将模型导出为ex​​cel / csv web api泛型方法

Question

我的ApiController中有这个API方法：

 [HttpGet]
        [Route("export")]
        public HttpResponseMessage Export([FromUri] int projectId)
        {
            StringWriter sw = new StringWriter();
            sw.WriteLine("\"KeyId\",\"PageName\",\"KeyType\",\"KeyName\",\"LanguageCode\"," +
                         "\"KeyStatus\",\"KeyValue\",\"DateCreated\",\"DateChanged\",\"UserId\",\"KeysCount\"");

            var export = _projectService.GetExportModel(projectId);

            foreach (var row in export)
            {
                sw.WriteLine(string.Format("\"{0}\",\"{1}\",\"{2}\",\"{3}\",\"{4}\"," +
                                           "\"{5}\",\"{6}\",\"{7}\",\"{8}\",\"{9}\"",
                                           row.KeyId, row.PageName, row.KeyType, row.LanguageCode,
                                           row.KeyStatus,row.KeyValue, row.DateCreated, row.DateChanged,
                                           row.UserId, row.KeysCount));
            }

            var res = Request.CreateResponse(HttpStatusCode.OK);
            res.Content = new StringContent(sw.ToString(), Encoding.UTF8, "text/csv");
            res.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = "Export.csv" };

            return res;
        }

在_projectService.GetExportModel我得到List<ExportExcelModel>：

public class ExportExcelModel
    {
        public long KeyId { get; set; }
        public string PageName { get; set; }
        public KeyType KeyType { get; set; }
        public string KeyName { get; set; }
        public string LanguageCode { get; set; }
        public KeyValueStatus KeyStatus { get; set; }
        public string KeyValue { get; set; }
        public DateTime DateCreated { get; set; }
        public DateTime? DateChanged { get; set; }
        public int UserId { get; set; }
        public long KeysCount { get; set; }
    }

这种方法效果很好，但都是硬编码的。在功能中，如果我向模型添加新属性，我将需要更新StringWriter并将此参数添加到foreach循环。我正在寻找更通用的方法来做到这一点。我想更新我的模型并在CSV中查看此更改，而无需更改webApi控制器中的任何行。这可能吗？

Answer 1

我知道我来这里不晚，但我认为这可能对其他人有帮助

查看这篇文章 https://www.codeproject.com/Articles/1241654/Export-to-Excel-using-NPOI-Csharp-and-WEB-API

它使用NPOI DLL，并且要包含2个cs文件，然后您就可以了

以下是第一个供参考的文件 AbstractDataExport.cs ：

using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;

namespace GenericExcelExport.ExcelExport
{
    public interface IAbstractDataExport
    {
        HttpResponseMessage Export(List exportData, string fileName, string sheetName);
    }

    public abstract class AbstractDataExport : IAbstractDataExport
    {
        protected string _sheetName;
        protected string _fileName;
        protected List _headers;
        protected List _type;
        protected IWorkbook _workbook;
        protected ISheet _sheet;
        private const string DefaultSheetName = "Sheet1";

        public HttpResponseMessage Export
              (List exportData, string fileName, string sheetName = DefaultSheetName)
        {
            _fileName = fileName;
            _sheetName = sheetName;

            _workbook = new XSSFWorkbook(); //Creating New Excel object
            _sheet = _workbook.CreateSheet(_sheetName); //Creating New Excel Sheet object

            var headerStyle = _workbook.CreateCellStyle(); //Formatting
            var headerFont = _workbook.CreateFont();
            headerFont.IsBold = true;
            headerStyle.SetFont(headerFont);

            WriteData(exportData); //your list object to NPOI excel conversion happens here

            //Header
            var header = _sheet.CreateRow(0);
            for (var i = 0; i < _headers.Count; i++)
            {
                var cell = header.CreateCell(i);
                cell.SetCellValue(_headers[i]);
                cell.CellStyle = headerStyle;
            }

            for (var i = 0; i < _headers.Count; i++)
            {
                _sheet.AutoSizeColumn(i);
            }

            using (var memoryStream = new MemoryStream()) //creating memoryStream
            {
                _workbook.Write(memoryStream);
                var response = new HttpResponseMessage(HttpStatusCode.OK)
                {
                    Content = new ByteArrayContent(memoryStream.ToArray())
                };

                response.Content.Headers.ContentType = new MediaTypeHeaderValue
                       ("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
                response.Content.Headers.ContentDisposition = 
                       new ContentDispositionHeaderValue("attachment")
                {
                    FileName = $"{_fileName}_{DateTime.Now.ToString("yyyyMMddHHmmss")}.xlsx"
                };

                return response;
            }
        }

        //Generic Definition to handle all types of List
        public abstract void WriteData(List exportData);
    }
}

这是第二个也是最后一个文件 AbstractDataExportBridge.cs ：

using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Text.RegularExpressions;

namespace GenericExcelExport.ExcelExport
{
    public class AbstractDataExportBridge : AbstractDataExport
    {
        public AbstractDataExportBridge()
        {
            _headers = new List<string>();
            _type = new List<string>();
        }

        public override void WriteData<T>(List<T> exportData)
        {
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));

            DataTable table = new DataTable();

            foreach (PropertyDescriptor prop in properties)
            {
                var type = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
                _type.Add(type.Name);
                table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? 
                                  prop.PropertyType);
                string name = Regex.Replace(prop.Name, "([A-Z])", " $1").Trim(); //space separated 
                                                                           //name by caps for header
                _headers.Add(name);
            }

            foreach (T item in exportData)
            {
                DataRow row = table.NewRow();
                foreach (PropertyDescriptor prop in properties)
                    row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;
                table.Rows.Add(row);
            }

            IRow sheetRow = null;

            for (int i = 0; i < table.Rows.Count; i++)
            {
                sheetRow = _sheet.CreateRow(i + 1);
                for (int j = 0; j < table.Columns.Count; j++)
                {
                    ICell Row1 = sheetRow.CreateCell(j);

                    string type = _type[j].ToLower();
                    var currentCellValue = table.Rows[i][j];

                    if (currentCellValue != null && 
                        !string.IsNullOrEmpty(Convert.ToString(currentCellValue)))
                    {
                        if (type == "string")
                        {
                            Row1.SetCellValue(Convert.ToString(currentCellValue));
                        }
                        else if (type == "int32")
                        {
                            Row1.SetCellValue(Convert.ToInt32(currentCellValue));
                        }
                        else if (type == "double")
                        {
                            Row1.SetCellValue(Convert.ToDouble(currentCellValue));
                        }
                    }
                    else
                    {
                        Row1.SetCellValue(string.Empty);
                    }
                }
            }
        }
    }
}

提供了更多信息的参考链接