C# DataTable 生成Excel 和 CSV文件

EXCEL

using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System.Data;
using System.IO;

public class ExcelService
{
    public string GenerateExcelFileAndReturnPath(DataTable dataTable)
    {
        IWorkbook workbook = new XSSFWorkbook();
        ISheet sheet = workbook.CreateSheet("Sheet1");

        // 写入列名
        IRow headerRow = sheet.CreateRow(0);
        foreach (DataColumn column in dataTable.Columns)
        {
            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
        }

        // 写入数据
        int rowIndex = 1;
        foreach (DataRow row in dataTable.Rows)
        {
            IRow dataRow = sheet.CreateRow(rowIndex);
            foreach (DataColumn column in dataTable.Columns)
            {
                dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
            }
            rowIndex++;
        }

        // 保存到服务器指定路径
        string filePath = "path/to/save/file.xlsx";
        using (FileStream fileStream = new FileStream(filePath, FileMode.Create))
        {
            workbook.Write(fileStream);
        }

        return filePath; // 返回文件路径
    }
}

生成CSV文件

using System.Data;
using System.IO;
using System.Text;

public class CsvService
{
    public string GenerateCsvFileAndReturnPath(DataTable dataTable)
    {
        StringBuilder sb = new StringBuilder();

        // 写入列名
        foreach (DataColumn column in dataTable.Columns)
        {
            sb.Append(column.ColumnName + ",");
        }
        sb.AppendLine();

        // 写入数据
        foreach (DataRow row in dataTable.Rows)
        {
            foreach (DataColumn column in dataTable.Columns)
            {
                sb.Append(row[column].ToString() + ",");
            }
            sb.AppendLine();
        }

        // 保存到服务器指定路径
        string filePath = "path/to/save/file.csv";
        File.WriteAllText(filePath, sb.ToString());

        return filePath; // 返回文件路径
    }
}