CsvFileStream.cs
public class CsvFileStream
{
TextReader stream;
bool EOS = false;
bool EOL = false; public CsvFileStream(TextReader s)
{
stream = s;
} public string[] GetNextRow()
{
ArrayList row = new ArrayList();
while (true)
{
string item = GetNextItem();
if (item == null)
return row.Count == ? null : (string[])row.ToArray(typeof(string));
row.Add(item);
}
} string GetNextItem()
{
if (EOL)
{
// previous item was last in line, start new line
EOL = false;
return null;
} bool quoted = false;
bool predata = true;
bool postdata = false;
StringBuilder sb = new StringBuilder(); while (true)
{
char c = GetNextChar(true);
if (EOS)
return sb.Length > ? sb.ToString() : null; if ((postdata || !quoted) && c == ',')
// end of item, return
return sb.ToString(); if ((predata || postdata || !quoted) && (c == '\x0A' || c == '\x0D'))
{
// we are at the end of the line, eat newline characters and exit
EOL = true;
if (c == '\x0D' && GetNextChar(false) == '\x0A')
// new line sequence is 0D0A
GetNextChar(true);
return sb.ToString();
} if (predata && c == ' ')
// whitespace preceeding data, discard
continue; if (predata && c == '"')
{
// quoted data is starting
quoted = true;
predata = false;
continue;
} if (predata)
{
// data is starting without quotes
predata = false;
sb.Append(c);
continue;
} if (c == '"' && quoted)
{
if (GetNextChar(false) == '"')
// double quotes within quoted string means add a quote
sb.Append(GetNextChar(true));
else
// end-quote reached
postdata = true;
continue;
} // all cases covered, character must be data
sb.Append(c);
}
} char[] buffer = new char[];
int pos = ;
int length = ; char GetNextChar(bool eat)
{
if (pos >= length)
{
length = stream.ReadBlock(buffer, , buffer.Length);
if (length == )
{
EOS = true;
return '\0';
}
pos = ;
}
if (eat)
return buffer[pos++];
else
return buffer[pos];
}
}
CsvFileWriter.cs
public class CsvFileWriter
{
private ArrayList rowAL; //行链表,CSV文件的每一行就是一个链
private string fileName; //文件名
private Encoding encoding; //编码 public CsvFileWriter()
{
this.rowAL = new ArrayList();
this.fileName = "";
this.encoding = Encoding.Default;
} /// <summary>
///
/// </summary>
/// <param name="fileName">文件名,包括文件路径</param>
public CsvFileWriter(string fileName)
{
this.rowAL = new ArrayList();
this.fileName = fileName;
this.encoding = Encoding.Default;
} /// <summary>
///
/// </summary>
/// <param name="fileName">文件名,包括文件路径</param>
/// <param name="encoding">文件编码</param>
public CsvFileWriter(string fileName, Encoding encoding)
{
this.rowAL = new ArrayList();
this.fileName = fileName;
this.encoding = encoding;
} /// <summary>
/// row:行,row = 1代表第一行
/// col:列,col = 1代表第一列
/// </summary>
public string this[int row, int col]
{
set
{
//对行进行判断
if (row <= )
{
throw new Exception("行数不能小于0");
}
else if (row > this.rowAL.Count) //如果当前列链的行数不够，要补齐
{
for (int i = this.rowAL.Count + ; i <= row; i++)
{
this.rowAL.Add(new ArrayList());
}
}
else
{
}
//对列进行判断
if (col <= )
{
throw new Exception("列数不能小于0");
}
else
{
ArrayList colTempAL = (ArrayList)this.rowAL[row - ]; //扩大长度
if (col > colTempAL.Count)
{
for (int i = colTempAL.Count; i <= col; i++)
{
colTempAL.Add("");
}
}
this.rowAL[row - ] = colTempAL;
}
//赋值
ArrayList colAL = (ArrayList)this.rowAL[row - ]; colAL[col - ] = value;
this.rowAL[row - ] = colAL;
}
} /// <summary>
/// 文件名,包括文件路径
/// </summary>
public string FileName
{
set
{
this.fileName = value;
}
} /// <summary>
/// 文件编码
/// </summary> public Encoding FileEncoding
{
set
{
this.encoding = value;
}
} /// <summary>
/// 获取当前最大行
/// </summary>
public int CurMaxRow
{
get
{
return this.rowAL.Count;
