.NET中如何将文本文件的内容存储到DataSet

  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);
  }