<template>
  <div>
    <div class="demo-upload-list" v-for="(item,index) in uploadList" :key='index'>
      ![](item.url)
      <div class="demo-upload-list-cover">
        <Icon type="ios-trash-outline" @click.native="handleRemove(item)"></Icon>
      </div>
    </div>
    <Upload ref="upload" :show-upload-list="false" :format="['jpg','jpeg','png']" :max-size="2048" :before-upload="handleBeforeUpload" :on-format-error="handleFormatError" :on-exceeded-size="handleMaxSize" type="drag" action="//jsonplaceholder.typicode.com/posts/" style="display: inline-block;width:58px;">
      <div style="width: 58px;height:58px;line-height: 58px;">
        <Icon type="camera" size="20"></Icon>
      </div>
    </Upload>
  </div>
</template>
<script>
export default {
  methods: {
    data () {
      return {
        uploadList: []
      }
    },
    handleBeforeUpload (file) {
    // 创建一个 FileReader 对象
      let reader = new FileReader()
      // readAsDataURL 方法用于读取指定 Blob 或 File 的内容
      // 当读操作完成，readyState 变为 DONE，loadend 被触发，此时 result 属性包含数据：URL（以 base64 编码的字符串表示文件的数据）
      // 读取文件作为 URL 可访问地址
      reader.readAsDataURL(file)

      const _this = this
      reader.onloadend = function (e) {
        file.url = reader.result
        console.log(file.url)
        this.$emit('imgSrc', file.url)

        _this.uploadList.push(file)
      }
    },
    handleRemove (file) {
      this.uploadList.splice(this.uploadList.indexOf(file), 1)
    },
    handleFormatError (file) {
      this.$Notice.warning({
        title: '文件格式不正确',
        desc: '文件 ' + file.name + ' 格式不正确，请上传 jpg 或 png 格式的图片。'
      })
    },
    handleMaxSize (file) {
      this.$Notice.warning({
        title: '超出文件大小限制',
        desc: '文件 ' + file.name + ' 太大，不能超过 2M。'
      })
    }
  }
}
</script>
<style scoped>
.demo-upload-list {
  display: inline-block;
  width: 60px;
  height: 60px;
  text-align: center;
  line-height: 60px;
  border: 1px solid transparent;
  border-radius: 4px;
  overflow: hidden;
  background: #fff;
  position: relative;
  box-shadow: 0 1px 1px rgba(0, 0, 0, .2);
  margin-right: 4px;
}

.demo-upload-list img {
  width: 100%;
  height: 100%;
}

.demo-upload-list-cover {
  display: none;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, .6);
}

.demo-upload-list:hover .demo-upload-list-cover {
  display: block;
}

.demo-upload-list-cover i {
  color: #fff;
  font-size: 20px;
  cursor: pointer;
  margin: 0 2px;
}

.ivu-icon {
  line-height: 58px;
}
</style>
