#region 文件上传  可以带参数
        [HttpPost("upload")]
        public JsonResult uploadProject(IFormFile file, string userId)
        {
            if (file != null)
            {
                var fileDir = "D:\\aaa";
                if (!Directory.Exists(fileDir))
                {
                    Directory.CreateDirectory(fileDir);
                }
                //文件名称
                string projectFileName = file.FileName;
 
                //上传的文件的路径
                string filePath = fileDir + $@"\{projectFileName}";
                using (FileStream fs = System.IO.File.Create(filePath))
                {
                    file.CopyTo(fs);
                    fs.Flush();
                }
                return Json("ok");
            }else{
                return Json("no");
            }
        }
        #endregion

<template>
<div>
    <form>
        <input type="text" value="" v-model="projectName" placeholder="请输入项目名称">
        <input type="file" v-on:change="getFile($event)">
        <button v-on:click="submitForm($event)">上传</button>
    </form>
</div>
</template>
 
<script>
///这个组件是用于上传bdls文件的组件
export default {
  data() {
    return {
      uploadURL: "/Home/Upload",
      projectName: "",
      file: ""
    };
  },
  methods: {
    getFile(event) {
      this.file = event.target.files[0];
      console.log(this.file);
    },
    submitForm(event) {
      event.preventDefault();
      let formData = new FormData();
      formData.append("file", this.file);
 
      let config = {
        headers: {
          "Content-Type": "multipart/form-data"
        }
      };
 
      this.$http
        .post(this.uploadURL, formData, config)
        .then(function(response) {
          if (response.status === 200) {
            console.log(response.data);
          }
        });
    }
  }
};
</script>
 
<style lang="scss" scoped>
</style>

<template>
<div>
    <el-upload
      class="upload-css"
      :file-list="uploadFiles"
      ref="upload"
      :on-success="upLoadSuccess"
      :on-error="upLoadError"
      :action="uploadURL"
      :auto-upload="false">
        <el-button slot="trigger" size="small" type="primary">选取文件</el-button>
        <el-button style="margin-left: 10px;" size="small" type="success" @click="submitUpload">上传到服务器</el-button>
    </el-upload>
</div>
</template>
 
<script>
import Vue from "vue";
import { Upload, Button } from "element-ui";
Vue.use(Upload);
Vue.use(Button);
 
export default {
  props: [],
  data() {
    return {
      projectName: "",
      //uploadURL: "/project/upload?a=1",
      uploadFiles: [] //上传的文件列表
    };
  },
  computed: {
    //文件的上传路径
    //附带用户id和项目名称
    uploadURL: function() {
      //var userId = this.$store.state.userId;
      return "/project/upload?userId=" + 1;
    }
  },
  methods: {
    //文件上传
    submitUpload() {
      this.$refs.upload.submit();
    },
    //文件上传成功时的钩子
    upLoadSuccess(response, file, fileList) {
      if (response == "ok") {
        console.log(response + "已上传" + file);
        console.log("项目添加成功");
      } else {
        console.log("项目添加失败");
      }
    },
    //文件上传失败时的钩子
    upLoadError(response, file, fileList) {
      console.log("项目添加失败");
    }
  }
};
</script>
 
<style lang="scss" scoped>
</style>

public FileResult downloadRequest()
        {
            //var addrUrl = webRootPath + "/upload/thumb.jpg";
            var addrUrl = "D:/aaa/thumb.jpg";
 
            var stream = System.IO.File.OpenRead(addrUrl);
 
            string fileExt = Path.GetExtension("thumb.jpg");
 
            //获取文件的ContentType
 
            var provider = new FileExtensionContentTypeProvider();
 
            var memi = provider.Mappings[fileExt];
 
            return File(stream, memi, Path.GetFileName(addrUrl));
        }

...
...
 
downloadRequest() {   
    let url = "Home/downloadRequest"; //可以在路径中传递参数
    window.location.href = url;
 },

public FileContentResult downloadRequest1()
        {
            //string webRootPath = _hostingEnvironment.WebRootPath;
            //var addrUrl = webRootPath + "/upload/thumb.jpg";
            var addrUrl = "D:/aaa/wyy.exe";
 
            /*var stream = System.IO.File.OpenRead(addrUrl);
 
            string fileExt = Path.GetExtension("thumb.jpg");
 
            //获取文件的ContentType
 
            var provider = new FileExtensionContentTypeProvider();
 
            var memi = provider.Mappings[fileExt];
 
            return File(stream, memi, Path.GetFileName(addrUrl));*/
 
            //return stream;
            byte[] fileBytes = System.IO.File.ReadAllBytes(addrUrl);
            string fileName = "wyy.exe";
            return File(fileBytes, System.Net.Mime.MediaTypeNames.Application.Octet, fileName); //关键语句
        }

<el-button type="primary" v-on:click="downloadRequest1">下载文件11</el-button>
...
...
...
    downloadRequest1() {
      axios({
        // 用axios发送post请求
        method: "post",
        url: "Home/downloadRequest1", // 请求地址 ，也可以传递参数
        headers: {
          //可以自定义header
          gggg: "gggggggggggggggggggggggggggggggggggggggggggggggggggg"  //可以携带token
        },
        responseType: "blob" // 表明返回服务器返回的数据类型
      }).then(res => {
        // 处理返回的文件流
        //主要是将返回的data数据通过blob保存成文件
        var content = res.data;
        var blob = new Blob([content]);
        var fileName = "wyy.exe"; //要保存的文件名称
        if ("download" in document.createElement("a")) {
          // 非IE下载
          var elink = document.createElement("a");
          elink.download = fileName;
          elink.style.display = "none";
          elink.href = URL.createObjectURL(blob);
          document.body.appendChild(elink);
          elink.click();
          URL.revokeObjectURL(elink.href); // 释放URL 对象
          document.body.removeChild(elink);
        } else {
          // IE10+下载
          navigator.msSaveBlob(blob, fileName);
        }
        console.log(res);
      });
    }