C# Use NPOI operation Excel

1. Introduce namespace

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

2. Read file stream

using (FileStream fs = File.OpenRead(filePath)){}

3. Read EXCEL

3.1 Create workbook object

IWorkbook workbook = null;

3.2 compatible .xls and .xlsx edition

if (filePath.IndexOf(".xlsx") > 0)
{
    workbook = new XSSFWorkbook(fs);
}
//  If it is 2003- Of Excel edition 
else if (filePath.IndexOf(".xls") > 0)
{
	workbook = new HSSFWorkbook(fs);
}

3.3 Get the contents of the form

3.4 Cell related styles

cell.CellType Get cell style , Returns the value

Returns the cell value in the specified form

4. write in Excel

4.1 Create relevant content

4.2 Write the value

cell.SetCellValue(data);

4.3 Output as file

outpath Output path for file

 using (FileStream fs = File.OpenWrite(Outpath))
                {
                    workbook.Write(fs);// To the open one xls Write data to file 
                    result = true;
                }