CSVファイルを配列に格納する方法

CSVファイルを配列に格納する方法
VB.NET

Public Shared Function CsvToArrayList1(ByVal csvText As String) _
    As System.Collections.ArrayList
    Dim csvRecords As New System.Collections.ArrayList

    csvText = csvText.Trim( _
        New Char() {ControlChars.Cr, ControlChars.Lf})

    Dim regLine As New System.Text.RegularExpressions.Regex( _
        "^.*(?:\n|$)", _
        System.Text.RegularExpressions.RegexOptions.Multiline)

    Dim regCsv As New System.Text.RegularExpressions.Regex( _
        "\s*(""(?:[^""]|"""")*""|[^,]*)\s*,", _
        System.Text.RegularExpressions.RegexOptions.None)

    Dim mLine As System.Text.RegularExpressions.Match = _
        regLine.Match(csvText)
    While mLine.Success
        Dim line As String = mLine.Value
        While CountString(line, """") Mod 2 = 1
            mLine = mLine.NextMatch()
            If Not mLine.Success Then
                Throw New ApplicationException("不正なCSV")
            End If
            line += mLine.Value
        End While
        line = line.TrimEnd( _
            New Char() {ControlChars.Cr, ControlChars.Lf})
        line += ","

        Dim csvFields As New System.Collections.ArrayList
        Dim m As System.Text.RegularExpressions.Match = _
            regCsv.Match(line)
        While m.Success
            Dim field As String = m.Groups(1).Value
            field = field.Trim()
            If field.StartsWith("""") And field.EndsWith("""") Then
                field = field.Substring(1, field.Length - 2)
                field = field.Replace("""""", """")
            End If
            csvFields.Add(field)
            m = m.NextMatch()
        End While

        csvFields.TrimToSize()
        csvRecords.Add(csvFields)

        mLine = mLine.NextMatch()
    End While

    csvRecords.TrimToSize()
    Return csvRecords
End Function

Public Shared Function CountString( _
    ByVal strInput As String, _
    ByVal strFind As String) As Integer
    Dim foundCount As Integer = 0
    Dim sPos As Integer = strInput.IndexOf(strFind)
    While sPos > -1
        foundCount += 1
        sPos = strInput.IndexOf(strFind, sPos + 1)
    End While

    Return foundCount
End Function

C#

public static System.Collections.ArrayList CsvToArrayList1(string csvText)
{
    System.Collections.ArrayList csvRecords =
        new System.Collections.ArrayList();

    csvText = csvText.Trim(new char[] {'\r', '\n'});

    System.Text.RegularExpressions.Regex regLine =
        new System.Text.RegularExpressions.Regex(
        "^.*(?:\\n|$)",
        System.Text.RegularExpressions.RegexOptions.Multiline);

    System.Text.RegularExpressions.Regex regCsv =
        new System.Text.RegularExpressions.Regex(
        "\\s*(\"(?:[^\"]|\"\")*\"|[^,]*)\\s*,",
        System.Text.RegularExpressions.RegexOptions.None);

    System.Text.RegularExpressions.Match mLine = regLine.Match(csvText);
    while (mLine.Success)
    {
        string line = mLine.Value;
        while ((CountString(line, "\"") % 2) == 1)
        {
            mLine = mLine.NextMatch();
            if (!mLine.Success)
            {
                throw new ApplicationException("不正なCSV");
            }
            line += mLine.Value;
        }
        line = line.TrimEnd(new char[] {'\r', '\n'});
        line += ",";

        System.Collections.ArrayList csvFields =
            new System.Collections.ArrayList();
        System.Text.RegularExpressions.Match m = regCsv.Match(line);
        while (m.Success)
        {
            string field = m.Groups[1].Value;
            field = field.Trim();
            if (field.StartsWith("\"") && field.EndsWith("\""))
            {
                field = field.Substring(1, field.Length - 2);
                field = field.Replace("\"\"", "\"");
            }
            csvFields.Add(field);
            m = m.NextMatch();
        }

        csvFields.TrimToSize();
        csvRecords.Add(csvFields);

        mLine = mLine.NextMatch();
    }

    csvRecords.TrimToSize();
    return csvRecords;
}

public static int CountString(string strInput, string strFind)
{
    int foundCount = 0;
    int sPos = strInput.IndexOf(strFind);
    while (sPos > -1)
    {
        foundCount++;
        sPos = strInput.IndexOf(strFind, sPos + 1);
    }

    return foundCount;
}

CSVファイルの文字列を解析して配列に格納する方法
VB.NET

Public Shared Function CsvToArrayList2(ByVal csvText As String) _
    As System.Collections.ArrayList
    csvText = csvText.Trim( _
        New Char() {ControlChars.Cr, ControlChars.Lf})

    Dim csvRecords As New System.Collections.ArrayList
    Dim csvFields As New System.Collections.ArrayList

    Dim csvTextLength As Integer = csvText.Length
    Dim startPos As Integer = 0
    Dim endPos As Integer = 0
    Dim field As String = ""

    While True
        While startPos < csvTextLength _
            AndAlso (csvText.Chars(startPos) = " "c _
            OrElse csvText.Chars(startPos) = ControlChars.Tab)
            startPos += 1
        End While

