javascript - 如何在 .js 幻灯片中交叉淡入淡出图像

Question

这是我的幻灯片 div:

<div class="header">
    <img name="slide" class="slide">
</div>

它的CSS:

.slide{
    width: 80%;
    height: auto;
    filter: brightness(90%);
}

和 JavaScript:

var i = 0;
var images = [];
var time = 4000;


images[0] = '1.png';
images[1] = '2.png';
images[2] = '3.png';

function changeImg() {
  document.slide.src = images[i];

  if (i < images.length -1) {
    i++;

  }
  else
  {
    i = 0;
  }


  setTimeout("changeImg()", time);

}

window.onload = changeImg;

现在我希望它交叉淡入淡出，目前它只是非常突然地切换图像，但我希望它平滑。有什么帮助吗？

Answer 1

您需要在 css 类上添加不透明度设置为 0 的内容，然后创建一个不透明度设置为 1 的新类，这样您将在经过特定时间段后触发切换不透明度的函数

<style>
    .slide {
        border: none; 
        opacity: 0; 
        position: absolute; 
        top: 0; 
        left: 0;
        -webkit-transition: opacity 2s linear;
        -moz-transition: opacity 2s linear;
        -o-transition: opacity 2s linear;
        transition: opacity 2s linear;
    }
    .visible {
        opacity: 1;
    }
</style>

<div class="header">
    <img id="img0" class="slide visible" src="1.png">
    <img id="img1" class="slide" src="2.png">
    <img id="img2" class="slide" src="3.png">
</div>

<script>
    var actual = 0;
    var total = 3;

    function addClass(elem, name) {
        elem.className = elem.className + " " + name;
    }

    function deleteClass(elem, name) {
        var c = elem.className;
        elem.className = c.replace(name, "").replace(/   /g, " ").replace(/^ | $/g, "");
    }

    function nextImg() {
        var e;

        e = document.getElementById("img" + actual);
        deleteClass(e, "visible");

        actual++;
        if (actual > total - 1) actual = 0;

        e = document.getElementById("img" + actual);
        addClass(e, "visible");
    }

    var slider = setInterval(nextImg, 4000);
</script>