C#NPOI.Excel将EXCEL数据转换到dataGridView中

可以使用C#中的NPOI库和DataGridView控件来将Excel数据转换并显示在DataGridView中。下面是一个示例代码：

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System.Data;
using System.Windows.Forms;

public static class ExcelUtility
{
    public static void ExcelToDataGridView(string filePath, DataGridView dataGridView)
    {
        IWorkbook workbook = null;
        ISheet sheet = null;
        DataTable data = new DataTable();

        using (var file = new System.IO.FileStream(filePath, System.IO.FileMode.Open, System.IO.FileAccess.Read))
        {
            if (filePath.EndsWith(".xls"))
            {
                workbook = new HSSFWorkbook(file);
            }
            else if (filePath.EndsWith(".xlsx"))
            {
                workbook = new XSSFWorkbook(file);
            }

            if (workbook != null)
            {
                sheet = workbook.GetSheetAt(0);
                if (sheet != null)
                {
                    var firstRow = sheet.GetRow(0);
                    int cellCount = firstRow.LastCellNum;

                    for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                    {
                        var cell = firstRow.GetCell(i);
                        if (cell != null)
                        {
                            string columnName = cell.ToString();
                            if (!string.IsNullOrEmpty(columnName))
                            {
                                data.Columns.Add(columnName);
                            }
                        }
                    }

                    for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; ++i)
                    {
                        var row = sheet.GetRow(i);
                        if (row != null)
                        {
                            bool emptyRow = true;
                            DataRow dataRow = data.NewRow();
                            for (int j = row.FirstCellNum; j < cellCount; ++j)
                            {
                                if (row.GetCell(j) != null)
                                {
                                    dataRow[j] = row.GetCell(j).ToString();
                                    if (!string.IsNullOrEmpty(dataRow[j].ToString()))
                                    {
                                        emptyRow = false;
                                    }
                                }
                            }

                            if (!emptyRow)
                            {
                                data.Rows.Add(dataRow);
                            }
                        }
                    }
                }
            }
        }

        dataGridView.DataSource = data;
    }
}

这段代码会根据文件路径读取Excel文件，将第一个工作表转换为一个DataTable对象，并将该对象作为DataGridView控件的DataSource来显示Excel数据。你只需要将DataGridView控件添加到窗体中即可。