winform 利用 NPOI导入，导出excel
一，引用npoi
按 工具->NuGet 包管理器->程序包管理控制台 顺序依次点击，在 VS2015 界面的弹出的 程序包管理控制台输入 Install-Package NPOI -Version 2.4.1
二、编写npoi工具类
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data;
using System.Windows.Forms;
using NPOI.SS.UserModel;
using NPOI.HSSF.UserModel;
using NPOI.XSSF.UserModel;
/**
**利用 NPOI导入导出excel
**/
namespace XXX.Util
{
class ExcelHelperForCs
{
#region 私有方法
///
/// 获取要保存的文件名称（含完整路径）
///
///
/// 判断是否为兼容模式
///
///
///
/// 创建工作薄
///
///
///
/// 创建工作薄(依据文件流)
///
///
///
///
/// 创建表格头单元格
///
///
///
/// 从工作表中生成DataTable
///
///
///
///
/// 由DataSet导出Excel
///
/// 要导出数据的DataTable
/// Excel工作表
public static string ExportToExcel(DataSet sourceDs, string filePath = null)
{
if (string.IsNullOrEmpty(filePath))
{
filePath = GetSaveFilePath();
}
if (string.IsNullOrEmpty(filePath)) return null;
bool isCompatible = GetIsCompatible(filePath);
IWorkbook workbook = CreateWorkbook(isCompatible);
ICellStyle cellStyle = GetCellStyle(workbook);
for (int i = 0; i < sourceDs.Tables.Count; i++)
{
DataTable table = sourceDs.Tables[i];
string sheetName = "result" + i.ToString();
ISheet sheet = workbook.CreateSheet(sheetName);
IRow headerRow = sheet.CreateRow(0);
// handling header.
foreach (DataColumn column in table.Columns)
{
ICell cell = headerRow.CreateCell(column.Ordinal);
cell.SetCellValue(column.ColumnName);
cell.CellStyle = cellStyle;
}
// handling value.
int rowIndex = 1;
foreach (DataRow row in table.Rows)
{
IRow dataRow = sheet.CreateRow(rowIndex);
foreach (DataColumn column in table.Columns)
{
dataRow.CreateCell(column.Ordinal).SetCellValue((row[column] ?? "").ToString());
}
rowIndex++;
}
}
FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite);
workbook.Write(fs);
fs.Dispose();
workbook = null;
return filePath;
}
///
/// 由DataTable导出Excel
///
/// 要导出数据的DataTable
/// Excel工作表
public static string ExportToExcel(DataTable sourceTable, string sheetName = "result", string filePath = null)
{
if (sourceTable.Rows.Count <= 0) return null;
if (string.IsNullOrEmpty(filePath))
{
filePath = GetSaveFilePath();
}
if (string.IsNullOrEmpty(filePath)) return null;
bool isCompatible = GetIsCompatible(filePath);
IWorkbook workbook = CreateWorkbook(isCompatible);
ICellStyle cellStyle = GetCellStyle(workbook);
ISheet sheet = workbook.CreateSheet(sheetName);
IRow headerRow = sheet.CreateRow(0);
// handling header.
foreach (DataColumn column in sourceTable.Columns)
{
ICell headerCell = headerRow.CreateCell(column.Ordinal);
headerCell.SetCellValue(column.ColumnName);
headerCell.CellStyle = cellStyle;
}
// handling value.
int rowIndex = 1;
foreach (DataRow row in sourceTable.Rows)
{
IRow dataRow = sheet.CreateRow(rowIndex);
foreach (DataColumn column in sourceTable.Columns)
{
dataRow.CreateCell(column.Ordinal).SetCellValue((row[column] ?? "").ToString());
}
rowIndex++;
}
FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite);
workbook.Write(fs);
fs.Dispose();
sheet = null;
headerRow = null;
workbook = null;
return filePath;
}
///
/// 由List导出Excel
///
/// 类型
/// 在导出的List
/// sheet名称
/// (List data, IList> headerNameList, string sheetName = "result", string filePath = null) where T : class
{
if (data.Count <= 0) return null;
if (string.IsNullOrEmpty(filePath))
{
filePath = GetSaveFilePath();
}
if (string.IsNullOrEmpty(filePath)) return null;
bool isCompatible = GetIsCompatible(filePath);
IWorkbook workbook = CreateWorkbook(isCompatible);
ICellStyle cellStyle = GetCellStyle(workbook);
ISheet sheet = workbook.CreateSheet(sheetName);
IRow headerRow = sheet.CreateRow(0);
for (int i = 0; i < headerNameList.Count; i++)
{
ICell cell = headerRow.CreateCell(i);
cell.SetCellValue(headerNameList[i].Value);
cell.CellStyle = cellStyle;
}
Type t = typeof(T);
int rowIndex = 1;
foreach (T item in data)
{
IRow dataRow = sheet.CreateRow(rowIndex);
for (int n = 0; n < headerNameList.Count; n++)
{
