如何使javascript slider自动滑动

Question

**İt 只能通过单击来工作，但我也希望它自动滑动并同时单击。 **

 var slideIndex = 1; showSlides(slideIndex); function plusSlides(n) { showSlides(slideIndex += n); } function currentSlide(n) { showSlides(slideIndex = n); } function showSlides(n) { var i; var slides = document.getElementsByClassName("slider-item"); var dots = document.getElementsByClassName("dot"); if (n > slides.length) {slideIndex = 1} if (n < 1) {slideIndex = slides.length} for (i = 0; i < slides.length; i++) { slides[i].style.display = "none"; } for (i = 0; i < dots.length; i++) { dots[i].className = dots[i].className.replace(" active", ""); } slides[slideIndex-1].style.display = "block"; dots[slideIndex-1].className += " active"; }

Answer 1

从我搜索的内容来看，这是来自w3schools的 how to-slideshow ，您只需要在底部添加setInterval

timeout = setInterval(() => {
    plusSlides(1)
}, 2000); // Change image every 2 seconds

 var slideIndex = 1; var timeout; showSlides(slideIndex); function plusSlides(n) { showSlides(slideIndex += n); } function currentSlide(n) { showSlides(slideIndex = n); } function showSlides(n) { var i; var slides = document.getElementsByClassName("mySlides"); var dots = document.getElementsByClassName("dot"); if (n > slides.length) { slideIndex = 1 } if (n < 1) { slideIndex = slides.length } for (i = 0; i < slides.length; i++) { slides[i].style.display = "none"; } for (i = 0; i < dots.length; i++) { dots[i].className = dots[i].className.replace(" active", ""); } slides[slideIndex - 1].style.display = "block"; dots[slideIndex - 1].className += " active"; } timeout = setInterval(() => { plusSlides(1) }, 2000); // Change image every 2 seconds

 * {box-sizing: border-box} body {font-family: Verdana, sans-serif; margin:0}.mySlides {display: none} img {vertical-align: middle;} /* Slideshow container */.slideshow-container { max-width: 1000px; position: relative; margin: auto; } /* Next & previous buttons */.prev, .next { cursor: pointer; position: absolute; top: 50%; width: auto; padding: 16px; margin-top: -22px; color: white; font-weight: bold; font-size: 18px; transition: 0.6s ease; border-radius: 0 3px 3px 0; user-select: none; } /* Position the "next button" to the right */.next { right: 0; border-radius: 3px 0 0 3px; } /* On hover, add a black background color with a little bit see-through */.prev:hover, .next:hover { background-color: rgba(0,0,0,0.8); } /* Caption text */.text { color: #f2f2f2; font-size: 15px; padding: 8px 12px; position: absolute; bottom: 8px; width: 100%; text-align: center; } /* Number text (1/3 etc) */.numbertext { color: #f2f2f2; font-size: 12px; padding: 8px 12px; position: absolute; top: 0; } /* The dots/bullets/indicators */.dot { cursor: pointer; height: 15px; width: 15px; margin: 0 2px; background-color: #bbb; border-radius: 50%; display: inline-block; transition: background-color 0.6s ease; }.active, .dot:hover { background-color: #717171; } /* Fading animation */.fade { -webkit-animation-name: fade; -webkit-animation-duration: 1.5s; animation-name: fade; animation-duration: 1.5s; } @-webkit-keyframes fade { from {opacity: .4} to {opacity: 1} } @keyframes fade { from {opacity: .4} to {opacity: 1} } /* On smaller screens, decrease text size */ @media only screen and (max-width: 300px) {.prev, .next,.text {font-size: 11px} }

 <div class="slideshow-container"> <div class="mySlides fade"> <div class="numbertext">1 / 3</div> <img src="https://www.w3schools.com/howto/img_nature_wide.jpg" style="width:100%"> <div class="text">Caption Text</div> </div> <div class="mySlides fade"> <div class="numbertext">2 / 3</div> <img src="https://www.w3schools.com/howto/img_snow_wide.jpg" style="width:100%"> <div class="text">Caption Two</div> </div> <div class="mySlides fade"> <div class="numbertext">3 / 3</div> <img src="https://www.w3schools.com/howto/img_mountains_wide.jpg" style="width:100%"> <div class="text">Caption Three</div> </div> <a class="prev" onclick="plusSlides(-1)">&#10094;</a> <a class="next" onclick="plusSlides(1)">&#10095;</a> </div> <br> <div style="text-align:center"> <span class="dot" onclick="currentSlide(1)"></span> <span class="dot" onclick="currentSlide(2)"></span> <span class="dot" onclick="currentSlide(3)"></span> </div>