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 == 0 ? 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 > 0 ? 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[4096]; int pos = 0; int length = 0; char GetNextChar(bool eat) { if (pos >= length) { length = stream.ReadBlock(buffer, 0, buffer.Length); if (length == 0) { EOS = true; return ' '; } pos = 0; } 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 <= 0) { 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 + 1; i <= row; i++) { this.rowAL.Add(new ArrayList()); } } else { } //对列进行判断 if (col <= 0) { throw new Exception("列数不能小于0"); } else { ArrayList colTempAL = (ArrayList)this.rowAL[row - 1]; //扩大长度 if (col > colTempAL.Count) { for (int i = colTempAL.Count; i <= col; i++) { colTempAL.Add(""); } } this.rowAL[row - 1] = colTempAL; } //赋值 ArrayList colAL = (ArrayList)this.rowAL[row - 1]; colAL[col - 1] = value; this.rowAL[row - 1] = 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 = 0; for (int i = 0; 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 = 0; i < dataDT.Rows.Count; i++) { for (int j = 0; j < dataDT.Columns.Count; j++) { this[curMaxRow + i + 1, 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 = 0; 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 = 0; i < colAL.Count; i++) { saveLine += ConvertToSaveCell(colAL[i].ToString()); //格子间以逗号分割 if (i < colAL.Count - 1) { 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 > 0 && !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 = 1; while (true) { string h = "Column" + c++; if (!table.Columns.Contains(h)) return h; } } }
eg.
TextReader reader = new StreamReader(@"D: est.csv"); DataTable dt = CsvFileReader.Parse(reader, false);