C#读取csv格式文件

一、CSV文件规则

 

1 开头是不留空，以行为单位。

2 可含或不含列名，含列名则居文件第一行。

3 一行数据不跨行，无空行。

4 以半角逗号（即,）作分隔符，列为空也要表达其存在。

5 列内容如存在半角逗号（即,）则用半角引号（即','）将该字段值包含起来。

6 列内容如存在半角引号（即"）则应替换成半角双引号（""）转义，并用半角引号（即""）将该字段值包含起来。

7 文件读写时引号，逗号操作规则互逆。

8 内码格式不限，可为 ASCII、Unicode 或者其他。

9 不支持特殊字符

 

 

 

二、C#读取csv文件的方法

 

 

C# 代码   复制

//读CSV文件类,读取指定的CSV文件，可以导出DataTable

    public class CsvStreamReader

{ 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 CsvStreamReader() { 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 CsvStreamReader(string fileName) { this.rowAL = new ArrayList(); this.fileName = fileName; this.encoding = Encoding.Default; LoadCsvFile(); } /// <summary> /// /// </summary> /// <param name="fileName">文件名,包括文件路径</param> /// <param name="encoding">文件编码</param> public CsvStreamReader(string fileName, Encoding encoding) { this.rowAL = new ArrayList(); this.fileName = fileName; this.encoding = encoding; LoadCsvFile(); } /// <summary> /// 文件名,包括文件路径 /// </summary> public string FileName { set { this.fileName = value; LoadCsvFile(); } } /// <summary> /// 文件编码 /// </summary> public Encoding FileEncoding { set { this.encoding = value; } } /// <summary> /// 获取行数 /// </summary> public int RowCount { get { return this.rowAL.Count; } } /// <summary> /// 获取列数 /// </summary> public int ColCount { 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> /// 获取某行某列的数据 /// 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] { get { //数据有效性验证 CheckRowValid(row); CheckColValid(col); ArrayList colAL = (ArrayList)this.rowAL[row - 1]; //如果请求列数据大于当前行的列时,返回空值 if (colAL.Count < col) { return ""; } return colAL[col - 1].ToString(); } } /// <summary> /// 根据最小行，最大行，最小列，最大列，来生成一个DataTable类型的数据 /// 行等于1代表第一行 /// 列等于1代表第一列 /// maxrow: -1代表最大行 /// maxcol: -1代表最大列 /// </summary> public DataTable this[int minRow, int maxRow, int minCol, int maxCol] { get { //数据有效性验证 CheckRowValid(minRow); CheckMaxRowValid(maxRow); CheckColValid(minCol); CheckMaxColValid(maxCol); if (maxRow == -1) { maxRow = RowCount; } if (maxCol == -1) { maxCol = ColCount; } if (maxRow < minRow) { throw new Exception("最大行数不能小于最小行数"); } if (maxCol < minCol) { throw new Exception("最大列数不能小于最小列数"); } DataTable csvDT = new DataTable(); int i; int col; int row; //增加列 for (i = minCol; i <= maxCol; i++) { csvDT.Columns.Add(i.ToString()); } for (row = minRow; row <= maxRow; row++) { DataRow csvDR = csvDT.NewRow(); i = 0; for (col = minCol; col <= maxCol; col++) { csvDR[i] = this[row, col]; i++; } csvDT.Rows.Add(csvDR); } return csvDT; } } /// <summary> /// 检查行数是否是有效的 /// </summary> /// <param name="col"></param> private void CheckRowValid(int row) { if (row <= 0) { throw new Exception("行数不能小于0"); } if (row > RowCount) { throw new Exception("没有当前行的数据"); } } /// <summary> /// 检查最大行数是否是有效的 /// </summary> /// <param name="col"></param> private void CheckMaxRowValid(int maxRow) { if (maxRow <= 0 && maxRow != -1) { throw new Exception("行数不能等于0或小于-1"); } if (maxRow > RowCount) { throw new Exception("没有当前行的数据"); } } /// <summary> /// 检查列数是否是有效的 /// </summary> /// <param name="col"></param> private void CheckColValid(int col) { if (col <= 0) { throw new Exception("列数不能小于0"); } if (col > ColCount) { throw new Exception("没有当前列的数据"); } } /// <summary> /// 检查检查最大列数是否是有效的 /// </summary> /// <param name="col"></param> private void CheckMaxColValid(int maxCol) { if (maxCol <= 0 && maxCol != -1) { throw new Exception("列数不能等于0或小于-1"); } if (maxCol > ColCount) { throw new Exception("没有当前列的数据"); } } /// <summary> /// 载入CSV文件 /// </summary> private void LoadCsvFile() { //对数据的有效性进行验证 if (this.fileName == null) { throw new Exception("请指定要载入的CSV文件名"); } else if (!File.Exists(this.fileName)) { throw new Exception("指定的CSV文件不存在"); } else { } if (this.encoding == null) { this.encoding = Encoding.Default; } StreamReader sr = new StreamReader(this.fileName, this.encoding); string csvDataLine; csvDataLine = ""; while (true) { string fileDataLine; fileDataLine = sr.ReadLine(); if (fileDataLine == null) { break; } if (csvDataLine == "") { csvDataLine = fileDataLine;//GetDeleteQuotaDataLine(fileDataLine); } else { csvDataLine += "\\r\\n" + fileDataLine;//GetDeleteQuotaDataLine(fileDataLine); } //如果包含偶数个引号，说明该行数据中出现回车符或包含逗号 if (!IfOddQuota(csvDataLine)) { AddNewDataLine(csvDataLine); csvDataLine = ""; } } sr.Close(); //数据行出现奇数个引号 if (csvDataLine.Length > 0) { throw new Exception("CSV文件的格式有错误"); } } /// <summary> /// 获取两个连续引号变成单个引号的数据行 /// </summary> /// <param name="fileDataLine">文件数据行</param> /// <returns></returns> private string GetDeleteQuotaDataLine(string fileDataLine) { return fileDataLine.Replace("\\"\\"", "\\""); } /// <summary> /// 判断字符串是否包含奇数个引号 /// </summary> /// <param name="dataLine">数据行</param> /// <returns>为奇数时，返回为真；否则返回为假</returns> private bool IfOddQuota(string dataLine) { int quotaCount; bool oddQuota; quotaCount = 0; for (int i = 0; i < dataLine.Length; i++) { if (dataLine[i] == '\\"') { quotaCount++; } } oddQuota = false; if (quotaCount % 2 == 1) { oddQuota = true; } return oddQuota; } /// <summary> /// 判断是否以奇数个引号开始 /// </summary> /// <param name="dataCell"></param> /// <returns></returns> private bool IfOddStartQuota(string dataCell) { int quotaCount; bool oddQuota; quotaCount = 0; for (int i = 0; i < dataCell.Length; i++) { if (dataCell[i] == '\\"') { quotaCount++; } else { break; } } oddQuota = false; if (quotaCount % 2 == 1) { oddQuota = true; } return oddQuota; } /// <summary> /// 判断是否以奇数个引号结尾 /// </summary> /// <param name="dataCell"></param> /// <returns></returns> private bool IfOddEndQuota(string dataCell) { int quotaCount; bool oddQuota; quotaCount = 0; for (int i = dataCell.Length - 1; i >= 0; i--) { if (dataCell[i] == '\\"') { quotaCount++; } else { break; } } oddQuota = false; if (quotaCount % 2 == 1) { oddQuota = true; } return oddQuota; } /// <summary> /// 加入新的数据行 /// </summary> /// <param name="newDataLine">新的数据行</param> private void AddNewDataLine(string newDataLine) { //System.Diagnostics.Debug.WriteLine("NewLine:" + newDataLine); ////return; ArrayList colAL = new ArrayList(); string[] dataArray = newDataLine.Split(','); bool oddStartQuota; //是否以奇数个引号开始 string cellData; oddStartQuota = false; cellData = ""; for (int i = 0; i < dataArray.Length; i++) { if (oddStartQuota) { //因为前面用逗号分割,所以要加上逗号 cellData += "," + dataArray[i]; //是否以奇数个引号结尾 if (IfOddEndQuota(dataArray[i])) { colAL.Add(GetHandleData(cellData)); oddStartQuota = false; continue; } } else { //是否以奇数个引号开始 if (IfOddStartQuota(dataArray[i])) { //是否以奇数个引号结尾,不能是一个双引号,并且不是奇数个引号 if (IfOddEndQuota(dataArray[i]) && dataArray[i].Length > 2 && !IfOddQuota(dataArray[i])) { colAL.Add(GetHandleData(dataArray[i])); oddStartQuota = false; continue; } else { oddStartQuota = true; cellData = dataArray[i]; continue; } } else { colAL.Add(GetHandleData(dataArray[i])); } } } if (oddStartQuota) { throw new Exception("数据格式有问题"); } this.rowAL.Add(colAL); } /// <summary> /// 去掉格子的首尾引号，把双引号变成单引号 /// </summary> /// <param name="fileCellData"></param> /// <returns></returns> private string GetHandleData(string fileCellData) { if (fileCellData == "") { return ""; } if (IfOddStartQuota(fileCellData)) { if (IfOddEndQuota(fileCellData)) { return fileCellData.Substring(1, fileCellData.Length - 2).Replace("\\"\\"", "\\""); //去掉首尾引号，然后把双引号变成单引号 } else { throw new Exception("数据引号无法匹配" + fileCellData); } } else { //考虑形如"" """" """""" if (fileCellData.Length > 2 && fileCellData[0] == '\\"') { fileCellData = fileCellData.Substring(1, fileCellData.Length - 2).Replace("\\"\\"", "\\""); //去掉首尾引号，然后把双引号变成单引号 } } return fileCellData; } }