我偶然发现了一个似乎无法解决的问题。我试图在此处搜索解决方案，但无法自救。我是javascript的新手，请多加注意。
问题： 我正在将带有样式化jsx的nextjs（6.1.2）与react（16.5.0）一起使用：
import React, {Component} from 'react';
import PropTypes from 'prop-types';
import Link from 'next/link';
class ProductCard extends Component {
constructor(props) {
super(props);
this.state = {imgLoaded: false};
this.imgHasLoaded = this.imgHasLoaded.bind(this);
}
imgHasLoaded() {
this.setState({imgLoaded:true})
}
render() {
return (
<div className="thumbnail-container">
<div className="loader-box">
<img src={require("../static/loading.png")} className="loading-img" />
</div>
<img src={this.props.imgSrc} className="main-img" onLoad={this.imgHasLoaded} />
<div className="thumbnail-text">
{this.props.text}
</div>
<ul className="item-list">
{this.props.links.map(link =>
<li className="item">
<span className="item-span"> {link.text} </span>
{link.subLinks &&
<ul className="sub-item-list">
{link.subLinks.map(subLink => <li>{subLink.text}</li>)}
</ul>
}
</li>
)}
</ul>
<style jsx> {`
.thumbnail-container {
user-select: none;
position: relative;
text-align: center;
width: 98%;
height: 98%;
margin: 1%;
display: block;
border: 0.3px solid black;
overflow: hidden;
border-radius: 10px;
box-shadow: 0 0 20px 0px rgba(0, 0, 0, 0.5);
overflow: hidden;
align-items: center;
}
.thumbnail-text {
position: absolute;
width: 100%;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
color: #ffffff;
font-size: 1.8em;
background-color: #333;
padding: 5px;
border-radius: 5px;
text-shadow: 1px 1px #000000;
text-transform: uppercase;
box-shadow: 0 5px 10px 0px rgba(0, 0, 0, 1);
transition: all 0.2s ease;
}
.thumbnail-container:hover .thumbnail-text, .thumbnail-container:focus .thumbnail-text, .thumbnail-container:active .thumbnail-text {
top: 0;
transform: translate(-50%, 0);
background-color: rgba(255, 124, 4, 0.9);
color: #000000;
text-shadow: none;
}
.main-img {
width: 100%;
height: 100%;
border-radius: 8px;
margin: auto;
-webkit-filter: grayscale(40%) contrast(120%) brightness(110%) saturate(120%);
-moz-filter: grayscale(40%) contrast(120%) brightness(110%) saturate(120%);
filter: grayscale(40%) contrast(120%) brightness(110%) saturate(120%);
opacity: ${this.state.imgLoaded ? 1 : 0};
}
.thumbnail-container:hover .main-img, .thumbnail-container:focus .main-img, .thumbnail-container:active .main-img{
-webkit-filter: grayscale(40%) contrast(120%) saturate(120%) brightness(30%);
-moz-filter: grayscale(40%) contrast(120%) saturate(120%) brightness(30%);
filter: grayscale(40%) contrast(120%) saturate(120%) brightness(30%);
}
.item-list {
display: none;
position: absolute;
bottom: 0;
left: 0;
height: calc(100% - 2em);
flex-flow: column wrap;
justify-content: space-around;
list-style-type: none;
}
.thumbnail-container:hover .item-list, .thumbnail-container:focus .item-list, .thumbnail-container:active .item-list{
display: flex;
}
.item {
font-size: 1.3em;
display: flex;
flex-flow: column wrap;
}
.item-span {
padding-left: 8px;
border-bottom: solid #ff7c04;
border-left: solid #ff7c04;
transition: border-bottom 0.2s ease;
}
.item:hover .item-span, .item:focus .item-span, .item:active .item-span{
border-bottom: none;
}
.sub-item-list {
margin-left: 8px;
margin-top: 8px;
border-bottom: solid #ff7c04;
border-left: solid #ff7c04;
height: auto;
flex: 0;
overflow: hidden;
transition: flex 0.2s ease;
}
.item:hover .sub-item-list, .item:focus .sub-item-list, .item:active .sub-item-list{
flex: 1;
}
.loader-box {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
width: 48px;
height: 48px;
}
.loading-img {
-webkit-animation: rotate-scale-up 1s linear infinite both;
animation: rotate-scale-up 1s linear infinite both;
}
@-webkit-keyframes rotate-scale-up {
0% {
-webkit-transform: scale(1) rotateZ(0);
transform: scale(1) rotateZ(0);
}
50% {
-webkit-transform: scale(1.5) rotateZ(180deg);
transform: scale(1.5) rotateZ(180deg);
}
100% {
-webkit-transform: scale(1) rotateZ(360deg);
transform: scale(1) rotateZ(360deg);
}
}
@keyframes rotate-scale-up {
0% {
-webkit-transform: scale(1) rotateZ(0);
transform: scale(1) rotateZ(0);
}
50% {
-webkit-transform: scale(1.5) rotateZ(180deg);
transform: scale(1.5) rotateZ(180deg);
}
100% {
-webkit-transform: scale(1) rotateZ(360deg);
transform: scale(1) rotateZ(360deg);
}
}
a {
text-decoration: none;
}
@media only screen and (max-width: 700px) {
.thumbnail-container {
width: 96%;
height: 96%;
margin: 2%;
}
.thumbnail-text {
height: 1.5em;
font-size: 1em !important;
}
.item-list {
height: calc(100% - 3em) !important;
}
}
`}
</style>
</div>
);
}
}
但是，当使用上面的代码时，我在第26行（其中“ item-list”开始的地方）的渲染函数中得到了“ “无法读取未定义的属性'state'”” 。问题与使用
有关 opacity: ${this.state.imgLoaded ? 1 : 0};
在styled-jsx中，因为如果没有这一行，代码将运行良好。
有趣的是，如果删除“ item-list”及其内容，即使使用
opacity: ${this.state.imgLoaded ? 1 : 0};
很抱歉，这是一件微不足道的事情，或者/并且我忘记了一些基本问题。请按正确的方向推动我
答案 0 :(得分：0)
好的，我发现我的问题与此处描述的样式化jsx问题有关：
https://github.com/zeit/styled-jsx/issues/486
临时的解决方法是将imgLoaded拉入var，然后在样式化jsx中使用它。