16

我想使用 NPOI 读取 Excel Tables 2010 xlsx，然后将数据导出到 DataTables 但不知道如何使用它。谁能逐步告诉我如何将 Excel 导出到 Datatable？我已经下载了 NPOI.dll，添加到参考，但不知道还有什么...

4

11 回答 11

20

以下是您可以使用 NPOI 将 Excel 文件转换为 DataSet 的最少代码：

IWorkbook workbook;
using (var stream = new FileStream(excelFilePath, FileMode.Open, FileAccess.Read))
{
    workbook = new HSSFWorkbook(stream); // XSSFWorkbook for XLSX
}

var sheet = workbook.GetSheetAt(0); // zero-based index of your target sheet
var dataTable = new DataTable(sheet.SheetName);

// write the header row
var headerRow = sheet.GetRow(0);
foreach (var headerCell in headerRow)
{
    dataTable.Columns.Add(headerCell.ToString());
}

// write the rest
for(int i = 1; i< sheet.PhysicalNumberOfRows; i++)
{
    var sheetRow = sheet.GetRow(i);
    var dtRow = dataTable.NewRow();
    dtRow.ItemArray = dataTable.Columns
        .Cast<DataColumn>()
        .Select(c => sheetRow.GetCell(c.Ordinal, MissingCellPolicy.CREATE_NULL_AS_BLANK).ToString())
        .ToArray();
    dataTable.Rows.Add(dtRow);
}
于 2015-11-03T08:54:28.847 回答
5 
private static ISheet GetFileStream(string fullFilePath)
{
    var fileExtension = Path.GetExtension(fullFilePath);
    string sheetName;
    ISheet sheet = null;
    switch (fileExtension)
    {
        case ".xlsx":
            using (var fs = new FileStream(fullFilePath, FileMode.Open, FileAccess.Read))
            {
                var wb = new XSSFWorkbook(fs);
                sheetName = wb.GetSheetAt(0).SheetName;
                sheet = (XSSFSheet) wb.GetSheet(sheetName);
            }
            break;
        case ".xls":
            using (var fs = new FileStream(fullFilePath, FileMode.Open, FileAccess.Read))
            {
                var wb = new HSSFWorkbook(fs);
                sheetName = wb.GetSheetAt(0).SheetName;
                sheet = (HSSFSheet) wb.GetSheet(sheetName);
            }
            break;
    }
    return sheet;
}

private static DataTable GetRequestsDataFromExcel(string fullFilePath)
{
    try
    {
        var sh = GetFileStream(fullFilePath);
        var dtExcelTable = new DataTable();
        dtExcelTable.Rows.Clear();
        dtExcelTable.Columns.Clear();
        var headerRow = sh.GetRow(0);
        int colCount = headerRow.LastCellNum;
        for (var c = 0; c < colCount; c++)
            dtExcelTable.Columns.Add(headerRow.GetCell(c).ToString());
        var i = 1;
        var currentRow = sh.GetRow(i);
        while (currentRow != null)
        {
            var dr = dtExcelTable.NewRow();
            for (var j = 0; j < currentRow.Cells.Count; j++)
            {
                var cell = currentRow.GetCell(j);

                if (cell != null)
                    switch (cell.CellType)
                    {
                        case CellType.Numeric:
                            dr[j] = DateUtil.IsCellDateFormatted(cell)
                                ? cell.DateCellValue.ToString(CultureInfo.InvariantCulture)
                                : cell.NumericCellValue.ToString(CultureInfo.InvariantCulture);
                            break;
                        case CellType.String:
                            dr[j] = cell.StringCellValue;
                            break;
                        case CellType.Blank:
                            dr[j] = string.Empty;
                            break;
                    }
            }
            dtExcelTable.Rows.Add(dr);
            i++;
            currentRow = sh.GetRow(i);
        }
        return dtExcelTable;
    }
    catch (Exception e)
    {
        throw;
    }
}
于 2017-07-03T08:03:44.767 回答
4

