C#写的读取ISO2709格式数据的DLL

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
{
///

1<summary>   
2/// Class1 的摘要说明。   
3/// </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

  1<strmuci.length); !="3" (nret="" (strfieldpos="null)" )="" +="GetCharLength(chData[nPos]);" -1="" -1;="" 0="" 0;="" 1="" 1;="" 3="" <="" char[]="" chars="" chdata="this.GetData().ToCharArray();" chdata.length)="" error="" found="" getfield(string="" i="" if="" if((i="" if(strfldname.length="" int="" must="" nbeginpos="int.Parse(" nindex,="" nlength="int.Parse(" no="" npos="" nret="this.GetFieldPos(strFldName,nIndex,out" nret;="" out="" public="" return="" strfld="null;" strfld)="" strfldname,="" strfldpos="null;" strfldpos);="" strfldpos.substring(3,4));="" strfldpos.substring(7,5));="" string="" subfield="" while(="" {="" }="" 开始计数="" 次数从="" 通过字段名，字段中出现次数获得字段内容="">= nBeginPos) &amp;&amp; i&lt;= (nBeginPos + nLength))   
  2strFld += chData[nPos].ToString();   
  3nPos ++; 
  4
  5}   
  6if(strFld == null)   
  7return 0;   
  8return 1;   
  9}   
 10//从字段中获得出现次数的子字段   
 11// -1 error   
 12// 0 not found   
 13// 1 found   
 14public int GetSubField(string strFld,   
 15string strSubName,   
 16int nIndex,   
 17out string strSubFld)   
 18{   
 19strSubFld = null;   
 20if(strSubName.Length != 1)   
 21return -1; // subfield'symbol char must 1 char   
 22if(strFld == null)   
 23return -1;   
 24  
 25char[] chData = strFld.ToCharArray();   
 26int nPos = 0;   
 27bool isNewSub = false;   
 28int nFound = 0; // 0: not 1: first time found 2: second time found   
 29while( nPos &lt; chData.Length)   
 30{   
 31nPos ++;   
 32  
 33if((chData[nPos-1] == SUBFLD) &amp;&amp; (chData[nPos].ToString() == strSubName))   
 34nFound ++; // found 
 35
 36if ((nFound == nIndex) &amp;&amp; (isNewSub == false))   
 37{   
 38if(chData[nPos] == SUBFLD)   
 39{   
 40isNewSub = true;   
 41break;   
 42}   
 43strSubFld += chData[nPos].ToString();   
 44} 
 45
 46}   
 47if(strSubFld == null)   
 48return 0;   
 49return 1;   
 50} 
 51
 52//从字段组中获得子字段   
 53// -1 error   
 54// 0 not found   
 55// 1 found   
 56public int GetSubField(string strGroup,   
 57string strSubName,   
 58out string strSubFld)   
 59{   
 60strSubFld = null;   
 61if(strSubName.Length != 1)   
 62return -1; // subfield'symbol char must 1 char   
 63if(strGroup == null)   
 64return -1;   
 65  
 66char[] chData = strGroup.ToCharArray();   
 67int nPos = 0;   
 68bool isNewSub = false;   
 69int nFound = 0; // 0: not 1: first time found 2: second time found   
 70while( nPos &lt; chData.Length)   
 71{   
 72nPos ++;   
 73  
 74if((chData[nPos-1] == SUBFLD) &amp;&amp; (chData[nPos].ToString() == strSubName))   
 75nFound ++; // found 
 76
 77if (isNewSub == false)   
 78{   
 79if(chData[nPos] == SUBFLD)   
 80{   
 81isNewSub = true;   
 82break;   
 83}   
 84strSubFld += chData[nPos].ToString();   
 85} 
 86
 87}   
 88if(strSubFld == null)   
 89return 0;   
 90return 1;   
 91} 
 92
 93//从字段中获得出现次数字段组   
 94// -1 error   
 95// 0 not found   
 96// 1 found   
 97public int GetFieldGroup(string strFld,   
 98int nIndex,   
 99out string strGroup)   
100{   
101strGroup = null;   
102  
103if(strFld == null)   
104return -1;   
105  
106char[] chData = strFld.ToCharArray();   
107int nPos = 0;   
108string strSplit = "a"; // 一般以a子字段为字段组区分   
109int nFound = 0; // 0: not 1: first time found 2: second time found   
110while( nPos &lt; chData.Length)   
111{   
112nPos ++;   
113  
114if((chData[nPos-1] == SUBFLD) &amp;&amp; (chData[nPos].ToString() == strSplit))   
115nFound ++; // found 
116
117if (nFound == nIndex)   
118strGroup += chData[nPos].ToString();   
119if(nFound &gt; nIndex)   
120break;   
121}   
122if(strGroup == null)   
123return 0;   
124return 1;   
125}   
126//获得字符的长度   
127//   
128private int GetCharLength(char ch)   
129{   
130int nLength = 0;   
131  
132if((short)ch &lt; 0 || (short)ch &gt; 128)   
133{   
134nLength += 2;   
135}   
136else   
137{   
138nLength = nLength + 1;   
139}   
140return nLength;   
141} 
142
143public string strMarc   
144{   
145get   
146{   
147return m_strMarc;   
148}   
149set   
150{   
151m_strMarc = value;   
152} 
153
154}   
155}   
156}</strmuci.length);>