFld)
{
   strSubFld = null;
   if(strSubName.Length != 1)
    return -1; // subfield'symbol char must 1 char
   if(strGroup == null)
    return -1;

   char[] chData = strGroup.ToCharArray();
   int nPos = 0;
   bool isNewSub = false;
   int nFound = 0; // 0: not 1: first time found 2: second time found
   while( nPos < chData.Length)
   {
    nPos ++;

    if((chData[nPos-1] == SUBFLD) && (chData[nPos].ToString() == strSubName))
     nFound ++; // found

    if (isNewSub == false)
    {
     if(chData[nPos] == SUBFLD)
     {
      isNewSub = true;
      break;
     }
     strSubFld += chData[nPos].ToString();
    }

   }
   if(strSubFld == null)
    return 0;
   return 1;
}

//从字段中获得出现次数字段组
// -1 error
// 0 not found
// 1 found
public int GetFieldGroup(string strFld,
   int nIndex,
   out string strGroup)
{
   strGroup = null;

   if(strFld == null)
    return -1;

   char[] chData = strFld.ToCharArray();
   int nPos = 0;
   string strSplit = "a"; // 一般以a子字段为字段组区分
   int nFound = 0; // 0: not 1: first time found 2: second time found
   while( nPos < chData.Length)
   {
    nPos ++;

    if((chData[nPos-1] == SUBFLD) && (chData[nPos].ToString() == strSplit))
     nFound ++; // found

    if (nFound == nIndex)
     strGroup += chData[nPos].ToString();
    if(nFound > nIndex)
     break;
   }
   if(strGroup == null)
    return 0;
   return 1;
}
//获得字符的长度
//
private int GetCharLength(char ch)
{
   int nLength = 0;

   if((short)ch < 0 || (short)ch > 128)
   {
    nLength += 2;
   }
   else
   {
    nLength = nLength + 1;
   }
   return nLength;
}

public string strMarc
{
   get
   {
    return m_strMarc;
   }
   set
   {
    m_strMarc = value;
   }

}
}
}