如何使用 CSS 和 JavaScript 创建缩放图像?
cssjavascriptweb developmentfront end technology
以下是创建图像缩放的代码:
示例
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
* {box-sizing: border-box;}
.img{
display: inline-block;
}
.img-zoom-container {
position: relative;
}
.img-zoom-zoomLens {
position: absolute;
border: 1px solid #d4d4d4;
width: 50px;
height: 50px;
}
.myresult{
display: inline-block;
}
.img-zoom-result {
border: 1px solid #d4d4d4;
}
</style>
</head>
<body>
<h1>Image Zoom Example</h1>
<div class="img-zoom-container">
<img class="myimage" src="https://i.picsum.photos/id/1015/536/354.jpg?hmac=x7KEhPoOftwPXIgnQoTQzNtVUqaPYwndK8n1x_9rWuM" style="width: 400px; height: 400px;">
<div class="myresult" class="img-zoom-result" style="width: 400px;height: 400px;"></div>
</div>
<h1>Hover over the image on the left to see it zoomed on right</h1>
<script>
let imageEle = document.querySelector('.myimage');
let resultEle = document.querySelector('.myresult');
enlargeImage(imageEle, resultEle);
function enlargeImage(imgEle, resultEle) {
var zoomLens, xPos, yPos;
zoomLens = document.createElement("DIV");
zoomLens.setAttribute("class", "img-zoom-zoomLens");
imgEle.parentElement.insertBefore(zoomLens, imgEle);
xPos = resultEle.offsetWidth / zoomLens.offsetWidth;
yPos = resultEle.offsetHeight / zoomLens.offsetHeight;
resultEle.style.backgroundImage = `url(${imgEle.src})`;
resultEle.style.backgroundSize = (imgEle.width * xPos) + "px " + (imgEle.height * yPos) + "px";
zoomLens.addEventListener("mousemove", lensMoveCalculate);
imgEle.addEventListener("mousemove", lensMoveCalculate);
zoomLens.addEventListener("touchmove", lensMoveCalculate);
imgEle.addEventListener("touchmove", lensMoveCalculate);
function lensMoveCalculate(e) {
var pos, x, y;
pos = currentCursonPos(e);
x = pos.x - (zoomLens.offsetWidth / 2);
y = pos.y - (zoomLens.offsetHeight / 2);
if (x > imgEle.width - zoomLens.offsetWidth) {x = imgEle.width - zoomLens.offsetWidth;}
if (x < 0) {x = 0;}
if (y > imgEle.height - zoomLens.offsetHeight) {y = imgEle.height - zoomLens.offsetHeight;}
if (y < 0) {y = 0;}
zoomLens.style.left = x + "px";
zoomLens.style.top = y + "px";
resultEle.style.backgroundPosition = "-" + (x * xPos) + "px -" + (y * yPos) + "px";
}
function currentCursonPos(e) {
var a, x = 0, y = 0;
e = e || window.event;
a = imgEle.getBoundingClientRect();
x = e.pageX - a.left;
y = e.pageY - a.top;
x = x - window.pageXOffset;
y = y - window.pageYOffset;
return {x : x, y : y};
}
}
</script>
</body>
</html>
输出
上述代码将产生以下输出:
