使用NPOI导入导出Excel(xls/xlsx)数据到DataTable中

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using NPOI.SS.UserModel; //NPOI
using NPOI.HSSF.Util; //NPOI
using NPOI.HSSF.UserModel; //NPOI
using NPOI.XSSF.UserModel; //NPOI
using System.Data.SqlClient;
using System.Data;

/// <summary>
/// Excel某sheet中内容导入到DataTable中
/// 区分xsl和xslx分别处理
/// </summary>
/// <param name="filePath">Excel文件路径,含文件全名</param>
/// <param name="sheetName">此Excel中sheet名</param>
/// <returns></returns>
public DataTable ExcelSheetImportToDataTable(string filePath, string sheetName)
{ DataTable dt = new DataTable(); if (Path.GetExtension(filePath).ToLower() == ".xls".ToLower())
{//.xls
#region .xls文件处理:HSSFWorkbook
try
{
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{ hssfworkbook = new HSSFWorkbook(file);
}
}
catch (Exception e)
{
throw e;
} ISheet sheet = hssfworkbook.GetSheet(sheetName);
System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
HSSFRow headerRow = (HSSFRow)sheet.GetRow(0); //一行最后一个方格的编号 即总的列数
for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
{
//SET EVERY COLUMN NAME
HSSFCell cell = (HSSFCell)headerRow.GetCell(j); dt.Columns.Add(cell.ToString());
} while (rows.MoveNext())
{
IRow row = (HSSFRow)rows.Current;
DataRow dr = dt.NewRow(); if (row.RowNum == 0) continue;//The firt row is title,no need import for (int i = 0; i < row.LastCellNum; i++)
{
if (i>=dt.Columns.Count)//cell count>column count,then break //每条记录的单元格数量不能大于表格栏位数量 20140213
{
break;
} ICell cell = row.GetCell(i); if ((i==0)&&(string.IsNullOrEmpty(cell.ToString())==true))//每行第一个cell为空,break
{
break;
} if (cell == null)
{
dr[i] = null;
}
else
{
dr[i] = cell.ToString();
}
} dt.Rows.Add(dr);
}
#endregion
}
else
{//.xlsx
#region .xlsx文件处理:XSSFWorkbook
try
{
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{ hssfworkbook = new XSSFWorkbook(file);
}
}
catch (Exception e)
{
throw e;
} ISheet sheet = hssfworkbook.GetSheet(sheetName);
System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
XSSFRow headerRow = (XSSFRow)sheet.GetRow(0); //一行最后一个方格的编号 即总的列数
for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
{
//SET EVERY COLUMN NAME
XSSFCell cell = (XSSFCell)headerRow.GetCell(j); dt.Columns.Add(cell.ToString()); } while (rows.MoveNext())
{
IRow row = (XSSFRow)rows.Current;
DataRow dr = dt.NewRow(); if (row.RowNum == 0) continue;//The firt row is title,no need import for (int i = 0; i < row.LastCellNum; i++)
{
if (i >= dt.Columns.Count)//cell count>column count,then break //每条记录的单元格数量不能大于表格栏位数量 20140213
{
break;
} ICell cell = row.GetCell(i); if ((i == 0) && (string.IsNullOrEmpty(cell.ToString()) == true))//每行第一个cell为空,break
{
break;
} if (cell == null)
{
dr[i] = null;
}
else
{
dr[i] = cell.ToString();
}
}
dt.Rows.Add(dr);
}
#endregion
}
return dt;
}

/// <summary>
/// NPOI导出Excel，不依赖本地是否装有Excel，导出速度快
/// </summary>
/// <param name="dataGridView1">要导出的dataGridView控件</param>
/// <param name="sheetName">sheet表名</param>
///
public static void ExportToExcel(DataGridView dataGridView1, string sheetName)
{
SaveFileDialog fileDialog = new SaveFileDialog();
fileDialog.Filter = "Excel(97-2003)|*.xls";
if (fileDialog.ShowDialog() == System.Windows.Forms.DialogResult.Cancel)
{
return;
}
//不允许dataGridView显示添加行，负责导出时会报最后一行未实例化错误
dataGridView1.AllowUserToAddRows = false;
HSSFWorkbook workbook = new HSSFWorkbook();
ISheet sheet = workbook.CreateSheet(sheetName);
IRow rowHead = sheet.CreateRow(0); //填写表头
for (int i = 0; i < dataGridView1.Columns.Count; i++)
{
rowHead.CreateCell(i, CellType.String).SetCellValue(dataGridView1.Columns[i].HeaderText.ToString());
}
//填写内容
for (int i = 0; i < dataGridView1.Rows.Count; i++)
{
IRow row = sheet.CreateRow(i + 1);
for (int j = 0; j < dataGridView1.Columns.Count; j++)
{
row.CreateCell(j, CellType.String).SetCellValue(dataGridView1.Rows[i].Cells[j].Value.ToString());
}
} using (FileStream stream = File.OpenWrite(fileDialog.FileName))
{
workbook.Write(stream);
stream.Close();
}
MessageBox.Show("导出数据成功!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
GC.Collect();
}