js代码

<script src="js/vue2.2.2.js"></script>
<script>
  //  import up from  './src/components/Hello'
  var app = new Vue({
    el: '#app',
    data () {
      return {
        imgList: [],
        size: 0
      }
    },
    methods: {
      fileClick(){
        document.getElementById('upload_file').click()
      },
      fileChange(el){
        if (!el.target.files[0].size) return;
        this.fileList(el.target.files);
        el.target.value = ''
      },
      fileList(files){
        for (let i = 0; i < files.length; i++) {
          this.fileAdd(files[i]);
        }
      },
      fileAdd(file){
        this.size = this.size + file.size;//总大小
        let reader = new FileReader();
        reader.vue = this;
        reader.readAsDataURL(file);
        reader.onload = function () {
          file.src = this.result;
          this.vue.imgList.push({
            file
          });
        }
      },
      fileDel(index){
        this.size = this.size - this.imgList[index].file.size;//总大小
        this.imgList.splice(index, 1);
      },
      bytesToSize(bytes){
        if (bytes === 0) return '0 B';
        let k = 1000, // or 1024
          sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
          i = Math.floor(Math.log(bytes) / Math.log(k));
        return (bytes / Math.pow(k, i)).toPrecision(3) + ' ' + sizes[i];
      },
      dragenter(el){
        el.stopPropagation();
        el.preventDefault();
      },
      dragover(el){
        el.stopPropagation();
        el.preventDefault();
      },
      drop(el){
        el.stopPropagation();
        el.preventDefault();
        this.fileList(el.dataTransfer.files);
      }
    }
  })
</script>