let detailPath = `../views/CardDetail/${item.id}`;这句话写的多么

这句话是使用了模板字符串（template literals）的语法，可以方便地将变量值嵌入到字符串中。

在这句话中，模板字符串使用反引号（`）括起来。${item.id} 是一个占位符，表示要将 item 对象的 id 属性插入到字符串中。最终生成的字符串会被赋值给变量 detailPath。

如果不使用模板字符串，可能需要使用字符串拼接操作，比如：

let detailPath = '../views/CardDetail/' + item.id;

使用模板字符串可以使代码更简洁、更易读。

相关问题

<template> <van-pull-refresh v-model="refreshing" @refresh="onRefresh"> <van-list v-model:loading="loading" :finished="finished" finished-text="没有更多了" @load="onLoad"> <!-- <van-cell v-for="item in courses" :key="item" :title="item.title" /> --> <van-card v-for="item in courses" :key="item" num="2" price="2.00" :desc="item.body" :title="item.id + '-' + item.title" thumb="https://fastly.jsdelivr.net/npm/@vant/assets/ipad.jpeg" @click="ToCardDetail(item)"/> <template slots="loading"> <van-loading class="load-more-loading" /> <span class="load-more-text">加载中...</span> </template> </van-list> </van-pull-refresh> </template> <script> export default { name: "LoadMore", data() { return { list: [], courses: [], loading: false, finished: false, refreshing: false }; }, methods: { onLoad() { setTimeout(() => { if (this.refreshing) { this.courses = []; this.refreshing = false; } for (let i = 0; i < 10; i++) { this.courses.push(this.list[this.courses.length]); } this.loading = false; if (this.courses.length >= 40) { this.finished = true; } }, 3000); }, onRefresh() { // 清空列表数据 this.finished = false; // 重新加载数据 // 将 loading 设置为 true，表示处于加载状态 this.loading = true; this.onLoad(); }, ToCardDetail(item) { // 获取详情页的路由地址，例如：/detail/1 let detailPath = ../views/CardDetail/${item.id}; // 跳转到详情页 this.$router.push(detailPath); } }, created() { let url = "http://jsonplaceholder.typicode.com/posts" this.axios.get(url).then((res) => { this.list = res.data }) } }; </script> <style scoped> .load-more-loading { margin-right: 6px; } .load-more-text { font-size: 14px; color: #999; } </style>card详情页carddetail的代码怎么写

你可以新建一个名为CardDetail的.vue文件，然后在该文件中编写详情页的代码，如下所示：

<template>
<div class="card-detail">
<van-card :title="cardTitle" :thumb="cardThumb">
<div class="card-description">{{ cardDescription }}</div>
</van-card>
</div>
</template>

<script>
export default {
name: "CardDetail",
data() {
return {
cardId: "",
cardTitle: "",
cardThumb: "",
cardDescription: "",
};
},
created() {
this.cardId = this.$route.params.id;
// 根据id获取卡片详情数据
let url = `http://jsonplaceholder.typicode.com/posts/${this.cardId}`;
this.axios.get(url).then((res) => {
this.cardTitle = `${res.data.id}-${res.data.title}`;
this.cardThumb = "https://fastly.jsdelivr.net/npm/@vant/assets/ipad.jpeg";
this.cardDescription = res.data.body;
});
},
};
</script>

<style scoped>
.card-detail {
padding: 20px;
}
.card-description {
margin-top: 20px;
}
</style>

在上述代码中，我们通过 $route.params.id 获取到路由中的卡片id，并根据此id获取卡片的详情数据。最后在页面中展示卡片的标题、缩略图和描述信息。注意，需要在该组件中引入 vant 的 Card 组件。

