简单的 csv 阅读器？

Question

总而言之，

我一开始就认为这是一项非常简单的任务。 （将 csv 转换为“wiki”格式）但我遇到了一些障碍，我无法解决

我有 3 个主要问题

1）一些单元格包含 \r\n （所以当逐行读取时，这会处理每个新行作为一个新单元格

2）某些行包含“，”（我尝试切换到 \t 删除文件，但当它在两个“”之间时我仍然遇到转义问题）

3）除了分隔符之外，有些行完全空白（ “，”或“\t”）其他不完整（这很好，我只需要确保单元格位于正确的位置）

我已经尝试了一些 CSV 阅读器类，但它们会增加代理上面列出的问题

我试图让这个应用程序尽可能小，所以我也试图避免 dll 和大型类，只有一小部分做我想要的事情。

到目前为止，我有两次“不起作用的尝试

尝试1（不处理单元格中的\r\n）

OpenFileDialog openFileDialog1 = new OpenFileDialog();

            openFileDialog1.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
            openFileDialog1.Filter = "tab sep file (*.txt)|*.txt|All files (*.*)|*.*";
            openFileDialog1.FilterIndex = 1;
            openFileDialog1.RestoreDirectory = true;

            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if (cb_sortable.Checked)
                {
                    header = "{| class=\"wikitable sortable\" border=\"1\" \r\n|+ Sortable table";
                }

                StringBuilder sb = new StringBuilder();
                string line;
                bool firstline = true;
                StreamReader sr = new StreamReader(openFileDialog1.FileName);

                sb.AppendLine(header);

                while ((line = sr.ReadLine()) != null)
                {

                    if (line.Replace("\t", "").Length > 1)
                    {
                        string[] hold;
                        string lead = "| ";

                        if (firstline && cb_header.Checked == true)
                        {
                            lead = "| align=\"center\" style=\"background:#f0f0f0;\"| ";
                        }

                        hold = line.Split('\t');
                        sb.AppendLine(table);
                        foreach (string row in hold)
                        {
                            sb.AppendLine(lead + row.Replace("\"", ""));
                        }


                        firstline = false;
                    }
                }
                sb.AppendLine(footer);
                Clipboard.SetText(sb.ToString());
                MessageBox.Show("Done!");
        }


        }
        string header = "{| class=\"wikitable\" border=\"1\" ";
        string footer = "|}";
        string table = "|-";

尝试2（可以处理\r\n但将单元格移到空白单元格上）（尚未完成）

OpenFileDialog openFileDialog1 = new OpenFileDialog();

        openFileDialog1.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
        openFileDialog1.Filter = "txt file (*.txt)|*.txt|All files (*.*)|*.*";
        openFileDialog1.FilterIndex = 1;
        openFileDialog1.RestoreDirectory = true;

        if (openFileDialog1.ShowDialog() == DialogResult.OK)
        {
            if (cb_sortable.Checked)
            {
                header = "{| class=\"wikitable sortable\" border=\"1\" \r\n|+ Sortable table";
            }


            using (StreamReader sr = new StreamReader(openFileDialog1.FileName))
            {


                string text = sr.ReadToEnd();
                string[] cells = text.Split('\t');
                int columnCount = 0;
                foreach (string cell in cells)
                {

                    if (cell.Contains("\r\n"))
                    {
                        break;
                    }
                    columnCount++;
                }          


            }

基本上我需要的是“如果不是在 \” 之间分割，但我现在不知所措，

任何提示或技巧将不胜感激

Answer 1

查看此项目而不是滚动您自己的 CSV 解析器。

Answer 2

您也可以看看http://www.filehelpers.com/...

不要'如果可以使用库，就不要尝试自己做！

Answer 3

尝试查看此处。您的代码不会发出 Web 请求，但这实际上向您展示了如何解析从 Web 服务返回的 csv。

Answer 4

这里有一个不错的实现...

• Sébastien Lorion 的快速 CSV 阅读器

在这种情况下，使用经过尝试和测试的代码比尝试编写自己的代码更有意义。

Answer 5

对于基本上有两页长的规范来说，CSV 格式具有欺骗性在于它的简单性。互联网上可以找到的大多数短解析器实现在某种程度上都是明显不正确的。尽管如此，该格式似乎几乎不需要 1k+ SLOC 实现。

public static class CsvImport {
    /// <summary>
    /// Parse a Comma Separated Value (CSV) source into rows of strings. [1]
    /// 
    /// The header row (if present) is not treated specially. No checking is
    /// performed to ensure uniform column lengths among rows. If no input
    /// is available, a single row containing String.Empty is returned. No
    /// support is provided for debugging invalid CSV files. Callers who
    /// desire such assistance are encouraged to use a TextReader that can
    /// report the current line and column position.
    /// 
    /// [1] https://www.rfc-editor.org/rfc/rfc4180
    /// </summary>
    public static IEnumerable<string[]> Deserialize(TextReader input) {
        if (input.Peek() == Sentinel) yield return new [] { String.Empty };
        while (input.Peek() != Sentinel) {
            // must read in entire row *now* to see if we're at end of input
            yield return DeserializeRow(input).ToArray(); 
        }
    }

    const int Sentinel = -1;
    const char Quote = '"';
    const char Separator = (char)System.Globalization.CultureInfo.CurrentCulture.TextInfo.ListSeparator;

    static IEnumerable<string> DeserializeRow(TextReader input) {
        var field = new StringBuilder();
        while (true) {
            var c = input.Read();
            if (c == Separator) {
                yield return field.ToString();
                field = new StringBuilder();
            } else if (c == '\r') {
                if (input.Peek() == '\n') {
                    input.Read();
                }
                yield return field.ToString();
                yield break;
            } else if (new [] { '\n', Sentinel }.Contains(c)) {
                yield return field.ToString();
                yield break;
            } else if (c == Quote) {
                field.Append(DeserializeQuoted(input));
            } else {
                field.Append((char) c);
            }
        }
    }

    static string DeserializeQuoted(TextReader input) {
        var quoted = new StringBuilder();
        while (input.Peek() != Sentinel) {
            var c = input.Read();
            if (c == Quote) {
                if (input.Peek() == Quote) {
                    quoted.Append(Quote);
                    input.Read();
                } else {
                    return quoted.ToString();
                }
            } else {
                quoted.Append((char) c);
            }
        }
        throw new UnexpectedEof("End-of-file inside quoted section.");
    }

    public class UnexpectedEof : Exception {
        public UnexpectedEof(string message) : base(message) { }
    }
}