如何创建：图像缩放

学习如何创建图像缩放。

创建图像缩放

第一步 - 添加 HTML：

<div class="img-zoom-container">
  <img id="myimage" src="img_girl.jpg" width="300" height="240" alt="Girl">
  <div id="myresult" class="img-zoom-result"></div>
</div>

第二步 - 添加 CSS：

容器必须具有“相对”定位。

* {box-sizing: border-box;}
.img-zoom-container {
  position: relative;
}
.img-zoom-lens {
  position: absolute;
  border: 1px solid #d4d4d4;
  /*set the size of the lens:*/
  width: 40px;
  height: 40px;
}
.img-zoom-result {
  border: 1px solid #d4d4d4;
  /* set the size of the result div: */
  width: 300px;
  height: 300px;
}

kinga tatu - Ongeza JavaScript:

function imageZoom(imgID, resultID) {
  var img, lens, result, cx, cy;
  img = document.getElementById(imgID);
  result = document.getElementById(resultID);
  /* kumekisha lenzi: */
  lens = document.createElement("DIV");
  lens.kuwekaMwili("class", "img-zoom-lens");
  /* kuweka lenzi: */
  img.parentElement.kuwekaKufikia(lens, img);
  /* kumaliza uharibifu wa result DIV na lenzi: */
  cx = result.offsetWidth / lens.offsetWidth;
  cy = result.offsetHeight / lens.offsetHeight;
  /* kuingiza uhusiano wa mabaki ya result DIV: */
  result.style.image = "url('" + img.src + "')";
  result.style.size = (img.width * cx) + "px " + (img.height * cy) + "px";
  /* kama mtu anamuea kikao cha kikili au lenzi, kufanya mifano yoyote: */
  lens.kuona('mousemove', moveLens);
  img.kuona('mousemove', moveLens);
  /* pia kwa mifani ya mifungo: */
  lens.kuona('touchmove', moveLens);
  img.kuona('touchmove', moveLens);
  function moveLens(e) {}}
    var pos, x, y;
    /* Kupunguza uharibifu wa kipindi cha kina: */
    e.preventDefault();
    /* Kupata ukimwita kwa x na y: */
    pos = getCursorPos(e);
    /* Kukalenda uharibifu wa kichwa cha kina: */
    x = pos.x - (lens.offsetWidth / 2);
    y = pos.y - (lens.offsetHeight / 2);
    /* Kupunguza kichwa cha kina kwa uharibifu wa picha: */
    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;}
    /* Kusaidia uharibifu wa kichwa cha kina: */
    lens.style.left = x + "px";
    lens.style.top = y + "px";
    /* Kufichaa uharibifu wa kichwa cha kina: */
    result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "px";
  }
  function getCursorPos(e) {
    var a, x = 0, y = 0;
    e = e || window.event;
    /* Kupata ukimwita wa picha kwa x na y: */
    a = img.getBoundingClientRect();
    /* Kukalenda ukimwita kwa x na y kwa picha: */
    x = e.pageX - a.left;
    y = e.pageY - a.top;
    /* Kusikia uharibifu wa ukiaja wa mawasiliano: */
    x = x - window.pageXOffset;
    y = y - window.pageYOffset;
    kutumia {x : x, y : y};
  }
}

Kipindi cha 4 - Iniliazea uharibifu wa kubadilika:

<script>
imageZoom("myimage", "myresult");
</script>

亲自试一试