C#使用NPOI将List数据导出到Excel文档
时间：2022-10-30 11:07:46 | 栏目：.NET代码 | 点击：次
NPOI是一个开源的C#读写Excel、WORD等微软OLE2组件文档的项目。使用 NPOI 可以在没有安装 Office 或者相应环境的机器上对 WORD/EXCEL 文档进行读写。
这里简单封装了一个使用NPOI导出Excel的DLL，方便项目使用。步骤如下：
1、NuGet包管理器添加对NPOI和log4net的安装引用
2、添加Excel属性信息类ExcelProperty.cs
/// <summary>
/// 用于定义导出的excel属性
/// </summary>
public class ExcelProperty
{
public ExcelProperty() { }
/// <summary>
/// 文件基本属性
/// </summary>
/// <param name="company">公司名称</param>
/// <param name="author">作者信息</param>
/// <param name="ApplicationName">创建程序信息</param>
/// <param name="Comments">填加xls文件备注</param>
/// <param name="title">填加xls文件标题信息</param>
/// <param name="Subject">填加文件主题信息</param>
public ExcelProperty(string company, string author, string applicationName, string comments, string title, string subject)
{
this.Company = company;
this.Author = author;
this.ApplicationName = applicationName;
this.Comments = comments;
this.Title = title;
this.Subject = subject;
}
/// <summary>
/// 公司名称
/// </summary>
private string company = "";
/// <summary>
/// 公司名称
/// </summary>
public string Company
{
get { return company; }
set { company = value; }
}
/// <summary>
/// 作者信息
/// </summary>
private string author = "";
/// <summary>
/// 作者信息
/// </summary>
public string Author
{
get { return author; }
set { author = value; }
}
/// <summary>
/// 创建程序信息
/// </summary>
private string applicationName = "";
/// <summary>
/// 创建程序信息
/// </summary>
public string ApplicationName
{
get { return applicationName; }
set { applicationName = value; }
}
/// <summary>
///填加xls文件备注
/// </summary>
private string comments = "";
/// <summary>
///填加xls文件备注
/// </summary>
public string Comments
{
get { return comments; }
set { comments = value; }
}
/// <summary>
/// 填加xls文件标题信息
/// </summary>
private string title = "";
/// <summary>
/// 填加xls文件标题信息
/// </summary>
public string Title
{
get { return title; }
set { title = value; }
}
/// <summary>
/// 填加文件主题信息
/// </summary>
private string subject = "";
/// <summary>
/// 填加文件主题信息
/// </summary>
public string Subject
{
get { return subject; }
set { subject = value; }
}
}
3、添加Excel导出类ExcelExportHelper.cs
using log4net;
using NPOI.HPSF;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Reflection;
using System.Text;
namespace NPOIExcelExportHelper
{
public class ExcelExportHelper
{
//委托
public delegate void ExportResult(bool res);
public event ExportResult ExportResultEvent;
//构造函数
public ExcelExportHelper() { }
public ExcelExportHelper(ILog loghelper)
{
this.LogHelper = loghelper;
}
/// <summary>
/// 日志
/// </summary>
private ILog LogHelper;
/// <summary>
/// 要导出的Excel对象
/// </summary>
private HSSFWorkbook workbook = null;
/// <summary>
/// 要导出的Excel对象属性
/// </summary>
private HSSFWorkbook Workbook
{
get
{
if (workbook == null)
{
workbook = new HSSFWorkbook();
}
return workbook;
}
set { workbook = value; }
}
/// <summary>
/// 设置Excel文件基本属性
/// </summary>
/// <param name="ep">属性</param>
public void SetExcelProperty(ExcelProperty ep)
{
DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = ep.Company;//填加xls文件公司信息
Workbook.DocumentSummaryInformation = dsi;
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
si.Author = ep.Author; //填加xls文件作者信息
si.ApplicationName = ep.ApplicationName; //填加xls文件创建程序信息
si.Comments = ep.Comments; //填加xls文件备注
si.Title = ep.Title; //填加xls文件标题信息
si.Subject = ep.Subject;//填加文件主题信息
si.CreateDateTime = DateTime.Now;
Workbook.SummaryInformation = si;
}
/// <summary>
/// 泛型列表List导出到Excel文件
/// </summary>
/// <param name="list">源List表</param>
/// <param name="strHeaderText">标题信息</param>
/// <param name="strFileName">保存路径</param>
/// <param name="titles">列名</param>
public void ExportToFile<T>(List<T> list, string strHeaderText, string strFileName, string[] titles = null)
{
try
{
//转换数据源
DataTable dtSource = ListToDataTable(list, titles);
//开始导出
Export(dtSource, strHeaderText, strFileName);
System.GC.Collect();
ExportResultEvent?.Invoke(true);
}
catch (Exception ex)
{
if (LogHelper != null)
LogHelper.Error(string.Format("ExportToFile error:{0}", ex));
ExportResultEvent?.Invoke(false);
}
}
/// <summary>
/// DataTable导出到Excel文件
/// </summary>
/// <param name="dtSource">源DataTable</param>
/// <param name="strHeaderText">标题信息</param>
/// <param name="strFileName">保存路径</param>
public void Export(DataTable dtSource, string strHeaderText, string strFileName)
{
using (MemoryStream ms = Export(dtSource, strHeaderText))
{
using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
{
byte[] data = ms.ToArray();
fs.Write(data, 0, data.Length);
fs.Flush();
}
}
}
/// <summary>
/// DataTable导出到Excel的MemoryStream
/// </summary>
/// <param name="dtSource">源DataTable</param>
/// <param name="strHeaderText">标题信息</param>
