主页 / 问题 / 903570
Accepted
Malyuga
Asked:2020-11-08 00:36:01 +0000 UTC2020-11-08 00:36:01 +0000 UTC

无法读取未定义的属性“样式”

  • 772

我正在制作一个滑块，但出现错误。首先，它不起作用，其次，其中一个按钮不起作用。出现“Cannot read property 'style' of undefined”错误。代码：

var slide = document.getElementById('slider_ul');
var slides = slide.getElementsByTagName('li');  
var currentSlide = 0;


function leftBtn() {
   slides[currentSlide].style.display = 'none';
   currentSlide = (++currentSlide)%slides.length;
   slides[currentSlide].style.display = 'block';
}

function rightBtn() {
   slides[currentSlide].style.display = 'none';
   currentSlide = (--currentSlide)%slides.length;
   slides[currentSlide].style.display = 'block';
}

该错误恰好发生在 rightBtn 函数上。谢谢！

javascript

1 个回答

  1. Best Answer

    为什么它不起作用：

    var a = -1;
var b = 3;
console.log(a, "%", b, "=", a % b);

    如何：

    var slide = document.getElementById('slider_ul');
var slides = slide.querySelectorAll('li');  
var currentSlide = 0;

function leftBtn() {
   slides[currentSlide].style.display = 'none';
   currentSlide = (++currentSlide) % slides.length;
   slides[currentSlide].style.display = '';
}

function rightBtn() {
   slides[currentSlide].style.display = 'none';
   currentSlide = (--currentSlide + slides.length) % slides.length;
   slides[currentSlide].style.display = '';
}
    <ul id="slider_ul">
<li>First</li>
<li style="display:none">Second</li>
<li style="display:none">Third</li>
</ul>

<button type="button" onclick="rightBtn()">Previous</button>
<button type="button" onclick="leftBtn()">Next</button>

    • 2

相关问题