原文:C#_.NetCore_WebAPI项目_EXCEL数据导出（ExcelHelper_第二版_优化逻辑）
项目需要引用NPOI的Nuget包：DotNetCore.NPOI-v1.2.2
本篇文章是对WebAPI项目使用NPOI操作Excel时的帮助类：ExcelHelper的改进优化做下记录：
备注：下面的帮助类代码使用的文件格式为：xlsx文件，xlsx相对xls的优缺点代码里有注释，推荐使用xlsx文件保存数据！
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Microsoft.Net.Http.Headers;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
namespace PaymentAccountAPI.Helper
{
/// <summary>
/// EXCEL帮助类
/// </summary>
/// <typeparam name="T">泛型类</typeparam>
/// <typeparam name="TCollection">泛型类集合</typeparam>
public class ExcelHelp
{
private ILogger Logger = null;
public ExcelHelp(ILogger<ExcelHelp> logger)
{
this.Logger = logger;
}
/// <summary>
/// 将数据导出EXCEL
/// </summary>
/// <param name="tList">要导出的数据集</param>
/// <param name="fieldNameAndShowNameDic">键值对集合（键：字段名，值：显示名称）</param>
/// <param name="fileDirectoryPath">文件路径</param>
/// <param name="excelName">文件名（必须是英文或数字）</param>
/// <returns></returns>
public IWorkbook CreateOrUpdateWorkbook<T>(List<T> tList, Dictionary<string, string> fieldNameAndShowNameDic, IWorkbook workbook = null, string sheetName = "sheet1") where T : new()
{
//xls文件格式属于老版本文件，一个sheet最多保存65536行；而xlsx属于新版文件类型；
//Excel 07 - 2003一个工作表最多可有65536行，行用数字1—65536表示; 最多可有256列，列用英文字母A—Z，AA—AZ，BA—BZ，……，IA—IV表示；一个工作簿中最多含有255个工作表，默认情况下是三个工作表；
//Excel 2007及以后版本，一个工作表最多可有1048576行，16384列；
if (workbook == null)
{
workbook = new XSSFWorkbook();
//workbook = new HSSFWorkbook();
}
ISheet worksheet = workbook.CreateSheet(sheetName);
List<string> columnNameList = fieldNameAndShowNameDic.Values.ToList();
//设置首列显示
IRow row1 = worksheet.CreateRow(0);
ICell cell = null;
ICellStyle cellHeadStyle = workbook.CreateCellStyle();
//设置首行字体加粗
IFont font = workbook.CreateFont();
font.Boldweight = short.MaxValue;
cellHeadStyle.SetFont(font);
int cloumnCount = columnNameList.Count;
for (var i = 0; i < cloumnCount; i++)
{
cell = row1.CreateCell(i);
cell.SetCellValue(columnNameList[i]);
cell.CellStyle = cellHeadStyle;
}
//根据反射创建其他行数据
var raws = tList.Count;
Dictionary<string, PropertyInfo> titlePropertyDic = this.GetIndexPropertyDic<T>(fieldNameAndShowNameDic);
PropertyInfo propertyInfo = null;
T t = default(T);
for (int i = 0; i < raws; i++)
{
if (i % 10000 == 0)
{
this.Logger.LogInformation($"Excel已创建{i + 1}条数据");
}
row1 = worksheet.CreateRow(i + 1);
t = tList[i];
int cellIndex = 0;
foreach (var titlePropertyItem in titlePropertyDic)
{
propertyInfo = titlePropertyItem.Value;
cell = row1.CreateCell(cellIndex);
if (propertyInfo.PropertyType == typeof(int)
|| propertyInfo.PropertyType == typeof(decimal)
|| propertyInfo.PropertyType == typeof(double))
{
cell.SetCellValue(Convert.ToDouble(propertyInfo.GetValue(t) ?? 0));
}
else if (propertyInfo.PropertyType == typeof(DateTime))
{
cell.SetCellValue(Convert.ToDateTime(propertyInfo.GetValue(t)?.ToString()).ToString("yyyy-MM-dd HH:mm:ss"));
}
else if (propertyInfo.PropertyType == typeof(bool))
{
cell.SetCellValue(Convert.ToBoolean(propertyInfo.GetValue(t).ToString()));
}
else
{
cell.SetCellValue(propertyInfo.GetValue(t)?.ToString() ?? "");
}
cellIndex++;
}
//重要：设置行宽度自适应(大批量添加数据时，该行代码需要注释，否则会极大减缓Excel添加行的速度！)
//worksheet.AutoSizeColumn(i, true);
}
return workbook;
}
/// <summary>
/// 保存Workbook数据为文件
/// </summary>
/// <param name="workbook"></param>
/// <param name="fileDirectoryPath"></param>
/// <param name="fileName"></param>
public void SaveWorkbookToFile(IWorkbook workbook, string fileDirectoryPath, string fileName)
{
//xls文件格式属于老版本文件，一个sheet最多保存65536行；而xlsx属于新版文件类型；
//Excel 07 - 2003一个工作表最多可有65536行，行用数字1—65536表示; 最多可有256列，列用英文字母A—Z，AA—AZ，BA—BZ，……，IA—IV表示；一个工作簿中最多含有255个工作表，默认情况下是三个工作表；
//Excel 2007及以后版本，一个工作表最多可有1048576行，16384列；
MemoryStream ms = new MemoryStream();
//这句代码非常重要，如果不加，会报：打开的EXCEL格式与扩展名指定的格式不一致
ms.Seek(0, SeekOrigin.Begin);
workbook.Write(ms);