您可以通过 NPOI 尝试这种简单的方法：

private DataTable GetDataTableFromExcel(String Path)
    {
        XSSFWorkbook wb;
        XSSFSheet sh;
        String Sheet_name;

        using (var fs = new FileStream(Path, FileMode.Open, FileAccess.Read))
        {
            wb = new XSSFWorkbook(fs);

               Sheet_name= wb.GetSheetAt(0).SheetName;  //get first sheet name
        }
        DataTable DT = new DataTable();
        DT.Rows.Clear();
        DT.Columns.Clear();

        // get sheet
        sh = (XSSFSheet)wb.GetSheet(Sheet_name);

        int i = 0;
        while (sh.GetRow(i) != null)
        {
            // add neccessary columns
            if (DT.Columns.Count < sh.GetRow(i).Cells.Count)
            {
                for (int j = 0; j < sh.GetRow(i).Cells.Count; j++)
                {
                    DT.Columns.Add("", typeof(string));
                }
            }

            // add row
            DT.Rows.Add();

            // write row value
            for (int j = 0; j < sh.GetRow(i).Cells.Count; j++)
            {
                var cell = sh.GetRow(i).GetCell(j);

                if (cell != null)
                {
                    // TODO: you can add more cell types capatibility, e. g. formula
                    switch (cell.CellType)
                    {
                        case NPOI.SS.UserModel.CellType.Numeric:
                            DT.Rows[i][j] = sh.GetRow(i).GetCell(j).NumericCellValue;
                            //dataGridView1[j, i].Value = sh.GetRow(i).GetCell(j).NumericCellValue;

                            break;
                        case NPOI.SS.UserModel.CellType.String:
                            DT.Rows[i][j] = sh.GetRow(i).GetCell(j).StringCellValue;

                            break;
                    }
                }
            }

            i++;
        }

        return DT;
    }
于 2015-09-04T09:19:37.643 回答
2

你可以通过这样做来完成你的任务。

using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using NPOI.Util.Collections;
using NPOI;
using System.Collections.Generic;
using NPOI.OpenXmlFormats.Spreadsheet;
using NPOI.HSSF.UserModel;
using NPOI.SS.Util;

public DataTable xlsxToDT(Stream str)
{
XSSFWorkbook hssfworkbook = new XSSFWorkbook(str);
ISheet sheet = hssfworkbook.GetSheetAt(0);
str.Close();

DataTable dt = new DataTable();
IRow headerRow = sheet.GetRow(0);
IEnumerator rows = sheet.GetRowEnumerator();

int colCount = headerRow.LastCellNum;
int rowCount = sheet.LastRowNum;

for (int c = 0; c < colCount; c++)
    dt.Columns.Add(headerRow.GetCell(c).ToString());

while (rows.MoveNext())
{
    IRow row = (XSSFRow)rows.Current;
    DataRow dr = dt.NewRow();

    for (int i = 0; i < colCount; i++)
    {
        ICell cell = row.GetCell(i);

        if (cell != null)
            dr[i] = cell.ToString();
    }
    dt.Rows.Add(dr);
}
return dt;

}

于 2014-09-30T15:14:45.920 回答
2

我编辑了@Saeb Amini 代码以允许空白单元格。

IWorkbook workbook;
using (FileStream stream = new FileStream(excelFilePath, FileMode.Open, FileAccess.Read))
{
    workbook = new HSSFWorkbook(stream);
}

ISheet sheet = workbook.GetSheetAt(0);
DataTable dt = new DataTable(sheet.SheetName);

// write header row
IRow headerRow = sheet.GetRow(0);
foreach (ICell headerCell in headerRow)
{
    dt.Columns.Add(headerCell.ToString());
}

// write the rest
int rowIndex = 0;
foreach (IRow row in sheet)
{
     // skip header row
     if (rowIndex++ == 0) continue;

