C#操作NPOI实现Excel数据导入导出
首先在项目中引用NPOI,通过管理NuGet程序包，搜索NPOI，选择版本2.3.0（支持.net Framework 4.0）根据自己项目选择适当版本。
1.NpoiExcelHelper.cs Npoi操作Excel类
using System.Data;
using System.io;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using NPOI.HSSF.UserModel;
/// <summary>
/// Npoi操作Excel类
/// </summary>
public static class NpoiExcelHelper
{
/// <summary>
/// 根据Excel文件类型返回IWorkbook
/// </summary>
/// <param name="fileName">文件路径/文件名称（含后缀名）</param>
/// <param name="rowNum">Excel行数</param>
/// <param name="colNum">Excel列数</param>
/// <param name="isFirstRowColumn">第一行是否是标题</param>
/// <returns></returns>
public static IWorkbook GetWorkbook(string fileName, out int rowNum, out int colNum, bool isFirstRowColumn = true)
{
bool isXlsx = Path.GetExtension(fileName).Equals(".xlsx");
if (isXlsx)
{
if (isFirstRowColumn)
{
rowNum = 1048575;
}
else
{
rowNum = 1048576;
}
colNum = 16384;
}
else
{
if (isFirstRowColumn)
{
rowNum = 65535;
}
else
{
rowNum = 65536;
}
colNum = 256;
}
if (File.Exists(fileName))
{
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
if (isXlsx)
{
return new XSSFWorkbook(fs);
}
else
{
return new HSSFWorkbook(fs);
}
}
}
else
{
if (isXlsx)
{
return new XSSFWorkbook();
}
else
{
return new HSSFWorkbook();
}
}
}
/// <summary>
/// 将DataTable中的数据导入到excel中(第一行是标题)
/// 支持根据Excel数据自动分页（多个Sheet）
/// </summary>
/// <param name="dt">DataTable</param>
/// <param name="fileName">文件路径/文件名称（含后缀名）</param>
/// <param name="columnFieldText">字段对应中文 顺序需要跟Excel中数据顺序一致</param>
/// <param name="sheetName">Excel中Sheet名称（多个sheet时 名字后面自动加上数字序号）</param>
/// <returns></returns>
public static byte[] DataTableToExcel(DataTable dt, string fileName, string[,] columnFieldText = null, string sheetName = null)
{
int rowNum = 0;
int colNum = 0;
IWorkbook workbook = GetWorkbook(fileName, out rowNum, out colNum);
var recordNum = dt.Rows.Count;
int totalPage = recordNum % rowNum == 0 ? recordNum / rowNum : recordNum / rowNum + 1;
for (var p = 0; p < totalPage; p++)
{
if (string.IsNullOrEmpty(sheetName))
{
sheetName = dt.TableName;
}
if (totalPage > 1)
{
if (string.IsNullOrEmpty(sheetName))
{
sheetName = "Sheet";
}
sheetName = sheetName + (p + 1).ToString();
}
else
{
if (string.IsNullOrEmpty(sheetName))
{
sheetName = "Sheet1";
}
}
ISheet sheet = workbook.CreateSheet(sheetName);//创建工作表
#region 标题
IRow row = sheet.CreateRow(0);//在工作表中添加一行
if (columnFieldText != null)
{
var dataColumn = columnFieldText.GetLength(0);
if (dataColumn <= colNum)
{
for (int m = 0; m < dataColumn; m++)
{
ICell cell = row.CreateCell(m);//在行中添加一列
cell.SetCellValue(columnFieldText[m, 1]);//设置列的内容
}
}
else
{
//数据列数超过了Excel的列数
}
}
else
{
var dataColumn = dt.Columns.Count;
if (dataColumn <= colNum)
{
for (int i = 0; i < dataColumn; i++)
{
ICell cell = row.CreateCell(i);//在行中添加一列
cell.SetCellValue(dt.Columns[i].ColumnName);//设置列的内容
}
}
else
{
//数据列数超过了Excel的列数
}
}
#endregion
#region 填充数据
int startIndex = p * rowNum;
int endindex = (p + 1) * rowNum - 1;
if (endindex >= recordNum)
{
endindex = recordNum - 1;
}
for (int i = startIndex; i <= endindex; i++)//遍历DataTable行
{
DataRow dataRow = dt.Rows[i];
row = sheet.CreateRow(i - startIndex + 1);//在工作表中添加一行
if (columnFieldText != null)
{
var dataColumn = columnFieldText.GetLength(0);
if (dataColumn <= colNum)
{
for (int m = 0; m < dataColumn; m++)
{
ICell cell = row.CreateCell(m);//在行中添加一列
cell.SetCellValue(dataRow[columnFieldText[m, 0]].ToString());//设置列的内容
}
}
else
{
//数据列数超过了Excel的列数
}
}
else
{
var dataColumn = dt.Columns.Count;
if (dataColumn <= colNum)
{
for (int j = 0; j < dt.Columns.Count; j++)//遍历DataTable列
{
ICell cell = row.CreateCell(j);//在行中添加一列
cell.SetCellValue(dataRow[j].ToString());//设置列的内容
}
}
else
{
//数据列数超过了Excel的列数
}
}
}
#endregion
}
#region 输出Excel
using (MemoryStream stream = new MemoryStream())
{
workbook.Write(stream);
return stream.ToArray();
}
#endregion
}
/// <summary>
/// 将excel中的数据导入到DataTable中(第一行是标题)
/// 支持多个sheet数据导入（建议多个sheet的数据格式保持一致，将没有数据的sheet删除）
/// </summary>
/// <param name="fileName">文件路径（含文件名称后缀名）</param>