byte[] myByteArray = ms.GetBuffer();
fileDirectoryPath = fileDirectoryPath.TrimEnd(‘\\‘) + "\\";
if (!Directory.Exists(fileDirectoryPath))
{
Directory.CreateDirectory(fileDirectoryPath);
}
string filePath = fileDirectoryPath + fileName;
if (File.Exists(filePath))
{
File.Delete(filePath);
}
File.WriteAllBytes(filePath, myByteArray);
}
/// <summary>
/// 保存Workbook数据为下载文件
/// </summary>
public FileContentResult SaveWorkbookToDownloadFile(IWorkbook workbook)
{
MemoryStream ms = new MemoryStream();
//这句代码非常重要，如果不加，会报：打开的EXCEL格式与扩展名指定的格式不一致
ms.Seek(0, SeekOrigin.Begin);
workbook.Write(ms);
byte[] myByteArray = ms.GetBuffer();
//对于.xls文件
//application/vnd.ms-excel
//用于.xlsx文件。
//application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
MediaTypeHeaderValue mediaType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
mediaType.Encoding = System.Text.Encoding.UTF8;
return new FileContentResult(myByteArray, mediaType.ToString());
}
/// <summary>
/// 读取Excel数据
/// </summary>
/// <param name="filePath"></param>
/// <param name="fieldNameAndShowNameDic"></param>
/// <returns></returns>
public List<T> ReadDataList<T>(string filePath, Dictionary<string, string> fieldNameAndShowNameDic) where T : new()
{
List<T> tList = null;
T t = default(T);
//标题属性字典列表
Dictionary<string, PropertyInfo> titlePropertyDic = this.GetIndexPropertyDic<T>(fieldNameAndShowNameDic);
//标题下标列表
Dictionary<string, int> titleIndexDic = new Dictionary<string, int>(0);
PropertyInfo propertyInfo = null;
using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
IWorkbook xssfWorkbook = new XSSFWorkbook(fileStream);
var sheet = xssfWorkbook.GetSheetAt(0);
var rows = sheet.GetRowEnumerator();
tList = new List<T>(sheet.LastRowNum + 1);
//第一行数据为标题，
if (rows.MoveNext())
{
IRow row = (XSSFRow)rows.Current;
ICell cell = null;
string cellValue = null;
for (int i = 0; i < row.Cells.Count; i++)
{
cell = row.Cells[i];
cellValue = cell.StringCellValue;
if (titlePropertyDic.ContainsKey(cellValue))
{
titleIndexDic.Add(cellValue, i);
}
}
}
//从第2行数据开始获取
while (rows.MoveNext())
{
IRow row = (XSSFRow)rows.Current;
t = new T();
foreach (var titleIndexItem in titleIndexDic)
{
var cell = row.GetCell(titleIndexItem.Value);
if (cell != null)
{
propertyInfo = titlePropertyDic[titleIndexItem.Key];
if (propertyInfo.PropertyType == typeof(int))
{
propertyInfo.SetValue(t, Convert.ToInt32(cell.NumericCellValue));
}
else if (propertyInfo.PropertyType == typeof(decimal))
{
propertyInfo.SetValue(t, Convert.ToDecimal(cell.NumericCellValue));
}
else if (propertyInfo.PropertyType == typeof(double))
{
propertyInfo.SetValue(t, Convert.ToDouble(cell.NumericCellValue));
}
else if (propertyInfo.PropertyType == typeof(bool))
{
propertyInfo.SetValue(t, Convert.ToBoolean(cell.StringCellValue));
}
else if (propertyInfo.PropertyType == typeof(DateTime))
{
propertyInfo.SetValue(t, Convert.ToDateTime(cell.StringCellValue));
}
else
{
propertyInfo.SetValue(t, cell.StringCellValue);
}
}
}
tList.Add(t);
}
}
return tList ?? new List<T>(0);
}
/// <summary>
/// 根据属性名顺序获取对应的属性对象
/// </summary>
/// <param name="fieldNameList"></param>
/// <returns></returns>
private Dictionary<string, PropertyInfo> GetIndexPropertyDic<T>(Dictionary<string, string> fieldNameAndShowNameDic)
{
Dictionary<string, PropertyInfo> titlePropertyDic = new Dictionary<string, PropertyInfo>(fieldNameAndShowNameDic.Count);
List<PropertyInfo> tPropertyInfoList = typeof(T).GetProperties().ToList();
PropertyInfo propertyInfo = null;
foreach (var item in fieldNameAndShowNameDic)
{
propertyInfo = tPropertyInfoList.Find(m => m.Name.Equals(item.Key, StringComparison.OrdinalIgnoreCase));
titlePropertyDic.Add(item.Value, propertyInfo);
}
return titlePropertyDic;
}
}
}
原文地址：https://www.cnblogs.com/lonelyxmas/p/12065751.html
时间： 2024-10-22 02:49:12