WebApi2官网学习记录---Html Form Data

HTML Forms概述

<form action="api/values" method="post">

默认的method是GET，如果使用GET，表单数据被编码到URI中作为查询字符串；如果使用POST，表单数据放在Request body中，enctype属性指定编码类型：

编码方式(enctype)	描述
application/x-www-form-urlencoded	表单数据被编码成name/value形式，默认的编码方式
multipart/form-data	表单数据被编码成多部分的MIME消息，上传文件时使用

application/x-www-form-urlencoded

POST http://localhost:38899/api/updates/complex HTTP/1.1
Accept: text/html, application/xhtml+xml, /
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Content-Type: application/x-www-form-urlencoded
Content-Length: 47

status=Shopping+at+the+mall.&date=6%2F15%2F2012

注意：

默认情况下WebAPI获得复杂类型的参数使用Request body中，简单参数从URI中，可以使用[FromBody]强制从Request body中获取。由于WebAPI最多读取Request body一次，所以action仅有一个参数是来自Request body，如果需要获取多个值从Request body可以使用复杂类型。

对于简单参数，在Request body中消息的格式：

=value

multipart/form-data

POST http://localhost:50460/api/values/1 HTTP/1.1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------41184676334
Content-Length: 29278

-----------------------------41184676334
Content-Disposition: form-data; name="caption"

Summer vacation
-----------------------------41184676334
Content-Disposition: form-data; name="image1"; >filename="GrandCanyon.jpg"
Content-Type: image/jpeg

(Binary data not shown)
-----------------------------41184676334--

• Content-Disposition:包含上传控件的名字、上传的文件的名字
  

• Content-Type：描述了这部分数据的类型。默认是text/plain可以省略

  上传的一个demo

  public class UploadController : ApiController
      {
          public async Task<HttpResponseMessage> PostFormData()
          {
              if (!Request.Content.IsMimeMultipartContent())
              {
                  throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType); 
              }
  
              string root = HttpContext.Current.Server.MapPath("~/App_Data");
              var provider = new MultipartFormDataStreamProvider(root);
  
              try
              {
                  await Request.Content.ReadAsMultipartAsync(provider);
  
                  foreach (MultipartFileData file in provider.FileData)
                  {
                      //文件名
                      Trace.WriteLine(file.Headers.ContentDisposition.FileName);
                      //服务端存储文件路径
                      Trace.WriteLine("Server file path:"+file.LocalFileName);
                  }
                  //对应的name/value
                  foreach (var key in provider.FormData.AllKeys)
                  {
                      foreach (var val in provider.FormData.GetValues(key))
                      {
                          Trace.WriteLine(string.Format("{0}: {1}", key, val));
                      }
                  }
                  return Request.CreateResponse(HttpStatusCode.OK);
              }
              catch (Exception e)
              {
                  return Request.CreateErrorResponse(HttpStatusCode.InternalServerError,e);
                  throw;
              }
          }
      }