private MemoryStream Export(DataTable dtSource, string strHeaderText)
{
ISheet sheet = Workbook.CreateSheet();
ICellStyle dateStyle = Workbook.CreateCellStyle();
IDataFormat format = Workbook.CreateDataFormat();
dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");
//取得列宽
int[] arrColWidth = new int[dtSource.Columns.Count];
foreach (DataColumn item in dtSource.Columns)
{
arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
}
for (int i = 0; i < dtSource.Rows.Count; i++)
{
for (int j = 0; j < dtSource.Columns.Count; j++)
{
int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
if (intTemp > arrColWidth[j])
{
arrColWidth[j] = intTemp;
}
}
}
int rowIndex = 0;
foreach (DataRow row in dtSource.Rows)
{
#region 新建表，填充表头，填充列头，样式
if (rowIndex == 65535 || rowIndex == 0)
{
if (rowIndex != 0)
{
sheet = Workbook.CreateSheet();
}
#region 表头及样式
{
IRow headerRow = sheet.CreateRow(0);
headerRow.HeightInPoints = 25;
headerRow.CreateCell(0).SetCellValue(strHeaderText);
ICellStyle headStyle = Workbook.CreateCellStyle();
headStyle.Alignment = HorizontalAlignment.Center;
IFont font = Workbook.CreateFont();
font.FontHeightInPoints = 20;
font.Boldweight = 700;
headStyle.SetFont(font);
headerRow.GetCell(0).CellStyle = headStyle;
//CellRangeAddress四个参数为：起始行，结束行，起始列，结束列
sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, dtSource.Columns.Count - 1));
}
#endregion
#region 列头及样式
{
IRow headerRow = sheet.CreateRow(1);
ICellStyle headStyle = Workbook.CreateCellStyle();
headStyle.Alignment = HorizontalAlignment.Center;
IFont font = Workbook.CreateFont();
font.FontHeightInPoints = 10;
font.Boldweight = 700;
headStyle.SetFont(font);
foreach (DataColumn column in dtSource.Columns)
{
headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
//设置列宽
sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);
}
}
#endregion
rowIndex = 2;
}
#endregion
#region 填充内容
IRow dataRow = sheet.CreateRow(rowIndex);
foreach (DataColumn column in dtSource.Columns)
{
ICell newCell = dataRow.CreateCell(column.Ordinal);
string drValue = row[column].ToString();
switch (column.DataType.ToString())
{
case "System.String"://字符串类型
newCell.SetCellValue(drValue);
break;
case "System.DateTime"://日期类型
DateTime dateV;
DateTime.TryParse(drValue, out dateV);
newCell.SetCellValue(dateV);
newCell.CellStyle = dateStyle;//格式化显示
break;
case "System.Boolean"://布尔型
bool boolV = false;
bool.TryParse(drValue, out boolV);
newCell.SetCellValue(boolV);
break;
case "System.Int16"://整型
case "System.Int32":
case "System.Int64":
case "System.Byte":
int intV = 0;
int.TryParse(drValue, out intV);
newCell.SetCellValue(intV);
break;
case "System.Decimal"://浮点型
case "System.Double":
double doubV = 0;
double.TryParse(drValue, out doubV);
newCell.SetCellValue(doubV);
break;
case "System.DBNull"://空值处理
newCell.SetCellValue("");
break;
default:
newCell.SetCellValue("");
break;
}
}
#endregion
rowIndex++;
}
using (MemoryStream ms = new MemoryStream())
{
Workbook.Write(ms);
ms.Flush();
ms.Position = 0;
return ms;
}
}
/// <summary>
/// 泛型列表List转换为DataTable
/// </summary>
/// <typeparam name="T">泛型实体</typeparam>
/// <param name="list">要转换的列表</param>
/// <param name="titles">标题</param>
/// <returns></returns>
public DataTable ListToDataTable<T>(List<T> list, string[] titles)
{
DataTable dt = new DataTable();
Type listType = typeof(T);
PropertyInfo[] properties = listType.GetProperties();
//标题行
if (titles != null && properties.Length == titles.Length)
{
for (int i = 0; i < properties.Length; i++)
{
PropertyInfo property = properties[i];
dt.Columns.Add(new DataColumn(titles[i], property.PropertyType));
}
}
else
{
for (int i = 0; i < properties.Length; i++)
{
PropertyInfo property = properties[i];
dt.Columns.Add(new DataColumn(property.Name, property.PropertyType));
}
}
//内容行
foreach (T item in list)
{
DataRow dr = dt.NewRow();
for (int i = 0; i < dt.Columns.Count; i++)
{
dr[i] = properties[i].GetValue(item, null);
}
dt.Rows.Add(dr);
}
return dt;
}
}
}
调用方法：
1、新建一项目，添加对上述DLL的引用
2、创建TestItem测试类
public class TestItem
{
public string Name { get; set; }
public int Id { get; set; }
public string Date { get; set; }
public TestItem(string name, int id, string date)
{
Name = name;
Id = id;
Date = date;
}
}
3、调用
private void GetList()
{
List<TestItem> list = new List<TestItem>();
for (int i = 0; i < 100000; i++)
{
list.Add(new TestItem("姓名" + i, i, "2020-04-21"));
}
ExcelExportHelper exportHelper = new ExcelExportHelper();
exportHelper.ExportResultEvent += ExportHelper_ExportResultEvent;
exportHelper.SetExcelProperty(new ExcelProperty("TEST", "DNA", "ExcelExport", "", "统计查询", "统计信息"));
exportHelper.ExportToFile(list, "查询结果统计", @"C:\Test.xls", new string[]{ "姓名", "编号", "日期"});
}
private void ExportHelper_ExportResultEvent(bool res)
{
Console.Write(res);
}
4、结果
