效果展示：

代码：

      <label for="avatarUpload">
                            <div>
                                <img v-if="avatatImageUrl" :src="avatatImageUrl" class="avatar">
                                <img v-else src="../../assets/images/account/avatar-upload.png" class="w-150px h-150px cursor-pointer" alt="">
                            </div>
                        </label>
                        <input type="file" id='avatarUpload' hidden @change='aa'>

    const aa = (e)=>{

        console.log(e);
        const file = e.target.files[0]

        console.log(file);
       
将二级制文件数据流显示出来
        // // 文件预览
        const reader = new FileReader();
        reader.readAsDataURL(file)
        reader.onload=()=>{
            avatatImageUrl.value = reader.result

            console.log(avatatImageUrl.value);
            
        }
    }