从字符串 [][] 生成 CSV 文件

本文关键字：文件 CSV 生成 字符串 | 更新日期: 2023-09-27 18:33:30

我有一个MVC控制器，它应该从string[][]返回CSV文件。我正在尝试此示例：

public FileContentResult DownloadCSV()
{
    string[][] output = new string[][]{  
            new string[]{"Col 1 Row 1", "Col 2 Row 1", "Col 3 Row 1"},  
            new string[]{"Col1 Row 2", "Col2 Row 2", "Col3 Row 2"}  
        };
    return File(output, "text/csv", "Report123.csv");
}

但是我不知道如何创建文件。如何从string[][]创建 CSV 文件？

从字符串 [][] 生成 CSV 文件

下面是

使用 LINQ 的示例。

public FileContentResult DownloadCSV()
{
    string[][] output = new string[][]{  
        new string[]{"Col 1 Row 1", "Col 2 Row 1", "Col 3 Row 1"},  
        new string[]{"Col1 Row 2", "Col2 Row 2", "Col3 Row 2"}  
    };
    var result = lines.Select(l=>string.Join(",", l))
                      .Aggregate(new StringBuilder(), (sb, v) => sb.AppendLine(v))
                      .ToString();
    return File(result, "text/csv", "Report123.csv");
}

。作为扩展方法... 

public static class ToolsEx
{
    public static string ToCsvString(this string[][] lines)
    {
        var query = lines.Select(l=>string.Join(",", l));
        var result = query.Aggregate(new StringBuilder(), (sb, v) => sb.AppendLine(v));
        return result.ToString();
    }
}

。在记住string.Join内部使用 StringBuilder 之后，您可以进一步将其减少到（如果其他人要在您之后维护它，这可能会有点多）...... 

public static string ToCsvString(this string[][] rows)
{
    return string.Join(Environment.NewLine, rows.Select(row => string.Join(",", row)));
}

使用扩展方法生成 csv 文件

    /// <summary>
    /// Convert an array to string list, of the form "1,2,3,.."        
    /// </summary>
    /// <param name="array">The array of numbers</param>
    /// <returns>A string value</returns>
    public static string ToCSVRow<T>(this T[] array)
    {
        string[] parts=new string[array.Length];
        for(int i=0; i<parts.Length; i++)
        {
            parts[i]=array[i].ToString();
        }
        return string.Join(",", parts);
    }
    /// <summary>
    /// Convert a jagged array to csv table, where each row has the form "1,2,3,.."
    /// </summary>
    /// <param name="array">The array of numbers</param>
    /// <returns>A string value</returns>
    public static string ToCSV<T>(this T[][] array)
    {
        List<string> csv=new List<string>();
        for(int i=0; i<array.Length; i++)
        {
            csv.Add(array[i].ToCSVRow());
        }
        return string.Join(Environment.NewLine, csv.ToArray());
    }

并用于

return File(output.ToCSV(), "text/csv", "Report123.csv");

编辑 1

根据注释，执行以下操作会更简单，也许更快：

    /// <summary>
    /// Convert an array to a csv row, of the form "1,2,3,4.."
    /// </summary>
    /// <typeparam name="T">The array type</typeparam>
    /// <param name="list">The array</param>
    /// <returns>A comma delimited string</returns>
    public static string ToCSVRow<T>(this T[] list)
    {
        return string.Join(",", list);
    }
    /// <summary>
    /// Convert a jagged array to csv table, where each row has the form "1,2,3,.."
    /// </summary>
    /// <param name="array">The array of numbers</param>
    /// <returns>A string value</returns>
    public static string ToCSV<T>(this T[][] array)
    {
        return string.Join(Environment.NewLine, array.Select((row) => string.Join(",", row)));
    }
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