private async parseMaterial(osgStateSet: any) { let material = new THREE.MeshBasicMaterial({ // side: THREE.DoubleSide, }); //THREE.FrontSide 背面 // THREE.BackSide 前面 // THREE.DoubleSide 双面 let osgImage = osgStateSet.TextureAttributeList[0].value.StateAttribute.Image; // let texture = this.parseImage(osgImage); let fileName = osgImage.Name; const isJPEG = fileName.search(/.jpe?g($|?)/i) > 0; const isPNG = fileName.search(/.png($|?)/i) > 0; if (!isPNG && !isJPEG) { return; } let mimeType = isPNG ? 'image/png' : 'image/jpeg'; let imageUri: any = new Blob([osgImage.Data], { type: mimeType }); let base64 = await this.blobToBase64(imageUri); // debugger let imageUrl: any = URL.createObjectURL(imageUri); try { let texture = new THREE.TextureLoader().load(base64, () => { texture.needsUpdate = true; // texture.format = THREE.RGBAFormat; texture.type = THREE.UnsignedShort5551Type; texture.minFilter = THREE.LinearMipmapNearestFilter; texture.magFilter = THREE.LinearMipmapNearestFilter; texture.generateMipmaps = false; // texture.format = THREE.RGBAIntegerFormat; // texture.minFilter = THREE.NearestFilter; // texture.magFilter = THREE.NearestFilter; // texture.minFilter = THREE.LinearMipMapLinearFilter; // texture.magFilter = THREE.LinearFilter; // texture.wrapS = THREE.RepeatWrapping; // texture.wrapT = THREE.RepeatWrapping; // texture.anisotropy = 1; // texture.generateMipmaps = false; // texture.encoding = THREE.sRGBEncoding; }); imageUri = null; osgImage = null; imageUrl = null; if (texture) { material.map = texture; } } catch (e) { console.log('纹理加载出错', e); } osgStateSet = null; return material; } private blobToBase64(blob: any) { return new Promise((resolve, reject) => { const fileReader = new FileReader(); // readAsDataURL fileReader.readAsDataURL(blob); fileReader.onload = (e: any) => { resolve(e.target.result); }; }); }没有显示base64图片的纹理，也没有报错，请找出问题，并给出详细代码

在代码中，你使用了一个Blob对象来加载纹理图片，并将其转换成了base64编码，但是在加载纹理时，却直接使用了base64编码字符串来加载纹理，这个可能是导致问题的原因。正确的做法应该是使用图片的URL来加载纹理，而不是直接使用base64编码字符串。

具体修改代码如下：

private async parseMaterial(osgStateSet: any) {
    let material = new THREE.MeshBasicMaterial({
        // side: THREE.DoubleSide,
    });
    //THREE.FrontSide 背面
    // THREE.BackSide 前面
    // THREE.DoubleSide 双面

    let osgImage = osgStateSet.TextureAttributeList[0].value.StateAttribute.Image;
    // let texture = this.parseImage(osgImage);

    let fileName = osgImage.Name;
    const isJPEG = fileName.search(/.jpe?g($|?)/i) > 0;
    const isPNG = fileName.search(/.png($|?)/i) > 0;
    if (!isPNG && !isJPEG) {
        return;
    }
    let mimeType = isPNG ? 'image/png' : 'image/jpeg';
    let imageUri: any = new Blob([osgImage.Data], { type: mimeType });

    try {
        // 使用图片的URL来加载纹理
        let texture = await new Promise<THREE.Texture>((resolve) => {
            let imageUrl = URL.createObjectURL(imageUri);
            new THREE.TextureLoader().load(imageUrl, (texture) => {
                // 在加载完成的回调函数中，手动释放URL对象，避免内存泄漏问题
                URL.revokeObjectURL(imageUrl);
                texture.needsUpdate = true;
                // texture.format = THREE.RGBAFormat;
                texture.type = THREE.UnsignedShort5551Type;
                texture.minFilter = THREE.LinearMipmapNearestFilter;
                texture.magFilter = THREE.LinearMipmapNearestFilter;
                texture.generateMipmaps = false;
                // texture.format = THREE.RGBAIntegerFormat;
                // texture.minFilter = THREE.NearestFilter;
                // texture.magFilter = THREE.NearestFilter;
                // texture.minFilter = THREE.LinearMipMapLinearFilter;
                // texture.magFilter = THREE.LinearFilter;
                // texture.wrapS = THREE.RepeatWrapping;
                // texture.wrapT = THREE.RepeatWrapping;
                // texture.anisotropy = 1;
                // texture.generateMipmaps = false;
                // texture.encoding = THREE.sRGBEncoding;
                resolve(texture);
            });
        });

        if (texture) {
            material.map = texture;
        }
    } catch (e) {
        console.log('纹理加载出错', e);
    }
    osgStateSet = null;
    return material;
}

private blobToBase64(blob: any) {
    return new Promise((resolve, reject) => {
        const fileReader = new FileReader();
        // readAsDataURL
        fileReader.readAsDataURL(blob);
        fileReader.onload = (e: any) => {
            resolve(e.target.result);
        };
    });
}

其中，使用了一个Promise对象来等待纹理加载完成后返回，同时在加载完成的回调函数中，手动释放URL对象，避免内存泄漏问题。另外，建议在加载纹理时，设置合适的minFilter和magFilter，以获得更好的渲染效果。