     // add row into datatable
     var cells = new List<ICell>();
     for (int i = 0; i < dt.Columns.Count; i++)
     {
          cells.Add(row.GetCell(i, MissingCellPolicy.CREATE_NULL_AS_BLANK));
     }

     // Columns formatted as DateTime will be printed as '01-Jul-2005', 
     // which can be converted to datetime in the SQL server.
     // select cast('01-Jul-2005' as DateTime).
     // In SQL Server we can convert DateTime to whatever string we want, for example
     // select convert(nvarchar(255), cast('01-Jul-2005' as datetime), 112) will print '20050701'.
     // http://www.sqlusa.com/bestpractices/datetimeconversion/
     dt.Rows.Add(cells.Select(c => c.ToString()).ToArray());

     // Datetimes also can be reformatted directly like this :
     // dt.Rows.Add(cells.Select(c =>
     //    c.CellType == CellType.Numeric && DateUtil.IsCellDateFormatted(c) 
     //        ? c.DateCellValue.ToString("yyyyMMdd") 
     //        : c.ToString()
     // ).ToArray());

}

//return dt;
于 2018-11-14T12:33:10.990 回答
2

NPOI 是读取 Excel 文件的绝佳且免费的方式，现在在版本 2 中，您可以读取 XLS 和 XLSX 文件类型。

  1. 在他们的网站上获取最新版本的 NPOI： https ://npoi.codeplex.com/
  2. 在您的项目中添加对以下文件的引用：NPOI.dll、NPOI.OOXML.dll 和 NPOI.OpenXml4Net.dll。
  3. 添加以下Usings： using NPOI.SS.UserModel; 使用 NPOI.HSSF.UserModel；使用 NPOI.XSSF.UserModel；

现在下面的代码可以解决问题，注释是西班牙语，抱歉:-p

private DataTable Excel_To_DataTable(string pRutaArchivo, int pHojaIndex)
    {
        // --------------------------------- //
        /* REFERENCIAS:
         * NPOI.dll
         * NPOI.OOXML.dll
         * NPOI.OpenXml4Net.dll */
        // --------------------------------- //
        /* USING:
         * using NPOI.SS.UserModel;
         * using NPOI.HSSF.UserModel;
         * using NPOI.XSSF.UserModel; */
        // --------------------------------- //
        DataTable Tabla = null;
        try
        {
            if (System.IO.File.Exists(pRutaArchivo))
            {

                IWorkbook workbook = null;  //IWorkbook determina se es xls o xlsx              
                ISheet worksheet = null;
                string first_sheet_name = "";

                using (FileStream FS = new FileStream(pRutaArchivo, FileMode.Open, FileAccess.Read))
                {
                    workbook = WorkbookFactory.Create(FS); //Abre tanto XLS como XLSX
                    worksheet = workbook.GetSheetAt(pHojaIndex); //Obtener Hoja por indice
                    first_sheet_name = worksheet.SheetName;  //Obtener el nombre de la Hoja

                    Tabla = new DataTable(first_sheet_name);
                    Tabla.Rows.Clear();
                    Tabla.Columns.Clear();

                    // Leer Fila por fila desde la primera
                    for (int rowIndex = 0; rowIndex <= worksheet.LastRowNum; rowIndex++)
                    {
                        DataRow NewReg = null;
                        IRow row = worksheet.GetRow(rowIndex);
                        IRow row2 = null;

                        if (row != null) //null is when the row only contains empty cells 
                        {
                            if (rowIndex > 0) NewReg = Tabla.NewRow();

                            //Leer cada Columna de la fila
                            foreach (ICell cell in row.Cells)
                            {
                                object valorCell = null;
                                string cellType = "";

