项目中比较多的会对文件进行操作，例如文件的上传下载，文件的压缩和解压等IO操作。在.NET项目中较多的会使用DataSet，DataTable进行数据的缓存。

项目中对文本文件的操作比较简单，但是如果需要将文本文件的内容写入系统的缓存中，操作起来，会稍微的繁琐一些。现在总结一个较为通用的方法，将文本文件的内容缓存进入DataSet数据集中。

private DataSet _iifSet;/// <summary>/// 将文本文件转化为DataSet/// </summary>/// <param name="filePath"></param>/// <returns></returns>public DataSet Parse(string filePath){if (string.IsNullOrEmpty(filePath)){throw new ArgumentNullException(filePath);}
try{_iifSet = new DataSet();var fileText = System.IO.File.ReadAllText(filePath);var lines = fileText.Split('\n');CreateTables(lines, _iifSet);FillSet(lines, _iifSet);return _iifSet;}catch (IOException ex){throw new IOException(ex.Message);}}/// <summary>/// 读取行数组并将其解析为数据集的表/// </summary>/// <param name="lines">String iif文件中的行数组</param>/// <param name="set"></param>private void FillSet(IReadOnlyList<string> lines, DataSet set){for (var i = 0; i < lines.Count; i++){if (IsTableHeader(lines[i])){continue;}if (lines[i] == "" || lines[i] == "\r" || lines[i] == "\n\r" || lines[i] == "\n"){continue;}if (lines[i].IndexOf(";__IMPORTED__", StringComparison.Ordinal) != -1){continue;}var line = lines[i];while (!IsFullLine(line, set)){i++;line += lines[i];}ParseRecord(line, set);}}/// <summary>/// 解析记录/// </summary>/// <param name="line"></param>/// <param name="set"></param>private void ParseRecord(string line, DataSet set){if (IsTableHeader(line)){return;}var tablename = line.Split('\t')[0];var parameters = CreateDataRowParams(line, set.Tables[tablename].Columns.Count);if (parameters.Length > 0)set.Tables[tablename].Rows.Add(parameters);}private bool IsFullLine(string line, DataSet set){if (IsTableHeader(line)){return true;}var values = line.Split('\t').Length;var tableName = line.Split('\t')[0];var columns = set.Tables[tableName].Columns.Count;return values >= columns;}private bool IsTableHeader(string tab){return tab.StartsWith("!");}/// <summary>/// 创建datatable/// </summary>/// <param name="lines"></param>/// <param name="set"></param>private void CreateTables(IReadOnlyList<string> lines, DataSet set){foreach (var t in lines.Where(IsTableHeader)){set.Tables.Add(CreateTable(t));}}private DataTable CreateTable(string line){var values = line.Split('\t');values[0] = values[0].Substring(1);var dt = new DataTable(values[0]);values[0] = null;foreach (var name in values){if (string.IsNullOrEmpty(name))continue;var dc = new DataColumn(name, typeof(string));try{dt.Columns.Add(dc);}catch (DuplicateNameException){dc = new DataColumn(name + "_duplicateCol" + dt.Columns.Count);dt.Columns.Add(dc);}}return dt;}public string GetTableName(string line){var values = line.Split('\t');if (values[0].StartsWith("!")){values[0] = values[0].Substring(1);}return values[0];}public readonly static object[] EmptyStringArray = { };private object[] CreateDataRowParams(string line, int maxLength){var raw = line.Split('\t');var length = raw.Length - 1;if (length == 0 || maxLength == 0)return EmptyStringArray;if (length > maxLength)length = maxLength;var values = new string[length];for (var i = 0; i < length; i++){values[i] = raw[i + 1];}if (values[values.Length - 1].EndsWith("\n")){values[values.Length - 1] = values[values.Length - 1].Substring(0, values[values.Length - 1].LastIndexOf('\n'));}else if (values[values.Length - 1].EndsWith("\n\r")){values[values.Length - 1] = values[values.Length - 1].Substring(0, values[values.Length - 1].LastIndexOf("\n\r", StringComparison.Ordinal));}else if (values[values.Length - 1].EndsWith("\r")){values[values.Length - 1] = values[values.Length - 1].Substring(0, values[values.Length - 1].LastIndexOf('\r'));}return values;}protected virtual void Dispose(bool cleanAll){_iifSet?.Dispose();}public void Dispose(){Dispose(true);GC.SuppressFinalize(this);}

有关dataset的一些常用的操作，基本属性和方法在这里就不做介绍了。