}
} /// <summary>
/// 获取最大列
/// </summary>
public int CurMaxCol
{
get
{
int maxCol; maxCol = ;
for (int i = ; i < this.rowAL.Count; i++)
{
ArrayList colAL = (ArrayList)this.rowAL[i]; maxCol = (maxCol > colAL.Count) ? maxCol : colAL.Count;
} return maxCol;
}
} /// <summary>
/// 添加表数据到CSV文件中
/// </summary>
/// <param name="dataDT">表数据</param>
/// <param name="beginCol">从第几列开始,beginCol = 1代表第一列</param>
public void AddData(DataTable dataDT, int beginCol)
{
if (dataDT == null)
{
throw new Exception("需要添加的表数据为空");
}
int curMaxRow; curMaxRow = this.rowAL.Count;
for (int i = ; i < dataDT.Rows.Count; i++)
{
for (int j = ; j < dataDT.Columns.Count; j++)
{
this[curMaxRow + i + , beginCol + j] = dataDT.Rows[i][j].ToString();
}
}
} /// <summary>
/// 保存数据,如果当前硬盘中已经存在文件名一样的文件，将会覆盖
/// </summary>
public void Save()
{
//对数据的有效性进行判断
if (this.fileName == null)
{
throw new Exception("缺少文件名");
}
else if (File.Exists(this.fileName))
{
File.Delete(this.fileName);
}
if (this.encoding == null)
{
this.encoding = Encoding.Default;
}
System.IO.StreamWriter sw = new StreamWriter(this.fileName, false, this.encoding); for (int i = ; i < this.rowAL.Count; i++)
{
sw.WriteLine(ConvertToSaveLine((ArrayList)this.rowAL[i]));
} sw.Close();
} /// <summary>
/// 保存数据,如果当前硬盘中已经存在文件名一样的文件，将会覆盖
/// </summary>
/// <param name="fileName">文件名,包括文件路径</param>
public void Save(string fileName)
{
this.fileName = fileName;
Save();
} /// <summary>
/// 保存数据,如果当前硬盘中已经存在文件名一样的文件，将会覆盖
/// </summary>
/// <param name="fileName">文件名,包括文件路径</param>
/// <param name="encoding">文件编码</param>
public void Save(string fileName, Encoding encoding)
{
this.fileName = fileName;
this.encoding = encoding;
Save();
} /// <summary>
/// 转换成保存行
/// </summary>
/// <param name="colAL">一行</param>
/// <returns></returns>
private string ConvertToSaveLine(ArrayList colAL)
{
string saveLine; saveLine = "";
for (int i = ; i < colAL.Count; i++)
{
saveLine += ConvertToSaveCell(colAL[i].ToString());
//格子间以逗号分割
if (i < colAL.Count - )
{
saveLine += ",";
}
} return saveLine;
} /// <summary>
/// 字符串转换成CSV中的格子
/// 双引号转换成两个双引号，然后首尾各加一个双引号
/// 这样就不需要考虑逗号及换行的问题
/// </summary>
/// <param name="cell">格子内容</param>
/// <returns></returns>
private string ConvertToSaveCell(string cell)
{
cell = cell.Replace("\"","\"\""); return "\"" + cell + "\"";
//return "";
}
}
CsvFileReader.cs
public class CsvFileReader
{
public static DataTable Parse(string data, bool headers)
{
return Parse(new StringReader(data), headers);
} public static DataTable Parse(string data)
{
return Parse(new StringReader(data));
} public static DataTable Parse(TextReader stream)
{
return Parse(stream, false);
} public static DataTable Parse(TextReader stream, bool headers)
{
DataTable table = new DataTable(); CsvFileStream csv = new CsvFileStream(stream);
string[] row = csv.GetNextRow();
if (row == null) return null; if (headers)
{
foreach (string header in row)
{
if (header != null && header.Length > && !table.Columns.Contains(header))
table.Columns.Add(header, typeof(string));
else
table.Columns.Add(GetNextColumnHeader(table), typeof(string));
}
row = csv.GetNextRow();
} while (row != null)
{
while (row.Length > table.Columns.Count)
table.Columns.Add(GetNextColumnHeader(table), typeof(string));
table.Rows.Add(row);
row = csv.GetNextRow();
}
return table;
} static string GetNextColumnHeader(DataTable table)
{
int c = ;
while (true)
{
string h = "Column" + c++;
if (!table.Columns.Contains(h))
return h;
}
}
}
eg.
TextReader reader = new StreamReader(@"D:\test.csv");
DataTable dt = CsvFileReader.Parse(reader, false);