input实现图片或视频上传（样式+代码）

背景：vue/element.ui

 1..html：

<div v-show="recordForm.resourceType==1">
  <el-form-item>
    <ul class="img-list">
      <li v-for="(item,index) in recordForm.item">
        <img :src=item.resourceUrl alt="" :key="index"/>
        <span class="icon-btn">
            <i class="el-icon-remove-outline del-btn" @click="delImg($event)" :data-src="item.resourceUrl"></i>
          </span>
      </li>
      <li v-show="isLimit">
        <span class="btnfile">
          <input data-role="file" type="file" class="ufile" name="file"
                 id="uploadImgBtn" @change="upload" @click="clearValue($event)" :accept="accept">
          <i data-role="upBtn" class="upload-btn el-icon-plus" enctype="multipart/form-data"></i>
        </span>
      </li>
    </ul>
    <p class="little-tip">单个图片上传大小限制：10M</p>
    <p class="little-tip">图片数限制：1张至6张</p>
  </el-form-item>
</div>

注意

1. input标签的accept属性，设置上传图片的格式
2. input标签的multiple="multiple"，设置可否多选

2.css：

.img-list {
  padding: 0;
  overflow: hidden;
  li {
    position: relative;
    list-style: none;
    float: left;
    margin: 10px;
    .del-btn {
      position: absolute;
      top: 0;
      right: 0;
      color: transparent;
    }
    img {
      border-radius: 3px;
    }
    &:hover .del-btn {
      color: #000;
    }
  }
}
.little-tip {
  color: #c7c9d1;
}
.upload-video {
  position: relative;
  display: inline-block;
  border: 1px solid #cacdd4;
  padding: 0 15px;
  border-radius: 3px;
  background-color: #3f9dff;
  color: #fff;
  .videofile {
    position: absolute;
     100%;
    height: 100%;
    right: 0;
    top: 0;
    opacity: 0;
  }
}
3.upload.js

function upload(config) {
  this.config = config;
}

upload.prototype.ajaxUp = function (fileId, callback) {
  for (var i = 0; i < $('#' + fileId)[0].files.length; i++) {
    var formData = new FormData();
    formData.append('file_list', $('#' + fileId)[0].files[i].name);
    ajax({
      url: '验签url，如果不需要省略该ajax',
      type: 'POST',
      data: formData,
      async: false,
      dataType: 'json',
      index: i,
      success: function (data, cur_i) {
        if (0 === data.code) {
          var signs = data.data.signs;
          var policy = signs.Policy;
          var kss = signs.KSSAccessKeyId;
          var key = signs.key;
          var acl = signs.acl;
          var signature = signs.Signature;
          var name = signs.file_name;
          var formDataUp = new FormData();

          formDataUp.append('KSSAccessKeyId', kss);
          formDataUp.append('acl', acl);
          formDataUp.append('key', key);
          formDataUp.append('Policy', policy);
          formDataUp.append('Signature', signature);
          formDataUp.append('file', $('#' + fileId)[0].files[cur_i]);
          var fileObj = $('#' + fileId)[0].files[cur_i];
          ajax({
            url: '上传服务器url',
            type: 'POST',
            data: formDataUp,
            async: false,
            success: function () {
              callback(key, name, fileObj);
              window.console.log('upload class success');

            },
            error: function () {
              window.console.log('与提交服务器通信发生错误');
            }
          });
        }
      },
      error: function () {
        window.console.log('与获取服务器通信发生错误');
      }
    });
  }
};

4.js的使用

import Uploader from '@/libs/upload'

let uploader = new Uploader()
uploader.ajaxUp(containerId, (key, name, fileObj) => {
  let host = '上传服务器url'
  let url = host + key
  _this.process = '上传完成'
  _this.isDelAction = false
  obj.resourceUrl = url
  _this.recordForm.item.push(obj)
})

注意：

@change事件，上传时，如果连续上传同一张图片，则第二次不会再触发change事件

解决方法：同时给该input绑定click事件，清除该事件源e.target的value值，即e.target.value=''

原理：

1. 当input捕获到焦点后，系统储存当前值
2. 当input焦点离开后，判断当前值与之前存储的值是否不等，如果为true则触发onchange事件