                                if (rowIndex == 0) //Asumo que la primera fila contiene los titlos:
                                {
                                    row2 = worksheet.GetRow(rowIndex + 1); //Si es la rimera fila, obtengo tambien la segunda para saber los tipos:
                                    ICell cell2 = row2.GetCell(cell.ColumnIndex);
                                    switch (cell2.CellType)
                                    {
                                        case CellType.Boolean: cellType = "System.Boolean"; break;
                                        case CellType.String: cellType = "System.String"; break;
                                        case CellType.Numeric:
                                            if (HSSFDateUtil.IsCellDateFormatted(cell2)) { cellType = "System.DateTime"; }
                                            else { cellType = "System.Double"; }        break;
                                        case CellType.Formula:
                                            switch (cell2.CachedFormulaResultType)
                                            {
                                                case CellType.Boolean: cellType = "System.Boolean"; break;
                                                case CellType.String: cellType = "System.String"; break;
                                                case CellType.Numeric:
                                                    if (HSSFDateUtil.IsCellDateFormatted(cell2)) { cellType = "System.DateTime"; }
                                                    else { cellType = "System.Double"; }    break;
                                            }
                                            break;
                                        default:
                                            cellType = "System.String"; break;
                                    }

                                    //Agregar los campos de la tabla:
                                    DataColumn codigo = new DataColumn(cell.StringCellValue, System.Type.GetType(cellType));
                                    Tabla.Columns.Add(codigo);
                                }
                                else
                                {
                                    //Las demas filas son registros:
                                    switch (cell.CellType)
                                    {
                                        case CellType.Blank:    valorCell = DBNull.Value; break;
                                        case CellType.Boolean:  valorCell = cell.BooleanCellValue; break;
                                        case CellType.String:   valorCell = cell.StringCellValue; break;
                                        case CellType.Numeric:
                                            if (HSSFDateUtil.IsCellDateFormatted(cell)) { valorCell = cell.DateCellValue; }
                                            else { valorCell = cell.NumericCellValue; } break;
                                        case CellType.Formula:
                                            switch (cell.CachedFormulaResultType)
                                            {
                                                case CellType.Blank:    valorCell = DBNull.Value; break;
                                                case CellType.String:   valorCell = cell.StringCellValue; break;
                                                case CellType.Boolean:  valorCell = cell.BooleanCellValue; break;
                                                case CellType.Numeric:
                                                    if (HSSFDateUtil.IsCellDateFormatted(cell)) { valorCell = cell.DateCellValue; }
                                                    else { valorCell = cell.NumericCellValue; }
                                                    break;
                                            }
                                            break;                                          
                                        default: valorCell = cell.StringCellValue; break;
                                    }
                                    NewReg[cell.ColumnIndex] = valorCell;
                                }
                            }
                        }
                        if (rowIndex > 0) Tabla.Rows.Add(NewReg);
                    }
                    Tabla.AcceptChanges();
                }
            }
            else
            {
                throw new Exception("ERROR 404: El archivo especificado NO existe.");
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
        return Tabla;
    }

上面的代码假设工作表的第一行具有列名。该代码还确定每个单元格的数据类型，并尝试将其转换为 ADO 数据类型。空白单元格将转换为 null。

希望这可以帮助您和其他处于相同情况的人。

于 2015-10-31T13:53:50.767 回答
1

您可以在 Toxy 项目中尝试 ToxySpreadsheet - https://github.com/nissl-lab/toxy。ToxySpreadsheet.ToDataSet() 是你想要的。

于 2014-05-20T04:12:42.330 回答
1

在 Codeplex 网站的下载部分有example package- 一组 C# 示例。试试吧，如果你还没有。

这是最简单的例子——

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;

//.....

private void button1_Click(object sender, EventArgs e)
{
    HSSFWorkbook hssfwb;
    using (FileStream file = new FileStream(@"c:\test.xls", FileMode.Open, FileAccess.Read))
    {
        hssfwb= new HSSFWorkbook(file);
    }