        If startPos < csvTextLength _
            AndAlso csvText.Chars(startPos) = ControlChars.Quote Then
            endPos = startPos
            While True
                endPos = csvText.IndexOf(ControlChars.Quote, endPos + 1)
                If endPos < 0 Then
                    Throw New ApplicationException("""が不正")
                End If
                If endPos + 1 = csvTextLength OrElse _
                    csvText.Chars((endPos + 1)) <> ControlChars.Quote Then
                    Exit While
                End If
                endPos += 1
            End While

            field = csvText.Substring(startPos, endPos - startPos + 1)
            field = field.Substring(1, field.Length - 2). _
                Replace("""""", """")

            endPos += 1
            While endPos < csvTextLength AndAlso _
                csvText.Chars(endPos) <> ","c AndAlso _
                csvText.Chars(endPos) <> ControlChars.Lf
                endPos += 1
            End While
        Else
            endPos = startPos
            While endPos < csvTextLength AndAlso _
                csvText.Chars(endPos) <> ","c AndAlso _
                csvText.Chars(endPos) <> ControlChars.Lf
                endPos += 1
            End While

            field = csvText.Substring(startPos, endPos - startPos)
            field = field.TrimEnd()
        End If

        csvFields.Add(field)

        If endPos >= csvTextLength OrElse _
            csvText.Chars(endPos) = ControlChars.Lf Then
            csvFields.TrimToSize()
            csvRecords.Add(csvFields)
            csvFields = New System.Collections.ArrayList( _
                csvFields.Count)

            If endPos >= csvTextLength Then
                Exit While
            End If
        End If

        startPos = endPos + 1
    End While

    csvRecords.TrimToSize()
    Return csvRecords
End Function

C#

public static System.Collections.ArrayList CsvToArrayList2(string csvText)
{
    csvText = csvText.Trim(new char[] {'\r', '\n'});

    System.Collections.ArrayList csvRecords =
        new System.Collections.ArrayList();
    System.Collections.ArrayList csvFields =
        new System.Collections.ArrayList();

    int csvTextLength = csvText.Length;
    int startPos = 0, endPos = 0;
    string field = "";

    while (true)
    {
        while (startPos < csvTextLength &&
            (csvText[startPos] == ' ' || csvText[startPos] == '\t'))
        {
            startPos++;
        }

        if (startPos < csvTextLength && csvText[startPos] == '"')
        {
            endPos = startPos;
            while (true)
            {
                endPos = csvText.IndexOf('"', endPos + 1);
                if (endPos < 0)
                {
                    throw new ApplicationException("\"が不正");
                }
                if (endPos + 1 == csvTextLength || csvText[endPos + 1] != '"')
                {
                    break;
                }
                endPos++;
            }

            field = csvText.Substring(startPos, endPos - startPos + 1);
            field = field.Substring(1, field.Length - 2).Replace("\"\"", "\"");

            endPos++;
            while (endPos < csvTextLength &&
                csvText[endPos] != ',' && csvText[endPos] != '\n')
            {
                endPos++;
            }
        }
        else
        {
            endPos = startPos;
            while (endPos < csvTextLength &&
                csvText[endPos] != ',' && csvText[endPos] != '\n')
            {
                endPos++;
            }

            field = csvText.Substring(startPos, endPos - startPos);
            field = field.TrimEnd();
        }

        csvFields.Add(field);

        if (endPos >= csvTextLength || csvText[endPos] == '\n')
        {
            csvFields.TrimToSize();
            csvRecords.Add(csvFields);
            csvFields = new System.Collections.ArrayList(
                csvFields.Count);

            if (endPos >= csvTextLength)
            {
                break;
            }
        }

        startPos = endPos + 1;
    }

    csvRecords.TrimToSize();
    return csvRecords;
}

TextFieldParserでCSVファイルを解析する方法
VB.NET

Dim csvRecords As New System.Collections.ArrayList()

Dim csvFileName As String = "C:\create.csv"

Dim tfp As New FileIO.TextFieldParser(csvFileName, _
    System.Text.Encoding.GetEncoding(932))
tfp.TextFieldType = FileIO.FieldType.Delimited
tfp.Delimiters = New String() {","}
tfp.HasFieldsEnclosedInQuotes = True
tfp.TrimWhiteSpace = True

While Not tfp.EndOfData
    Dim fields As String() = tfp.ReadFields()
    csvRecords.Add(fields)
End While

tfp.Close()

C#

System.Collections.ArrayList csvRecords =
    new System.Collections.ArrayList();

string csvFileName = "C:\\new.csv";

Microsoft.VisualBasic.FileIO.TextFieldParser tfp =
    new Microsoft.VisualBasic.FileIO.TextFieldParser(
        csvFileName,
        System.Text.Encoding.GetEncoding(932));
tfp.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited;
tfp.Delimiters = new string[] { "," };
tfp.HasFieldsEnclosedInQuotes = true;
tfp.TrimWhiteSpace = true;

while (!tfp.EndOfData)
{
    string[] fields = tfp.ReadFields();
    csvRecords.Add(fields);
}

tfp.Close();