<!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <style> * {box-sizing: border-box;} .img-zoom-container { position: relative; } .img-zoom-lens { position: absolute; border: 1px solid #d4d4d4; /*设置镜头的大小:*/ width: 100px; height: 100px; } .img-zoom-result { border: 1px solid #d4d4d4; /*设置结果div的大小:*/ width: 300px; height: 300px; } </style> <script> function imageZoom(imgID, resultID) { var img, lens, result, cx, cy; img = document.getElementById(imgID); result = document.getElementById(resultID); /*创建镜头:*/ lens = document.createElement("DIV"); lens.setAttribute("class", "img-zoom-lens"); /*插入镜头:*/ img.parentElement.insertBefore(lens, img); /*计算结果DIV与lens的比值:*/ cx = result.offsetWidth / lens.offsetWidth; cy = result.offsetHeight / lens.offsetHeight; /*为结果DIV设置背景属性:*/ result.style.backgroundImage = "url('" + img.src + "')"; result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px"; /*当有人将光标移到图像或镜头上时执行函数:*/ lens.addEventListener("mousemove", moveLens); img.addEventListener("mousemove", moveLens); /* 也适用于触摸屏:*/ lens.addEventListener("touchmove", moveLens); img.addEventListener("touchmove", moveLens); function moveLens(e) { var pos, x, y; /*防止在图像上移动时可能发生的任何其他操作:*/ e.preventDefault(); /*获取光标的x和y位置:*/ pos = getCursorPos(e); /*计算镜头的位置:*/ x = pos.x - (lens.offsetWidth / 2); y = pos.y - (lens.offsetHeight / 2); /*防止镜头位于图像之外:*/ if (x > img.width - lens.offsetWidth) {x = img.width - lens.offsetWidth;} if (x < 0) {x = 0;} if (y > img.height - lens.offsetHeight) {y = img.height - lens.offsetHeight;} if (y < 0) {y = 0;} /*设置镜头的位置:*/ lens.style.left = x + "px"; lens.style.top = y + "px"; /*显示镜头“看到”的内容:*/ result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "px"; } function getCursorPos(e) { var a, x = 0, y = 0; e = e || window.event; /*获取图像的x和y位置:*/ a = img.getBoundingClientRect(); /*计算光标相对于图像的 x 和 y 坐标:*/ x = e.pageX - a.left; y = e.pageY - a.top; /*考虑任何页面滚动:*/ x = x - window.pageXOffset; y = y - window.pageYOffset; return {x : x, y : y}; } } </script> </head> <body> <h1>图像缩放</h1> <p>鼠标悬停在图片上:</p> <div class="img-zoom-container"> <img id="myimage" src="img_girl.jpg" width="300" height="240"> <div id="myresult" class="img-zoom-result"></div> </div> <p>结果可以放在页面的任何地方,但必须有类名“img-zoom-result”。</p> <p>确保图像和结果都有 ID。 确保 ID 是唯一的 在 javaScript 启动缩放效果时使用。</p> <script> // 初始化缩放效果: imageZoom("myimage", "myresult"); </script> </body> </html>
标签:镜头,img,缩放,px,lens,result,图像 From: https://www.cnblogs.com/tcyweb/p/17741987.html