/// <param name="columnFieldText">字段对应中文 顺序需要跟Excel中数据顺序一致</param>
/// <param name="sheetName">指定Excel中Sheet名称 如果为null时，读取所有sheet中的数据</param>
/// <returns>返回的DataTable</returns>
public static DataTable ExcelToDataTable(string fileName, string[,] columnFieldText = null, string sheetName = null)
{
DataTable data = new DataTable();
int rowNum = 0;
int colNum = 0;
IWorkbook workbook = GetWorkbook(fileName, out rowNum, out colNum);
for (int e = 0; e < workbook.NumberOfSheets; e++)
{
ISheet sheet = workbook.GetSheetAt(e);
if (sheet != null)
{
var currentSheetIndex = 0;
if (!string.IsNullOrEmpty(sheetName))
{
if (sheet.SheetName == sheetName)
{
currentSheetIndex = e;
}
}
IRow firstRow = sheet.GetRow(0);
if (firstRow != null)
{
int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数
var dataColumn = columnFieldText != null ? columnFieldText.GetLength(0) : cellCount;
int startRow = sheet.FirstRowNum;
if (dataColumn <= colNum)
{
if (e == currentSheetIndex)
{
for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
{
ICell cell = firstRow.GetCell(i);
if (cell != null)
{
string cellValue = cell.StrinGCellValue;
if (cellValue != null)
{
DataColumn column = new DataColumn((columnFieldText != null ? columnFieldText[i, 0] : cellValue));
data.Columns.Add(column);
}
}
}
}
startRow = sheet.FirstRowNum + 1;
//最后一列的标号
int rowCount = sheet.LastRowNum;
for (int i = startRow; i <= rowCount; ++i)
{
IRow row = sheet.GetRow(i);
if (row == null) continue; //没有数据的行默认是null
DataRow dataRow = data.NewRow();
for (int j = row.FirstCellNum; j < cellCount; ++j)
{
if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null
dataRow[j] = row.GetCell(j).ToString();
}
data.Rows.Add(dataRow);
}
}
else
{
//数据列数超过了Excel的列数
}
}
if (!string.IsNullOrEmpty(sheetName))
{
if (sheet.SheetName == sheetName)
{
break;
}
}
}
}
return data;
}
}2.WEB项目的调用方法
（1）数据导出到Excel中（支持根据DataTable数据及Excel自动分成多个Sheet）
调用方法：
int record = 500;
DataTable data = CreateDataTable(record);
string fileName = "客户明细_" + DateTime.Now.ToString("MMddhhmmss") + ".xls";
string sheetName = "客户明细";
string[,] columnFieldText = new[,]{
{ "ID", "编号" },
{ "Name", "姓名" },
{ "CreateTime", "创建时间" }
};
//string[,] columnFieldText = null;
var buf = NpoiExcelHelper.DataTableToExcel(data, fileName, columnFieldText, sheetName);
Response.Buffer = true;
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.Charset = "UTF8";
Response.ContentEncoding = Encoding.UTF8;
Response.ContentType = "application/vnd.ms-excel";
string browser = Request.Browser.Browser;
if (browser.Contains("InternetExplorer"))
Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, Encoding.UTF8));
else
Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);
Response.AddHeader("Content-Length", buf.Length.ToString());
Response.Flush();
Response.BinaryWrite(buf);/// <summary>
/// 创建DataTable对象
/// </summary>
public DataTable CreateDataTable(int record)
{
//创建DataTable
DataTable dt = new DataTable("NewDt");
//创建自增长的ID列
DataColumn dc = dt.Columns.Add("ID", Type.GetType("System.Int32"));
dc.AutoIncrement = true; //自动增加
dc.AutoIncrementSeed = 1; //起始为1
dc.AutoIncrementStep = 1; //步长为1
dc.AllowDBNull = false; //非空
//创建其它列表
dt.Columns.Add(new DataColumn("Name", Type.GetType("System.String")));
dt.Columns.Add(new DataColumn("CreateTime", Type.GetType("System.DateTime")));
DataRow dr;
for (int i = 0; i < record; i++)
{
dr = dt.NewRow();
dr["Name"] = "名字" + i.ToString();
dr["CreateTime"] = DateTime.Now;
dt.Rows.Add(dr);
}
return dt;
}（2）Excel中数据导入DataTable中（支持指定Sheet名称 / 多个数据格式一致的Shee）
string fileName = "客户明细_0213023109.xls";
string sheetName = "客户明细1";
string[,] columnFieldText = new[,]{
{ "ID", "编号" },
{ "Name", "姓名" },
{ "CreateTime", "创建时间" }
};
//string[,] columnFieldText = null;
var dt = NpoiExcelHelper.ExcelToDataTable(Server.MapPath(fileName), columnFieldText, sheetName);到此这篇关于C#操作NPOI实现Excel数据导入导出的文章就介绍到这了,更多相关C# NPOIExcel数据导入导出内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持！
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