How to code MVC Web Api Post method for file uploa

问题:

I am following this tutorial on uploading files to a server from android, but I cannot seem to get the code right on the server side. Can somebody please help me code the Web Api post method that would work with that android java uploader? My current web api controller class looks like this:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web;
using System.Web.Http;

namespace WSISWebService.Controllers
{
    public class FilesController : ApiController
    {
        // GET api/files
        public IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }

        // GET api/files/5
        public string Get(int id)
        {
            return "value";
        }

        // POST api/files
        public string Post([FromBody]string value)
        {
            var task = this.Request.Content.ReadAsStreamAsync();
            task.Wait();
            Stream requestStream = task.Result;

            try
            {
                Stream fileStream = File.Create(HttpContext.Current.Server.MapPath("~/" + value));
                requestStream.CopyTo(fileStream);
                fileStream.Close();
                requestStream.Close();
            }
            catch (IOException)
            {
                //  throw new HttpResponseException("A generic error occured. Please try again later.", HttpStatusCode.InternalServerError);
            }

            HttpResponseMessage response = new HttpResponseMessage();
            response.StatusCode = HttpStatusCode.Created;
            return response.ToString();
        }          

        // PUT api/files/5
        public void Put(int id, [FromBody]string value)
        {
        }

        // DELETE api/files/5
        public void Delete(int id)
        {
        }
    }
}

I am pretty desperate to get this working as the deadline is tuesday. If anybody could help that would be much appreciated.

回答1:

you can post a files as multipart/form-data

    // POST api/files
    public async Task<HttpResponseMessage> Post()
    {
        // Check if the request contains multipart/form-data.
        if (!Request.Content.IsMimeMultipartContent())
        {
            throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
        }

        string root = HttpContext.Current.Server.MapPath("~/App_Data");
        var provider = new MultipartFormDataStreamProvider(root);

        string value;

        try
        {
            // Read the form data and return an async data.
            var result = await Request.Content.ReadAsMultipartAsync(provider);

            // This illustrates how to get the form data.
            foreach (var key in provider.FormData.AllKeys)
            {
                foreach (var val in provider.FormData.GetValues(key))
                {
                    // return multiple value from FormData
                    if (key == "value")
                        value = val;
                }
            }                       

            if (result.FileData.Any())
            {                    
                // This illustrates how to get the file names for uploaded files.
                foreach (var file in result.FileData)
                {
                    FileInfo fileInfo = new FileInfo(file.LocalFileName);
                    if (fileInfo.Exists)
                    {
                       //do somthing with file
                    }
                }
            }


            HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created, value);
            response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = files.Id }));
            return response;
        }
        catch (System.Exception e)
        {
            return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, e);
        }
    }