Vue + Node.js + MongoDB图片上传组件实现图片预览和删除功能详解

目录

• 功能
• 目录结构
• node.js写后端

<form class="upload-content-right-top" enctype="multipart/form-data" ref="formSubmit" >
  <label class="upload-content-right-top-btn">上传图片</label>
  <input type="file" @change="uploadImage($event)" multiple="multiple" accept="image/gif, image/jpeg, image/png">
</form>
<iframe id="rfFrame" name="rfFrame" src="about:blank" style="display:none;"></iframe>

upload();
document.forms[0].target="rfFrame";

  let count = 0;//上传函数外定义变量，记录文件的数量，即递归的次数
/*-----------------------此段代码在上传函数中-------------------------------*/
  let fileReader = new FileReader();
  //解析图片路径，实现预览
  fileReader.readAsDataURL(file.files[count]);
  fileReader.onload=()=>{
   previewData = {
     url:fileReader.result,//图片预览的img标签的src
     name:file.files[count].name,
     size:file.files[count].size,
   };
   //这段代码在上传函数中，所以在外面定义了一个_this = this，fileList为vue的data中定义的状态
  _this.fileList.push(previewData);
  };

let progress = 0;
let config = {
 headers: {'Content-Type': 'multipart/form-data'},
 onUploadProgress (progressEvent){
  if(progressEvent.lengthComputable){
   progress = progressEvent.total/progressEvent.loaded;
   _this.$refs.progress[_this.$refs.progress.length-1].style.width = Number(progress).toFixed(2)*100+"%";
  }
 }
};

formData = new FormData();
if(file.files[count]){
formData.append('file',file.files[count],file.files[count].name);

let file=$event.target,
formData = new FormData();
//递归调用自身，实现多文件依次上传
let _this = this;
let count = 0;
let previewData = {};
uploadImage($event){
   let file=$event.target,
   formData = new FormData();
   //递归调用自身，实现多文件依次上传
   let _this = this;
   let count = 0;
   let previewData = {};
   function upload(){
    //开始上传时，滚到底部
    _this.$refs.picWrapper.scrollTop = _this.$refs.picWrapper.scrollHeight;
    //定义axios配置信息
    let progress = 0;
    let config = {
     headers: {'Content-Type': 'multipart/form-data'},
     onUploadProgress (progressEvent){
      console.log(`进度条的数量${_this.$refs.progress.length -1}`);
      if(progressEvent.lengthComputable){
       progress = progressEvent.total/progressEvent.loaded;
       //进度条
       _this.$refs.progress[_this.$refs.progress.length-1].style.width = Number(progress).toFixed(2)*100+"%";
      }
     }
    };
    //向formData中插入文件
    if(file.files[count]){
    formData.append('file',file.files[count],file.files[count].name);
    let fileReader = new FileReader();
    //解析图片路径，实现预览
    fileReader.readAsDataURL(file.files[count]);
    fileReader.onload=()=>{
     previewData = {
      url:fileReader.result,
      name:file.files[count].name,
      size:file.files[count].size,
     };
     _this.fileList.push(previewData);
     _this.progressShow = true
    };
    fileReader.onloadend=()=>{
     //检测图片大小是否超出限制
     if(formData.get('file').size>_this.maxSize){
      formData.delete('file');
      //当图片全部上传完毕，停止递归
      count++;
      if(count > file.files.length-1){
       return
      }
      upload()
     }else{
       //发送数据
       axios.post(`/upload?mark=${_this.group}`,formData,config).then((response)=>{
        formData.delete('file');
        let res = response.data;
        console.log(res);
        if(res.result){
         //如果是新建上传
         if(_this.group === 'new'){
          _this.fileList.push(res.data);
           _this.fileList.forEach((item,index)=>{
             if(!item.newName){
              _this.fileList.splice(index,1)
             }
           })
          }else{
          //如果是选择其他组上传，直接把返回数据赋值到文件数组
           _this.fileList = res.data;
          }
         _this.newUpload = false
        }else{
         alert('上传失败');
         return;
        }
        _this.noPic = false;
        count++;
        if(count > file.files.length-1){
         return
        }
        upload()
       }).catch((err)=>{
        alert('上传失败123');
       });
      }
    };
    }
   }
   //第一次调用
   upload();
   document.forms[0].target="rfFrame";
}

//引入表单处理模块
let Formidable = require("formidable");

form.encoding = 'utf-8';
form.uploadDir = '/project/vue/vue_uploader/my-server/public/images';//定义文件存放地址
form.keepExtensions = true;
form.multiples = false;//以单文件依次上传的方式，实现多文件上传
form.maxFieldsSize = 1*1024;
//解析图片，重命名图片名称，返回给前端。
let fileData = "";
let fileDir = "images";//定义文件的存放路径
let route = 'upload_';//定义路由
let serverIp = 'http://localhost:3002/';//定义服务器IP

function handleFile (file){
  let filename = file.name;
  let nameArray = filename.split('.');
  let type = nameArray[nameArray.length-1];
  let name = '';
  for (let i = 0;i<nameArray.length - 1;i++){
    name = name + nameArray[i];
  }
  let date = new Date();
  let time = '_' + date.getFullYear() + "_" + date.getMonth() + "_" + date.getDay() + "_" + date.getHours() + "_" + date.getMinutes() +"_"+ date.getSeconds()+"_"+date.getMilliseconds();
  let picName = name + time + '.' + type;
  let newPath = form.uploadDir + "/" + picName;
  let oldPath = form.uploadDir + "/"+ file.path.substring(file.path.indexOf(route));
  fs.renameSync(oldPath, newPath); //重命名
  fileData = {
    id:`${new Date().getTime()}`,
    url:serverIp + newPath.substring(newPath.indexOf(fileDir)),
    name:file.name,
    size:file.size,
    isSelected:false,
    newName:picName,
  };
  UploadData.findOne({group:group},(err,doc)=>{
    if(err){
      res.json({
        result:false,
        msg:err.message
      })
    }else{
      if(doc){
        doc.picList.push(fileData);
        doc.save((err,saveResult)=>{
          if(err){
            return res.json({
              result:false,
            });
          }else{
            let length= doc.picList.length;
            console.log(doc.picList.length)
            if(groupMark === 'all'){
              UploadData.find({},(err,queryResult)=>{
                if(err){
                  res.json({
                    result:false,
                    mgs:'发生错误了'
                  })
                }else{
                  let allPic = [];
                  queryResult.forEach((item)=>{
                    if(item.group !=='default'){
                      allPic = allPic.concat(item.picList)
                    }
                  });
                    res.json({
                      result:true,
                      data:allPic.concat(queryResult[1].picList)
                    })
                }
              })
            }else if(groupMark === 'new'){
              UploadData.findOne({group:'default'},(err,queryResult)=>{
                if(err){
                  return res.json({
                    result:false,
                    msg:err.message
                  });
                }else{
                  return res.json({
                    result:true,
                    data:queryResult.picList[queryResult.picList.length-1]
                  })
                }
              });
            }else{
              UploadData.findOne({group:group},(err,queryResult)=>{
                if(err){
                  return res.json({
                    result:false,
                    msg:err.message
                  });
                }else{
                  return res.json({
                    result:true,
                    data:queryResult.picList
                  })
                }
              });
            }
          }
        })
      }
    }
  })
}

form.parse(req,(err,fields,files)=>{
  //传多个文件
  if(files.file instanceof Array){
    return
  }else{
   //传单个文件
    handleFile(files.file)
  }
});