public class PicData
    {
      public string Msg { get; set; }
    }

    [HttpPost]
    public async Task<bool> InsertPicture([FromServices]IHostingEnvironment environment)
    {
      var data = new PicData();
      string path = string.Empty;
      var files = Request.Form.Files;
      if (files == null || files.Count() <= 0)
      {
        data.Msg = "请选择上传的文件。";
        return false;
      }

      //格式限制
      var allowType = new string[] {"image/jpg", "image/png", "image/jpeg"};
      if (files.Any(c => allowType.Contains(c.ContentType)))
      {
        if (files.Sum(c => c.Length) <= 1024 * 1024 * 4)
        {
          foreach (var file in files)
          {
            string strpath = Path.Combine("Upload", DateTime.Now.ToString("MMddHHmmss") + file.FileName);
            path = Path.Combine(environment.WebRootPath, strpath);

            using (var stream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
              await file.CopyToAsync(stream);
            }
          }

          data.Msg = "上传成功";
          return true;
        }
        else
        {
          data.Msg = "图片过大";
          return false;
        }
      }
      else

      {
        data.Msg = "图片格式错误";
        return false;
      }
    }

string strpath = Path.Combine("Upload", DateTime.Now.ToString("MMddHHmmss") + file.FileName);

public void ConfigureServices(IServiceCollection services)
    {
      services.AddMvc();
      services.AddCors(options =>
      {
        options.AddPolicy("hehe", p => p.AllowAnyMethod()// 允许任何方法 GET,POST,PUT,DELETE, OPTIONS
            .AllowAnyHeader()    // 允许任何请求头
            .AllowAnyOrigin()    // 允许任何地址
        );
      });
    }

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
      app.UseStaticFiles(); app.UseCors("hehe");
      if (env.IsDevelopment())
      {
        app.UseDeveloperExceptionPage();
      }
      app.UseMvc();
    }

import iView from 'iview';
import 'iview/dist/styles/iview.css';
import locale from 'iview/dist/locale/en-US';

Vue.use(iView, { locale });

<template>
 <div id="app">
  
  <Upload action="http://localhost:53688/api/Index">
    <Button icon="ios-cloud-upload-outline">Upload files</Button>
  </Upload>

 </div>
</template>