1、在项目中经常需要把报表下载为csv格式的文件，如何在C#中写csv文件，以下为一个简化的例子，不使用任何控件，旨在说明用法。

前端view

下载结果

2、创建一个MVC项目（Intranet Application），项目结构如下

3、各部分代码：

3.1、定义实体

using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace MvcDownLoadCsv.Models{    public class Person    {        public string Name { get; set; }        public string Code { get; set; }        public string Department { get; set; }    }}

3.2、定义共用方法，将object数据转换为HtmlString，

using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace MvcDownLoadCsv.Extensions{    public static class DataTypeExtensions    {        public static HtmlString ToHtmlCsv(this object o)        {            if (o == null) return new HtmlString("");            var s = o.ToString();            if (s.Length == 0) return new HtmlString(s);            s = s.Replace("\"", "\"\"");            HtmlString hs = new HtmlString(s.ToString());            return new HtmlString(string.Concat("\"", s, "\""));        }    }}

3.3、定义公用方法，把Model数据转换为csv格式文件

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using System.Text;using System.IO;using System.Text.RegularExpressions;namespace MvcDownLoadCsv{    public class CsvDownloadResult : ActionResult    {        public CsvDownloadResult(string name, object model)        {            this.name = name;            this.model = model;        }        private string name;        private object model;        public override void ExecuteResult(ControllerContext context)        {            context.HttpContext.Response.Clear();            context.HttpContext.Response.AddHeader("content-disposition", string.Format("attachment; filename=My.{0}.csv", name));            context.HttpContext.Response.ContentEncoding = Encoding.GetEncoding(1252);// Use ANSI encoding            context.HttpContext.Response.ContentType = "application/vnd.ms-excel";            var csv = "";            using (StringWriter sw = new StringWriter())            {                var viewResult = ViewEngines.Engines.FindPartialView(context, name + "Csv");                var viewContext = new ViewContext(context, viewResult.View, new ViewDataDictionary(model), new TempDataDictionary(), sw);                viewResult.View.Render(viewContext, sw);                csv = sw.GetStringBuilder().ToString();                csv = Regex.Replace(csv, "\r\n[ ]+\r\n[ ]+", "\r\n");                csv = Regex.Replace(csv, ",\r\n[ ]*", ",");            }            context.HttpContext.Response.Write(csv);            context.HttpContext.Response.End();        }    }}

此例子中context最后为：

\Person Report\"\r\n\r\n\"Name\",\"Person Code\",\"Person Department\",\r\n\"a\" ,\"1\" ,\"Developer\" ,\r\n\"b\" ,\"2\" ,\"Test\" ,\r\n\"c\" ,\"3\" ,\"HR\" ,\r\n"

\r是回车，英文是Carriage return，表示使光标下移一格

\n是换行，英文是New line，表示使光标到行首

\r\n表示回车换行

 

3.4、定义csv文件格式

@using MvcDownLoadCsv.Extensions@model List
      
       "Person Report"@if (Model.Count == 0){
     
       
        "No Person find."
       }else{
     
       
        "Name","Person Code","Person Department",
           foreach (var item in Model)    {                @item.Name.ToHtmlCsv() 
       
        ,
               @item.Code.ToHtmlCsv() 
       
        ,
               @item.Department.ToHtmlCsv() 
       
        ,
               
           }}
      

3.5、后台方法，构造数据，定义响应前端下载的方法

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using MvcDownLoadCsv.Models;namespace MvcDownLoadCsv.Controllers{    public class HomeController : Controller    {        public ActionResult Index()        {            ViewBag.Message = "Welcome to ASP.NET MVC!";                       return View(GetPerson());        }        public ActionResult About()        {            return View();        }        public List
      
        GetPerson()        {            List
       
         lst = new List
        
         ()            {                new Person() { Name = "a", Code = "1", Department = "Developer" },                new Person() { Name = "b", Code = "2", Department = "Test" },                new Person() { Name = "c", Code = "3", Department = "HR" }            };            return lst;        }        [HttpPost]        public ActionResult DownloadCsv()        {            //Person为定义报表格式的cshtml文件名称， GetPerson()返回的是报表数据            return new CsvDownloadResult("Person", GetPerson());        }    }   }
        
       
      

3.6、前端页面view

@model List
      
       @{    ViewBag.Title = "Home Page";}    
       
       
@ViewBag.Message
       
    To learn more about ASP.NET MVC visit http://asp.net/mvc.
 
       
                @if (Model.Count > 0)        {            
        download            
        copy            
        downloadForPopup        } 
       
 
       
    
        
            
        
        
    @{               foreach (var item in Model)        {        
        }    }
             
          
                   
Name
                   
Code
                   
Department
              
          
                       
@item.Name
                       
@item.Code
                       
@item.Department
                  
         
        
       
      

。