vue实现的上传图片到数据库并显示到页面功能示例

<div class="form-signin-heading" id="btnupload" @change="upload">上传图片</div>
<input type="file" name="avatar" id="avatar" multiple="multiple" @change="upload">
<img :src="'http://localhost:8888'+item.photos_url" alt=""/>

mounted: function () {
 var upload = document.getelementbyid("btnupload");
 var avatar = document.getelementbyid("avatar");
 upload.onclick =function(){
  avatar.click(); //注意ie的兼容性
 };
}

let multer=require('multer');
let storage = multer.diskstorage({
  //设置上传后文件路径，uploads文件夹会自动创建。
  destination: function (req, file, cb) {
    cb(null, './public/uploads')
  },
  //给上传文件重命名，获取添加后缀名
  filename: function (req, file, cb) {
    let fileformat = (file.originalname).split(".");
    cb(null, file.fieldname + '-' + date.now() + "." + fileformat[fileformat.length - 1]);
  }
});
//添加配置文件到multer对象。
let upload = multer({
  storage: storage
});
module.exports = upload;

var muilter = require('./upfile.js');
//multer有single()中的名称必须是表单上传字段的name名称。
var upload=muilter.single('file');
function datainput(req, res) {
  upload(req, res, function (err) {
    //添加错误处理
    if (err) {
      return console.log(err);
    }
    //文件信息在req.file或者req.files中显示。
    let photopath = req.file.path;
    photopath = photopath.replace(/public/,"");//将文件路径中的public\去掉，否则会和静态资源配置冲突
    //将photopath存入数据库即可
    console.log(photopath);
    res.send(photopath);
  });
}
module.exports = {
  datainput
};

upload: function (e) {
    var that = this;
    let formdata = new window.formdata();
    let file = e.target.files[0];
    formdata.append('file',file);//通过append向form对象添加数据
    //利用split切割，拿到上传文件的格式
    var src = file.name,
     formart = src.split(".")[1];
    //使用if判断上传文件格式是否符合
    if (formart == "jpg" || formart == "png" ||
     formart == "docx" || formart == "txt" ||
     formart == "ppt" || formart == "xlsx" ||
     formart == "zip" || formart == "rar" ||
     formart == "doc") {
     //只有满足以上格式时，才会触发ajax请求
     this.$axios.post(this.$api.personalcenter.upfile,formdata).then(function (res) {
      that.upfiledata = res.data;
     }).then(function (res) {
      var params = {
       photos_url: that.upfiledata,
       photo_des: ''
      };
//      console.log(params.photos_url,'photos_url')
      that.$axios.post(that.$api.personalcenter.walladd,qs.stringify(params)).then(function (res) {
       console.log(res.data);
       that.$options.methods.imglist.bind(that)();
      }).catch(function (err) {
       console.log(err);
       console.log("请求出错");
      })
     })
    } else {
     alert("文件格式不支持上传");
    }
}