NPOI projects need to reference the Nuget package: DotNetCore.NPOI-v1.2.2
Help class when this article is to use Excel to WebAPI NPOI operating items: ExcelHelper improvements optimized to do the next record:
NOTE: The following file formats used to help the class code: xlsx file, xls xlsx relative advantages and disadvantages of the code notes, recommended xlsx files saved data!
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"> generic class set </ typeParam> public class ExcelHelp { Private ILogger Logger = null ; public ExcelHelp (ILogger <ExcelHelp> Logger) { the this .Logger = Logger; } /// <Summary> / // the data export the EXCEL /// </ Summary> /// <param name = "tlist"> to export data sets </ param> /// <param name = "fieldNameAndShowNameDic"> key to set (button : field name value: display name) </ param> /// <param name = "fileDirectoryPath "> File Path</ param> /// <param name = "excelName"> filename (must be in English or digital) </ param> /// <returns A> </ returns A> public IWorkbook CreateOrUpdateWorkbook <T> (List <T> tlist , the Dictionary < String , String > fieldNameAndShowNameDic, IWorkbook Workbook = null , String sheetName = " sheet1 " ) the WHERE T: new new () { // XLS file format belongs to the old version of the file, save a sheet up to 65536 lines; and xlsx belong to the new file type; // Excel 07 - 2003 a worksheet can have up to 65536 rows, rows with numbers 1-65536 representation; There may be up to 256, row by letters AZ, AA-AZ, BA-BZ, ......, IA-IV represents; workbook contains a maximum of 255 sheets, the three sheets by default;// Excel 2007 and later versions, a sheet can be up to 1,048,576 rows, 16,384; IF (Workbook == null ) { Workbook = new new XSSFWorkbook (); // Workbook new new HSSFWorkbook = (); } ISheet Worksheet = Workbook. createSheet (sheetName); List < String > columnNameList = fieldNameAndShowNameDic.Values.ToList (); // set the first column shows the 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" )); } The else IF (propertyInfo.PropertyType == typeof ( BOOL )) { cell.SetCellValue (Convert.ToBoolean (propertyInfo.GetValue (T) .ToString ())); } the else { cell.SetCellValue (propertyInfo.GetValue (t) .ToString () ??? "" ); } the cellIndex ++ ; } // important: when you set the line width adaptation (adding large quantities of data that need the comment line, otherwise it will greatly slow down the Excel add rows speed!) //worksheet.AutoSizeColumn (I, to true); } return Workbook; } /// <Summary> /// Save Workbook data file /// </ Summary> /// <param name = "Workbook"> </ param> /// <param name = "fileDirectoryPath"> </ param> /// <param name = "fileName"> </ param> public void SaveWorkbookToFile (IWorkbook Workbook, String fileDirectoryPath, String fileName) { // XLS file format belongs the old version of the file, save a sheet up to 65536 lines; and xlsx belong to the new version of file types; //Excel 07 - 2003 a worksheet can have up to 65536 lines, digital lines represent 1-65536; can have up to 256 columns with letters AZ, AA-AZ, BA- BZ, ......, IA-IV represents ; workbook contains a maximum of 255 sheets, the three sheets by default; // Excel 2007 and later versions, a sheet can be up to 1,048,576 rows, 16384; the MemoryStream MS = new new the MemoryStream (); / / this code is very important, if not, will be reported: format inconsistent with the EXCEL open extension format specified ms.Seek ( 0 , SeekOrigin.Begin); workbook.Write (MS); byte [] = myByteArray MS. the 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 = newMemoryStream (); // This code is very important, if not, will be reported: Inconsistent format with the extension of the open EXCEL format specified ms.Seek ( 0 , SeekOrigin.Begin); workbook.Write (MS); byte [ ] = myByteArray ms.GetBuffer (); // for .xls files // file application / vnd.ms-Excel // for .xlsx files. // file application / vnd.openxmlformats-officedocument.spreadsheetml.sheet MediaTypeHeaderValue mediaType = new new MediaTypeHeaderValue ( " file 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); // title attribute dictionary listing the Dictionary < String , PropertyInfo> = titlePropertyDic the this .GetIndexPropertyDic <T> (fieldNameAndShowNameDic); // heading subscript listing the Dictionary < String , int > = titleIndexDic new new the Dictionary < String , int > ( 0 ); PropertyInfo PropertyInfo = null ; the using (= the fileStream fileStream new 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 new List <T> ( 0 ); } /// <Summary> /// Gets an object according to the attribute corresponding to the attribute name order /// </ Summary> /// <param name = "FieldNameList"> </ param> /// <Returns> </ Returns> Private the Dictionary < String , PropertyInfo> GetIndexPropertyDic <T> (the 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; } } }