vue+element-ui实现编辑图片预览

1，下载图片预览返回的是二进制的字节流，如何与img标签中的src属性绑定，查看图片呢？

 2.接口中加上响应类型:       responseType: 'blob'

export function downloadFile(fileId) {
    return service.request({
        method: 'get',
        url: `/file/download/${fileId}`,
        responseType: 'blob'
    })
}

3.URL.createObjectURL(下载接口中返回的二进制流)

        async getDeta(id){
          console.log(id)
            this.modDialogVisible  = true
            const res = await getBannerDeta({bannerId:id})
            this.deta = res.data
            this.modInfo.attachment.attachId = this.deta.attachment.attachId
            this.modInfo.bannerId = id
            this.modInfo.bannerState = res.data.bannerState
            this.modInfo.bannerTitle = res.data.bannerTitle
            var fileId= res.data.attachment.url
            const res1 = await downloadFile(fileId)
            this.modurl  = URL.createObjectURL(res1);
        },

4.src绑定

if="modurl" :src="modurl" class="avatar">