vuejs 2组件base64映像未更新 [英] vuejs 2 component base64 image not updating

问题描述

我要实现的目标:
从jwt令牌受保护的源加载图像
服务器将图像返回为base64字符串，然后我将该字符串作为背景url加载到图像上

what i want to achieve:
load an image from jwt token protected source
the server return the image as base64 string and i'll load this string as background url on the image

父组件:

<template lang="html">
     <myImage v-for="photo in form.photos" :photo="photo" @delphoto="deleteImage"></myImage>
</template>

export default {
        components: {
            myImage,
        },
        data(){
            return {
                form: {
                    photos: [
                {
            id: 1,
            thumbnail: "logo1.png"
            },
                {
            id: 2,
            thumbnail: "logo2.png"
            },
                {
            id: 3,
            thumbnail: "logo3.png"
            },
                {
            id: 4,
            thumbnail: "logo4.png"
            },
            ]

                },

            }
        },
        methods: {
            deleteImage(myphoto)
            {
                this.form.photos.splice(this.form.photos.indexOf(myphoto), 1);
            }
        }
    }

myImage组件

<template>
        <div v-if="loaded" class="img">
            <img class="albumimg" :style="{ background: img}" :title="title">
            <p @click="delimage">delete</p>
        </div>
        <div v-else class="img">
            <img class="loading" style="background: url('/images/spinner.gif')">
        </div>
</template>
<script>
    export default {
        data(){
            return {
                img: null,
                loaded: false
            }
        },
        props: {
            photo: {
                required: true
            },
            title: {
                default: ''
            },
        },
        created() {
            this.imgurl()
        },
        methods: {
            delimage() {
              this.$emit('delphoto', this.photo)
            },
            imgurl() {
                this.$http.get("/api/images/" + this.photo.id).then(response => {
                    this.img = "url('" + response.data + "')"
                    this.loaded = true
                }, response => {
                });
            },
        }
    }
</script>

现在，如果我从form.photos数组中删除照片(拼接)，则总是删除最后一张图像. 当我删除绿色图像时

now if i delete a photo (splice) from the form.photos array always the last image get removed. when i remove the green image

蓝色图像消失

当我检查form.photos数组时，删除了正确的图像，只有myImage组件中的img数据属性仍然是前一个数组位置1的旧值.

when i check the form.photos array, the correct image was removed, only the img data attribute from myImage component is still the old value from the previous array position 1.

我能够通过在照相道具上添加手表并重新获取base64字符串来绕过此问题，该字符串对每个图像都会产生新的获取请求

i was able to bypass this issue by adding a watch on the photo prop and refetch the base64 string which cause a new get request for every image

watch: {
   photo: function (val) {
      this.imgurl()
   }
},

有什么方法可以删除数组项(子组件)并显示正确的结果，而无需再次在子组件中获取所有图像?

is there any way to remove an array item (child component) and display the correct result without fetching all images again within the child component?

谢谢

推荐答案

尝试一下.

<myImage v-for="photo in form.photos" :key="photo.id" :photo="photo" @delphoto="deleteImage"></myImage>

根据当前的文档.

在2.2.0+中，将v-for用于组件时，现在需要密钥.

In 2.2.0+, when using v-for with a component, a key is now required.

这篇关于vuejs 2组件base64映像未更新的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！