object pValue = t.GetProperty(headerNameList[n].Key).GetValue(item, null);
dataRow.CreateCell(n).SetCellValue((pValue ?? "").ToString());
}
rowIndex++;
}
FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite);
workbook.Write(fs);
fs.Dispose();
sheet = null;
headerRow = null;
workbook = null;
return filePath;
}
///
/// 由DataGridView导出
///
///
///
///
///
/// 由Excel导入DataTable
///
/// Excel文件流
/// Excel工作表名称
/// Excel表头行索引
/// 是否为兼容模式
/// DataTable
public static DataTable ImportFromExcel(Stream excelFileStream, string sheetName, int headerRowIndex, bool isCompatible)
{
IWorkbook workbook = CreateWorkbook(isCompatible, excelFileStream);
ISheet sheet = null;
int sheetIndex = -1;
if (int.TryParse(sheetName, out sheetIndex))
{
sheet = workbook.GetSheetAt(sheetIndex);
}
else
{
sheet = workbook.GetSheet(sheetName);
}
DataTable table = GetDataTableFromSheet(sheet, headerRowIndex);
excelFileStream.Close();
workbook = null;
sheet = null;
return table;
}
///
/// 由Excel导入DataTable
///
/// Excel文件路径，为物理路径。
/// Excel工作表名称
/// Excel表头行索引
/// DataTable
public static DataTable ImportFromExcel(string excelFilePath, string sheetName, int headerRowIndex)
{
using (FileStream stream = System.IO.File.OpenRead(excelFilePath))
{
bool isCompatible = GetIsCompatible(excelFilePath);
return ImportFromExcel(stream, sheetName, headerRowIndex, isCompatible);
}
}
///
/// 由Excel导入DataSet，如果有多个工作表，则导入多个DataTable
///
/// Excel文件流
/// Excel表头行索引
/// 是否为兼容模式
/// DataSet
public static DataSet ImportFromExcel(Stream excelFileStream, int headerRowIndex, bool isCompatible)
{
DataSet ds = new DataSet();
IWorkbook workbook = CreateWorkbook(isCompatible, excelFileStream);
for (int i = 0; i < workbook.NumberOfSheets; i++)
{
ISheet sheet = workbook.GetSheetAt(i);
DataTable table = GetDataTableFromSheet(sheet, headerRowIndex);
ds.Tables.Add(table);
}
excelFileStream.Close();
workbook = null;
return ds;
}
///
/// 由Excel导入DataSet，如果有多个工作表，则导入多个DataTable
///
/// Excel文件路径，为物理路径。
/// Excel表头行索引
/// DataSet
public static DataSet ImportFromExcel(string excelFilePath, int headerRowIndex)
{
using (FileStream stream = System.IO.File.OpenRead(excelFilePath))
{
bool isCompatible = GetIsCompatible(excelFilePath);
return ImportFromExcel(stream, headerRowIndex, isCompatible);
}
}
#endregion
#region 公共转换方法
///
/// 将Excel的列索引转换为列名，列索引从0开始，列名从A开始。如第0列为A，第1列为B...
///
/// 列索引
/// 列名，如第0列为A，第1列为B...
public static string ConvertColumnIndexToColumnName(int index)
{
index = index + 1;
int system = 26;
char[] digArray = new char[100];
int i = 0;
while (index > 0)
{
int mod = index % system;
if (mod == 0) mod = system;
digArray[i++] = (char)(mod - 1 + 'A');
index = (index - 1) / 26;
}
StringBuilder sb = new StringBuilder(i);
for (int j = i - 1; j >= 0; j--)
{
sb.Append(digArray[j]);
}
return sb.ToString();
}
///
/// 转化日期
///
/// 日期
///
/// 转化数字
///
/// 数字字符串
/// 三、使用导出、导入
/**
**导出excel
**/
private void button2_Click(object sender, EventArgs e)
{
ExcelHelperForCs ehf = new ExcelHelperForCs();
ehf.ExportToExcel(dataGridView1, "代码", null);
}
/**
**导入数据
**/
private void button1_Click(object sender, EventArgs e)
{
//打开一个文件选择框
OpenFileDialog ofd = new OpenFileDialog();
ofd.Title = "Excel文件";
ofd.FileName = "";
ofd.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);//为了获取特定的系统文件夹，可以使用System.Environment类的静态方法GetFolderPath()。该方法接受一个Environment.SpecialFolder枚举，其中可以定义要返回路径的哪个系统目录
ofd.Filter = "Excel文件| *.xlsx;*.xls";
ofd.ValidateNames = true; //文件有效性验证ValidateNames，验证用户输入是否是一个有效的Windows文件名
ofd.CheckFileExists = true; //验证路径有效性
ofd.CheckPathExists = true; //验证文件有效性
string strName = string.Empty;
if (ofd.ShowDialog() == DialogResult.OK)
{
strName = ofd.FileName;
}
if (strName == "")
{
MessageBox.Show("没有选择Excel文件！无法进行数据导入");
return;
}
try {
DataTable dt = ExcelHelperForCs.ImportFromExcel(strName, "合金代码", 0);
this.dataGridView1.dataSource = dt.defaultView;
MessageBox.Show("导入成功！");
}
catch () {
MessageBox.Show("导入失败！");
}
}