    ISheet sheet = hssfwb.GetSheet("Arkusz1");
    for (int row = 0; row <= sheet.LastRowNum; row++)
    {
        if (sheet.GetRow(row) != null) //null is when the row only contains empty cells 
        {
            MessageBox.Show(string.Format("Row {0} = {1}", row, sheet.GetRow(row).GetCell(0).StringCellValue));
        }
    }
}
于 2012-11-11T17:13:33.253 回答
1

基于@Sean 的 GREAT Answer 和NPOI 示例，我将方法写入Convert all worksheets in xls file to DataSetand Convert DataSet back to xls file：

    public static DataSet GetDataSetFromXls(string excelFilePath)
    {
        IWorkbook workbook;
        using (FileStream stream = new FileStream(excelFilePath, FileMode.Open, FileAccess.Read))
        {
            workbook = new HSSFWorkbook(stream);  //2003 xls
            //workbook = new XSSFWorkbook();  //2007 xlsx
        }

        DataSet ds = new DataSet();
        for (int i = 0; i < workbook.NumberOfSheets; i++)
        {
            ISheet sheet = workbook.GetSheetAt(i); // zero-based index of your target sheet
            DataTable dt = new DataTable(sheet.SheetName);

            // write header row
            IRow headerRow = sheet.GetRow(0);
            foreach (ICell headerCell in headerRow)
            {
                dt.Columns.Add(headerCell.ToString());
            }

            // write the rest
            int rowIndex = 0;
            foreach (IRow row in sheet)
            {
                // skip header row
                if (rowIndex++ == 0) continue;
                DataRow dataRow = dt.NewRow();
                dataRow.ItemArray = row.Cells.Select(c => c.ToString()).ToArray();
                dt.Rows.Add(dataRow);
            }

            ds.Tables.Add(dt);
        }

        return ds;
    }


    public static void SaveDataSetToXls(DataSet ds, string savedExcelFilePath)
    {
        //IWorkbook workbook = new XSSFWorkbook();
        IWorkbook workbook = new HSSFWorkbook();

        foreach (DataTable dt in ds.Tables)
        {
            ISheet sheet = workbook.CreateSheet(dt.TableName);

            var row0 = sheet.CreateRow(0);//header
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                row0.CreateCell(j).SetCellValue(dt.Columns[j].ColumnName);
            }

            for (int i = 0; i < dt.Rows.Count; i++)//rest
            {
                var row = sheet.CreateRow(1+i);
                for (int j = 0; j < dt.Columns.Count; j++)
                    row.CreateCell(j).SetCellValue(dt.Rows[i][j].ToString());
            }
        }

        FileStream sw = File.Create(savedExcelFilePath);
        workbook.Write(sw);
        sw.Close();
    }
于 2018-11-15T16:03:08.740 回答
0

我知道我在这里有点晚了，但我认为这可能对其他人有所帮助

我使用 NPOI 包开发了一个 excel 实用程序，它可以

  1. 只需获取您的数据表或集合
  2. 并返回您的 excel，同时在 excel 中保持所有数据表/列表数据类型不变。

Github 代码仓库：https ://github.com/ansaridawood/.NET-Generic-Excel-Export-Sample/tree/master/GenericExcelExport/ExcelExport

找代码解释，可以在这里找到： https ://www.codeproject.com/Articles/1241654/Export-to-Excel-using-NPOI-Csharp-and-WEB-API

它使用 NPOI DLL 并包含 2 个 cs 文件，然后你就可以开始了

以下是参考AbstractDataExport.cs的第一个文件：

using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;

namespace GenericExcelExport.ExcelExport
{
    public interface IAbstractDataExport
    {
        HttpResponseMessage Export(List exportData, string fileName, string sheetName);
    }

    public abstract class AbstractDataExport : IAbstractDataExport
    {
        protected string _sheetName;
        protected string _fileName;
        protected List _headers;
        protected List _type;
        protected IWorkbook _workbook;
        protected ISheet _sheet;
        private const string DefaultSheetName = "Sheet1";

        public HttpResponseMessage Export
              (List exportData, string fileName, string sheetName = DefaultSheetName)
        {
            _fileName = fileName;
            _sheetName = sheetName;

            _workbook = new XSSFWorkbook(); //Creating New Excel object
            _sheet = _workbook.CreateSheet(_sheetName); //Creating New Excel Sheet object

            var headerStyle = _workbook.CreateCellStyle(); //Formatting
            var headerFont = _workbook.CreateFont();
            headerFont.IsBold = true;
            headerStyle.SetFont(headerFont);

            WriteData(exportData); //your list object to NPOI excel conversion happens here

            //Header
            var header = _sheet.CreateRow(0);
            for (var i = 0; i < _headers.Count; i++)
            {
                var cell = header.CreateCell(i);
                cell.SetCellValue(_headers[i]);
                cell.CellStyle = headerStyle;
            }

            for (var i = 0; i < _headers.Count; i++)
            {
                _sheet.AutoSizeColumn(i);
            }

            using (var memoryStream = new MemoryStream()) //creating memoryStream
            {
                _workbook.Write(memoryStream);
                var response = new HttpResponseMessage(HttpStatusCode.OK)
                {
                    Content = new ByteArrayContent(memoryStream.ToArray())
                };

                response.Content.Headers.ContentType = new MediaTypeHeaderValue
                       ("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
                response.Content.Headers.ContentDisposition = 
                       new ContentDispositionHeaderValue("attachment")
                {
                    FileName = $"{_fileName}_{DateTime.Now.ToString("yyyyMMddHHmmss")}.xlsx"
                };

                return response;
            }
        }

        //Generic Definition to handle all types of List
        public abstract void WriteData(List exportData);
    }
}

这是第二个也是最后一个文件AbstractDataExportBridge.cs：

using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Text.RegularExpressions;

namespace GenericExcelExport.ExcelExport
{
    public class AbstractDataExportBridge : AbstractDataExport
    {
        public AbstractDataExportBridge()
        {
            _headers = new List<string>();
            _type = new List<string>();
        }

        public override void WriteData<T>(List<T> exportData)
        {
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));

            DataTable table = new DataTable();

            foreach (PropertyDescriptor prop in properties)
            {
                var type = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
                _type.Add(type.Name);
                table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? 
                                  prop.PropertyType);
                string name = Regex.Replace(prop.Name, "([A-Z])", " $1").Trim(); //space separated 
                                                                           //name by caps for header
                _headers.Add(name);
            }

            foreach (T item in exportData)
            {
                DataRow row = table.NewRow();
                foreach (PropertyDescriptor prop in properties)
                    row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;
                table.Rows.Add(row);
            }

            IRow sheetRow = null;

            for (int i = 0; i < table.Rows.Count; i++)
            {
                sheetRow = _sheet.CreateRow(i + 1);
                for (int j = 0; j < table.Columns.Count; j++)
                {
                    ICell Row1 = sheetRow.CreateCell(j);

                    string type = _type[j].ToLower();
                    var currentCellValue = table.Rows[i][j];

                    if (currentCellValue != null && 
                        !string.IsNullOrEmpty(Convert.ToString(currentCellValue)))
                    {
                        if (type == "string")
                        {
                            Row1.SetCellValue(Convert.ToString(currentCellValue));
                        }
                        else if (type == "int32")
                        {
                            Row1.SetCellValue(Convert.ToInt32(currentCellValue));
                        }
                        else if (type == "double")
                        {
                            Row1.SetCellValue(Convert.ToDouble(currentCellValue));
                        }
                    }
                    else
                    {
                        Row1.SetCellValue(string.Empty);
                    }
                }
            }
        }
    }
}

有关详细说明，请参阅开头提供的链接。

于 2021-01-15T15:04:53.307 回答
0

您可以将 nuget 包用于 NOPI

读取Excel

基本用法：ExcelImportHelper.ReadExcel(bytes);

于 2020-12-25T16:22:27.600 回答